xvEPA
United States
Environmental Protection
Agency
Air Pollution Training Institute
MD20
Environmental Research Center
Research Triangle Park, NC 27711
EPA 460/2-82-021
August 1983
Air
APTI
Correspondence Course 438
Reference and Automated
Equivalent Measurement
Methods for Ambient Air
Monitoring
Guidebook
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Notice
This is not an official policy and standards document. The opinions and selections
are those of the authors and not necessarily those of the Environmental Protection
Agency. Every attempt has been made to represent the present state of the art as
well as subject areas still under evaluation. Any mention of products or organizations
does not constitute endorsement by the United States Environmental Protection
Agency.
11
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Table of Contents
Page
Course Introduction 0-1
Section 1. Reference Method for Sulfur Dioxide 1-1
Review Exercise 1-3
Review Exercise Answers 1-8
Section 2. Automated Equivalent Measurement Methods for Sulfur Dioxide.. ,2-1
Review Exercise 2-3
Review Exercise Answers 2-9
Section 3. Reference Methods for Ozone 3-1
Review Exercise 3-3
Review Exercise Answers 3-8
Section 4. Reference Method for Total Suspended Paniculate Matter (TSP)... 4-1
Review Exercise 4-3
Review Exercise Answers 4-9
Section 5. Reference Methods for Carbon Monoxide 5-1
Review Exercise 5-3
Review Exercise Answers 5-7
Section 6. Reference Methods for Nitrogen Dioxide 6-1
Review Exercise 6-3
Review Exercise Answers 6-7
Section 7. Reference Method for Lead 7-1
Excerpts of Section 2.8 of
Quality Assurance Handbook for Air Pollution Measurement Systems 7-3
Review Exercise 7-43
Review Exercise Answers 7-48
Section 8. Automated Analyzers for Nonmethane Organic Compounds 8-1
Review Exercise 8-3
Review Exercise Answers 8-10
in
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Course Introduction
Overview of Course
Course Description
This training course is a thirty-hour correspondence course concerning EPA-
designated reference and equivalent measurement methods for ambient air quality
monitoring. Automated nonmethane organic compound analyzers are also dis-
cussed. Course topics include the following:
• reference and automated equivalent measurement methods for sulfur dioxide
• reference measurement methods for ozone
• reference measurement method for total suspended paniculate matter
• reference measurement methods for carbon monoxide
• reference measurement methods for nitrogen dioxide
• reference measurement method for lead
• automated analyzers for nonmethane organic compounds.
Course Goal
To familiarize you with EPA-designated reference and automated equivalent
measurement methods for ambient air quality monitoring and air quality analyzers
for nonmethane organic compounds.
Course Objectives
After completing this course, you should be able to—
1. describe the manual reference measurement methods for sulfur dioxide, total
suspended paniculate matter, and lead, and recognize considerations for the
operation, maintenance, calibration, and auditing of equipment used in the
methods; and
2. describe considerations for the operation, maintenance, calibration, and
auditing of air quality analyzers for sulfur dioxide, ozone, carbon monoxide,
nitrogen dioxide, and nonmethane organic compounds.
0-1
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Sequence, Section Titles, and Trainee Involvement Time
Trainee involvement
Section number Section title time (hours)
1 Reference Method for Sulfur Dioxide 3
2 Automated Equivalent Measurement
Methods for Sulfur Dioxide
3 Reference Methods for Ozone
Quiz 1 ^
4 Reference Method for Total Suspended 4
Paniculate Matter (TSP)
5 Reference Methods for Carbon Monoxide 3
6 Reference Methods for Nitrogen Dioxide 3
Quiz 2 V4
7 Reference Method for Lead 3V£
8 Automated Analyzers for Nonmethane 4
Organic Compounds
Final Exam 1V£
Requirements for Successful Completion of this Course
In order to receive three Continuing Education Units (CEUs) and a certificate of
course completion you must fulfill the following requirements:
• take two supervised quizzes and a supervised final examination
• achieve a final course grade of at least 70 (out of 100) determined
as follows:
• 20% from Quiz 1
• 20% from Quiz 2
• 60% from the final examination
Use of Course Materials
Necessary Materials
• APTI Correspondence Course 438 Reference and Automated Equivalent
Measurement Methods for Ambient Air Monitoring: Guidebook
• EPA 450/2-81-018b, APTI Course 464 Analytical Methods for Air Quality
Standards: Student Manual, Second Edition
• EPA 600/4-81-015, Technical Assistance Document for the Calibration and
Operation of Automated Ambient Non-Methane Organic Compound
Analyzers
• pencil or pen
• calculator (optional, but recommended)
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Use of this Guidebook
Relationship Between Guidebook and Assigned Reading Materials
This guidebook directs your progress through the reference texts APT! Course 464
Analytical Methods for Air Quality Standards: Student Manual, Second Edition
and Technical Assistance Document for the Calibration and Operation of
Automated Non-Methane Organic Compound Analyzers and through the excerpts
of Section 2.8 of Quality Assurance Handbook for Air Pollution Measurement
Systems, which are contained in this guidebook.
Description of Guidebook Sections
This guidebook contains reading assignment sections that correspond to lessons of
the course.
Each section contains the following:
• reading assignment
• section's learning goal and objectives
• reading guidance
• review exercise
Please do not write in this guidebook.
Instructions for Completing the Quizzes and Examinations
• You should have received, along with this guidebook, a separate sealed
envelope containing two quizzes and a final examination.
• You must arrange to have someone serve as your test supervisor.
• You must give the sealed envelope containing the quizzes and examination to
your test supervisor.
• At the designated times during the course, under the supervision of your test
supervisor, complete the quizzes and the final exam.
• After you have completed each quiz or the exam, your test supervisor must
sign a statement on the quiz/exam answer sheet certifying that the quiz/exam
was administered in accordance with the specified test instructions.
• After signing the answer sheet, your test supervisor must mail the quiz/exam
and its answer sheet to the following address:
Air Pollution Training Institute
Environmental Research Center
MD20
Research Triangle Park, NC 27711
• After completing a quiz, continue with the course. Do not wait for quiz
results.
• Quiz/exam and course grade results will be mailed to you.
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// you have questions, contact the Air Pollution Training Institute:
Air Pollution Training Institute
Environmental Research Center
MD20
Research Triangle Park, NC 27711
Telephone numbers:
Commercial: (919) 541-2401
FTS: 629-2401
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Section 1
Reference Method for Sulfur Dioxide
Reading Assignment
Pages 1-1 through 2-12 of EPA 450/2-81-018b APTI Course 464 Analytical
Methods for Air Quality Standards: Student Manual.
Reading Assignment Topics
• Introduction to reference and equivalent measurement methods
• Reference method for sulfur dioxide
Learning Goal and Objectives
Learning Goal
The purpose of this section is to familiarize you with general information about
reference and equivalent measurement methods and with specific information con-
cerning the sulfur dioxide reference method.
Learning Objectives
At the end of this section, you should be able to—
1. identify pollutants having National Ambient Air Quality Standards
(NAAQS),
2. define primary and secondary NAAQS,
3. locate, in the Code of Federal Regulations, the NAAQS, descriptions of the
reference methods and reference measurement principles, and designation
requirements for reference and equivalent methods,
4. identify the two general types of reference and equivalent methods,
5. describe requirements for the designation of automated reference methods
and for the designation of manual and automated equivalent methods,
6. recognize sampling and analytical equipment used in the sulfur dioxide
reference method,
7. recognize two chemical reactions involved in the sampling and analysis of
sulfur dioxide by the reference method,
8. describe the sodium sulfite and permeation tube calibration methods for the
sulfur dioxide reference method,
9. identify and describe the removal of three potential interferences in the sulfur
dioxide reference method,
10. recognize and describe solutions for eight reagent problems of the sulfur
dioxide reference method, and
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11. describe three types of audits that should be included in a quality
assurance program for the sulfur dioxide reference method.
Reading Guidance
9 When you have finished the reading assignment, complete the review exercise
for Section 1. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), proceed to Section 2
of this guidebook.
1-2
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Review Exercise
Now that you've completed the assignment for Section 1, please answer the follow-
ing questions. These will help you determine whether you are mastering the
material.
For each of questions 1 through 3, match the item with its location in the Code of
Federal Regulations.
1. National Ambient Air Quality Standards (NAAQS) a. Title 40 Part 53
2. descriptions of the reference methods and reference b. Title 40 Part 50
measurement principles for monitoring pollutants c. Appendixes of
that have NAAQS Title 40 Part 50
3. designation requirements for reference and
equivalent methods
4. Which of the following is a(are) general type(s) of reference methods?
a. manual method
b. automated method
c. both a and b, above
d. none of the above
5. Which of the following is a(are) general type(s) of equivalent methods?
a. manual method
b. automated method
c. both a and b, above
d. none of the above
6. True or False? In order to be designated an equivalent method, a manual
method must demonstrate a consistent relationship to the manual reference
method or to the automated reference methods.
7. Which of the following is(are) necessary for the designation of an automated
equivalent method?
a. Performance specifications for automated methods must be met.
b. Consistent relationship requirements must be met.
c. both a and b, above
d. none of the above
8. Which of the following is(are) necessary for the designation of an automated
reference method?
a. Performance specifications for automated methods must be met.
b. The reference measurement principle must be used.
c. both a and b, above
d. none of the above
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9. National Ambient Air Quality Standards (NAAQS) have been established for
which of the following?
a. sulfur dioxide
b. total suspended paniculate matter
c. mercury
d. both a and c, above
e. both a and b, above
10. Which of the following has no NAAQS?
a. nitric oxide
b. nitrogen dioxide
c. lead
d. ozone -
11. Primary NAAQS are established to protect public (?)
a. health
b. welfare
c. health and welfare
d. none of the above
12. Secondary NAAQS are established to protect public (?)
a. health
b. welfare
c. health and welfare
d. none of the above
For each of questions 13 through 17, match the chemical with its use in the
reference method for sulfur dioxide.
13. formaldehyde a. color development of sample solution
14. pararosaniline b. complexing of sulfur dioxide in
15. potassium tetrachloromercurate absorbing solution
(TCM) c. destruction of nitrite in sample solution
16. sulfamic acid d. removal of heavy metal interference
17. EDTA/phosphoric acid
18. True or False? Initial and final sample air flow rates of sulfur dioxide sampling
trains must be determined at the sampling sites.
19. Which of the following is a(are) component(s) of a 24-hour sampling train for
sulfur dioxide?
a. vacuum pump
b. absorber tube
c. moisture trap
d. a and b, above
e. a, b, and c, above
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20. Which of the following devices may be used for controlling the flow of sample
air through a sulfur dioxide sampling train?
a. rotameter combined with a needle valve
b. critical orifice
c. spirometer
d. a and b, above
e. a, b, and c, above
21. True or False? A membrane paniculate filter should be placed downstream of
a critical orifice used in a sulfur dioxide sampling train.
22. In the sulfite solution calibration method for sulfur dioxide analysis, the stan-
dardized sulfite solution is diluted with (?)
a. sodium thiosulfate
b. iodine
c. TCM
d. starch solution
23. True or False? Reaction time and temperature must be carefully controlled
during the analysis of sulfur dioxide samples and standard solutions.
24. As light of an appropriate wavelength passes through the sulfur dioxide solu-
tions, the strength of the light beam (?) in direct proportion to
a(an) (?) in the concentrations of the solutions.
a. increases, increase
b. decreases, increase
c. increases, decrease
25. Under the conditions described below, the sulfur dioxide concentration
measured by the sulfur dioxide reference method is (?) j*g/std m3-
a. 0.3
b. 3 Given: Absorbance of sample solution: 0.190 absorbance units
c. 30 Absorbance of reagent blank: 0.160 absorbance units
d. 300 Calibration factor (B,): 31 /ig/absorbance unit
Volume of absorber solution analyzed (V«): 5 mL
Total volume of solution in absorber (V6): 50 mL
Volume of air sampled: 310 L, at reference conditions
of 25 °C and 760 mm Hg
26. True or False? An SO2 permeation tube consists of a tube that is partially filled
with liquefied SOj. The gaseous SOj above the liquid is able to permeate the
walls of the tube.
27. Which of the following is an(are) important consideration(s) when using a
permeation tube system?
a. The permeation tube must be kept at a constant temperature.
b. All gas flow rates must be measured accurately.
c. Dilution air must be saturated with water vapor.
d. only a and b, above
e. only b and c, above
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28. Under the conditions described below, what is the SO» concentration (/tg/std m3)
generated by the permeation system?
a. 0.2
b. 20 Given: Permeation rate of SO2 from tube: 1.000 /tg/min
c. 202 Flow rate of dilution air: 4.950 std L/min
d. 200 Flow rate of inert carrier gas: 0.050 std L/min
29. True or False? A reagent blank should be analyzed when analyzing standard or
sample solutions by the SO2 reference method.
30. Which of the following eliminates ozone interference in the SO2 reference
method?
a. a 20-minute time delay between sampling and analysis
b. sulfamic acid
c. EDTA
d. formaldehyde
31. Under which of the following conditions should TCM reagent not be used for
collecting SO2?
a. The pH of the TCM reagent is between 3 and 5.
b. A precipitate is present in the TCM reagent.
c. both a and b, above
d. none of the above
32. A sulfur dioxide sample must be invalidated if the difference between its initial
and final sampling standard flow rates is greater than (?) percent.
a. 1
b. 2
c. 5
d. 10
For each of questions 33 and 34, match the chemical with its characteristic.
33. TCM reagent a. poisonous
34. monochlorosulfantomercurate b. subject to decomposition by heat and
complex sunlight
35. Which of the following is an(are) important consideration(s) concerning the
spectrophotometer used in the SO2 reference method?
a. The band width is important and should be periodically checked.
b. The absorbance cells should be washed after use to prevent staining.
c. Absorbance readings should be made as quickly as possible.
d. all of the above
36. True or False? Pararosaniline used in the SO2 reference method must meet
specifications described in the method.
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37. True or False? All water used in preparing reagents for the SO, reference
method must contain oxidants.
38. Which of the following activities should be included in a quality-assurance
program for the SO, reference method?
a. audits of sampler flow measuring devices
b. analyses of analytical control samples
c. data processing audits
d. all of the above
39. True or False? Audits for the SO, reference method should be performed by
persons not routinely involved in the sampling and analysis of SO,.
40. In the SO» reference method, SO» reacts with (?) to form a
monochlorosulfantomercurate complex.
a. sulfamic acid
b. formaldehyde
c. pararosaniline
d. none of the above
41. In the SO, reference method, a monochlorosulfantomercurate complex
reacts with pararosaniline and (?) to form a pararosaniline methyl
sulfonic acid.
a. sulfamic acid
b. formaldehyde
c. EDTA
d. none of the above
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Section 1
Review Exercise Answers
Page(s) of Analytical Methods
for Air Quality Standards:
Student Manual
1. b 1-1
2. c 1-1
3. a 1-1
4. c 1-1
5. c 1-2
6. True 1-2
7. c 1-2
8. c 1-1
9. e 1-1
10. a 1-1
11. a 1-1
12. b 1-1
13. a 2-2
14. a 2-2
15. b 2-1
16. c 2-2
17. d 2-8
18. True 2-4
19. e 2-2,2-3
20. d 2-2
21. False 2-3, 2-4
22. c 2-5
23. True 2-5
24. b 2-5
25. c 2-6
26. True 2-6
27. d 2-6
28. d 2-7
29. True 2-8
30. a 2-8
31. b 2-9
32. c 2-4
33. a 2-10
34. b 2-9
35. d 2-10
36. True 2-10
1-8
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Page(s) of Analytical Methods
for Air Quality Standards:
Student Manual
37. False 2-10
38. d 2-11
39. True 2-10
40. d 2-1
41. b 2-2
1-9
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Section 2
Automated Equivalent Measurement
Methods for Sulfur Dioxide
Reading Assignment
Pages 3-1 through 3-19 of EPA 450/2-81-018b APTI Course 464 Analytical
Methods for Air Quality Standards: Student Manual.
Reading Assignment Topics
Amperometric instruments
Flame photometric instruments
Fluorescence instruments
Second derivative spectroscopic instruments
Conductimetric instruments
Learning Goal and Objectives
Learning Goal
The purpose of this section is to familiarize you with automated equivalent
methods for monitoring sulfur dioxide.
Learning Objectives
At the end of this section, you should be able to—
1. identify two advantages of using continuous instrumental methods for
monitoring ambient air quality;
2. describe measurement principles used by amperometric, flame photometric,
fluorescence, second derivative spectroscopic, and conductimetric sulfur diox-
ide monitors;
3. recognize and identify advantages and disadvantages of conductimetric,
amperometric, second derivative spectroscopic, flame photometric, and
fluorescence sulfur dioxide monitors;
4. identify and describe the removal of six potential interferences associated with
the use of amperometric, flame photometric, and fluorescence sulfur dioxide
monitors;
5. describe calibration, maintenance, and trouble-shooting procedures for
amperometric, flame photometric, fluorescence, second derivative spec-
troscopic, and conductimetric sulfur dioxide monitors;
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6. recognize the need for frequent zero and span checks of automated air quality
monitors; and
7. identify a quality-assurance reference text for automated ambient-air-quality
monitors.
Reading Guidance
• Refer often to the figures of the assigned reading material as you progress
through the assignment.
• When you have finished the reading assignment, complete the review exercise
for Section 2. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), proceed to Section 3
of this guidebook.
2-2
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Review Exercise
Now that you've completed the assignment for Section 2, please answer the follow-
ing questions. These will help you determine whether you are mastering the
material.
1. Which of the following is an(are) advantage(s) of using continuous
instrumental methods for monitoring ambient air quality?
a. real-time data output
b. ability to transmit data directly into computerized data acquisition and
telemetry systems
c. both a and b, above
d. none of the above
2. amperometric
3. flame photometric
4. second-derivative spectroscopic
5. conductimetric
6. fluorescence
For each of questions 2 through 6, match the instrumental measurement principle
with its description.
a. uses ion changes in an acidified
hydrogen peroxide solution to measure
gaseous pollutant concentration
b. uses an electrical current generated by
oxidation-reduction reactions in an elec-
trolytic cell to measure gaseous pollutant
concentration
c. relates the slope and curvature
characteristics of energy absorption
bands to gaseous pollutant concentration
d. uses the energy emitted by a pollutant in
a hydrogen-rich flame to measure the
pollutant's concentration
e. uses the energy emitted by "excited
molecules" (molecules having excess
energy) to measure pollutant
concentration
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For each of questions 7 through 10, match the analyzer type with its advantage(s).
7. flame photometric
8. conductimetric/amperometric
9. second-derivative
spectroscopic
10. fluorescence
a. highly specific for pollutant
monitored; no support gases are needed
for its operation
b. no support gases are needed for its
operation
c. no support gases are needed for its
operation; relatively insensitive to
temperature and sample-air flow
variations
d. highly specific for sulfur compounds; no
chemical solutions are needed for its
operation; low maintenance
requirements; high sensitivity for sulfur
compounds; fast response
For each of questions 11 through 15, match the analyzer type with its
disadvantage(s).
11. fluorescence
12. second-derivative
spectroscopic
13. flame photometric
14. amperometric
15. conductimetric
a. must use a scrubber to remove sample -
air components that react with
halogens
b. complexity of measurement principle
c. if monitoring for SO2, must use a
scrubber to remove other sulfur com-
pounds from the sample air; potential
carbon dioxide interference; must use
hydrogen
d. must use a scrubber to remove hydrocar-
bons and water vapor from the sample
air
e. must use a peroxide solution that must
be replenished frequently; inherent
cycling procedure; variability of response
due to interferences
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For each of questions 16 through 19, match the analyzer type with its appropriate
diagram.
16. amperometric
17. flame photometric
18. fluorescence
19. second-derivative spectroscopic
a.
Monochromator
Sample
air Mirror
fteSS^jjf- Wavelength
scanner
, "T, Photomultiplier
Sample cell tube r -
Recorder
Signal
" analysis
electronics
Ultraviolet
source
b.
Photomultiplier
tube
210-nm bandpass
filter
Exhaust
350-nrn bandpass niter
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c.
Exhaust
394-nrn bandpass
filter Photomultiplier
tube
Electronics
d.
Sample air
Sensor electrode •
Generator electrode
Reference
electrode
Signal
processor
Basic
amplifier
Meter
For each of questions 20 through 23, match the SO2 analyzer type with its potential
major interferences.
20. amperometric
21. flame photometric
22. fluorescence
a. sulfur compounds
b. sulfur compounds, CO2, and
phosphorous
c. water vapor, oxygen, and aromatic
hydrocarbons
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For each of questions 23 through 28, match the SOt analyzer interference with an
appropriate method of eliminating the interference.
23. sulfur compounds a. pass sample air through an appropriate
24. CO, scrubber before SO, is measured
25. phosphorous b. pass sample air through a permeation
26. water vapor dryer before SO2 is measured
27. oxygen c. in calibrating the analyzer, obtain
28. aromatic hydrocarbons dilution air from the analyzer's sampling
manifold; remove sulfur compounds from
dilution air before calibrating the
analyzer
29. Which of the following can be used for calibrating SOt analyzers?
a. UV photometer
b. permeation tube system
c. standard gas cylinder/dilution system
d. a and b, above
e. b and c, above
30. True or False? At least two different concentrations of SOZ should be used for
calibrating an SOj analyzer.
31. Calibration gas should be introduced through the (?) of an auto-
mated air analyzer.
a. span port
b. zero port
c. sample handling system (probe)
d. both a and b, above
32. True or False? It is prudent to conduct frequent zero and single-point calibra-
tion checks of automated air analyzers.
33. True or False? COj tends to increase the response of flame photometric
analyzers to SO2.
34. True or False? Quenching occurs when an excited molecule loses its excess
energy by colliding with another molecule.
35. Which of the following is a(are) component(s) of a clean-air package for
generating zero air for calibrating flame photometric SO2 analyzers?
a. activated-charcoal filters
b. molecular sieve
c. both a and b, above
d. none of the above
36. True or False? Burner assemblies of flame photometric SO2 analyzers must be
cleaned periodically.
37. True or False? Sample air paniculate filters and scrubbers must be replaced or
cleaned periodically.
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38. True or False? Electrolyte solutions in amperometric SO2 analyzers do not have
to be replaced.
39. Which of the following is a(are) possible action(s) for eliminating a low or
"noisy" response from a flame photometric SO2 analyzer?
a. clean the analyzer's burner assembly
b. replace the analyzer's photomultiplier tube (pmt)
c. replace the analyzer's optical window
d. all of the above
40. True or False? Analyzer sample inlet lines, limiting orifices, flow restricting
capillaries, and rotameters should be checked often.
41. True or False? Hydrogen lines, regulators, and solenoid valves do not have to
be leak checked often.
42. Which of the following contain(s) quality assurance information for automated
ambient air quality analyzers?
a. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume II
b. Quality Assurance Handbook for Air Pollution Measurement Systems,
Volume III
c. Methods for Air Sampling and Analysis
d. all of the above
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Section 2
Review Exercise Answers
Page(s) of Analytical Methods
for Air Quality Standards:
Student Manual
1. c 3-1
2. b 3-1, 3-2
3. d 3-6
4. c 3-17
5. a 3-19
6. e 3-12
7. d 3-9
8. b 3-4,3-19
9. a 3-18
10. c 3-16
11. d 3-16
12. b 3-19
13. c 3-7,3-10
14. a 3-5
15. e 3-19
16. d 3-3
17. c 3-9
18. b 3-15
19. a 3-18
20. a 3-5
21. b 3-7, 3-10
22. c 3-16
23. a 3-5,3-7
24. c 3-11
25. a 3-10
26. b 3-14
27. c 3-16
28. a 3-16
29. e 3-4
30. False .- 3-4
31. c 3-4
32. True 3-4
33. False 3-10
34. True 3-12
35. a 3-11
36. True 3-11
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Page(s)of Analytical Methods
for Air Quality Standards:
Student Manual
37. True 3-5
38. False 3-5
39. d 3-11
40. True 3-10, 3-11
41. False 3-10, 3-11
42. a 3-19
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Section 3
Reference Methods for Ozone
Reading Assignment
Pages 4-1 through 4-17 of EPA 450/2-81-018b APTI Course 464 Analytical
Methods for Air Quality Standards: Student Manual.
Reading Assignment Topics
• Reference measurement principle
• Description of a typical ozone monitor
• Ultraviolet photometric calibration of ozone monitors
• Maintenance and troubleshooting of ozone monitors and calibration
equipment
• Quality assurance for ozone monitors
Learning Goal and Objectives
Learning Goal
The purpose of this section is to familiarize you with reference methods for
monitoring ozone.
Learning Objectives
At the end of this section, you should be able to—
1. describe the ozone reference measurement principle,
2. describe a typical chemiluminescence ozone analyzer,
3. convert between ozone concentrations expressed in parts per million (ppm)
and those expressed in micrograms per standard cubic meter (/tg/std m3),
4. describe the measurement principle used by ultraviolet (UV) photometers,
5. describe an ozone generator and a typical UV photometer,
6. define and recognize two advantages of ozone transfer standards,
7. recognize two precautions for the use of ethylene,
8. identify a potential interference associated with the use of chemilumi-
nescence ozone analyzers,
9. describe maintenance procedures for chemiluminescence ozone analyzers,
10. troubleshoot air quality monitors by using strip chart recorder traces,
11. recognize at least four situations that require an analyzer to be recalibrated,
and
12. use zero and span data to determine the need for an analyzer recalibration
and for data validation.
3-1
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Reading Guidance
• Refer often to the figures of the assigned reading material as you progress
through the assignment.
• When you have finished the reading assignment, complete the review exercise
for Section 3. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), take Quiz 1. Follow
the directions listed in the Course Introduction section of this guidebook.
• After completing Quiz 1, proceed to Section 4 of this guidebook.
3-2
-------
Review Exercise
Now that you've completed the assignment for Section 3, please answer the follow-
ing questions. These will help you determine whether you are mastering the
material.
1. The ozone reference measurement principle is (?)
a. ultraviolet photometry
b. gas-phase chemiluminescence
c. nondispersive infrared spectroscopy
d. flame photometry
2. The reference calibration procedure for ozone analyzers employs
a. ultraviolet photometry
b. gas-phase chemiluminescence
c. nondispersive infrared spectroscopy
d. flame photometry
3. (?) ozone analyzers use the light emitted because of the reaction of
ozone with (?) to measure ozone concentration.
a. Ultraviolet photometric, ethylene
b. Ultraviolet photometric, hydrogen
c. Chemiluminescent, ethylene
d. Chemiluminescent, hydrogen
4. Which of the following measurement principles is(are) used by analyzers that
have been designated equivalent measurement methods for ozone?
a. ultraviolet photometry
b. gas-solid chemiluminescence
c. both a and b, above
d. gas-phase chemiluminescence
e. a, b, andd, above
5. Which of the following is a(are) component(s) of a gas-phase Chemiluminescent
ozone analyzer?
a. ultraviolet lamp
b. reaction chamber
c. photomultiplier tube
d. both a and c, above
e. both b and c, above
3-3
-------
6. In a gas-phase chemiluminescent ozone analyzer, sample air and ethylene are
mixed in a(n) (?)
a. ozone generator
b. vacuum pump
c. photomultiplier tube
d. reaction chamber
7. True or False? In a gas-phase chemiluminescent ozone analyzer, the light
energy emitted by the ozone-ethylene reaction is converted to an electrical
signal by a photomultiplier tube.
8. In a gas-phase chemiluminescent ozone analyzer, as the ozone concentration of
the sample air (?) , the light energy emitted by the ozone-ethylene
reaction (?)
a. decreases, increases
b. increases, decreases
c. increases, increases
9. True or False? Sample-air and ethylene flow rates must be closely controlled
when using gas-phase chemiluminescent ozone analyzers.
10. True or False? Too low an ethylene flow rate could result in an erroneously
high ozone-concentration reading from a chemiluminescent ozone analyzer.
11. True or False? If ethylene flow through a chemiluminescent ozone analyzer is
too high, an explosion could occur.
12. At 25°C and 760 mm Hg, 0.100 ppm of ozone (molecular weight: 48 jig//unole)
is equal to (?) /tg/std ms of ozone.
a. 196
b. 51
c. 0.196
d. 0.051
13. Which of the following can be used to prepare ozone calibration gas?
a. compressed gas cylinders containing known amounts of ozone
b. ozone permeation tubes
c. ultraviolet-light sources
d. all of the above
14. True or False? An ultraviolet photometer determines ozone concentration by
measuring the absorption of ultraviolet light.
15. As ultraviolet light of an appropriate wavelength passes through an air sample
containing ozone, the intensity of the light beam decreases as the (?)
increases.
a. ozone concentration of the air sample
b. optical-path length
c. both a and b, above
d. none of the above
3-4
-------
16. Ozone can be produced by irradiating with ultraviolet light the (?)
present in ozone-free air.
a. carbon dioxide
b. water vapor
c. oxygen
d. none of the above
17. Which of the following must be kept constant in order to generate constant
amounts of ozone using an ultraviolet ozone generator?
a. intensity of ultraviolet light
b. flow rate of ozone-free air
c. oxygen concentration of ozone-free air
d. both a and b, above
e. all of the above
18. Which of the following is a(are) component(s) of a UV photometer?
a. low-pressure mercury discharge lamp
b. absorption cell(s)
c. detector(s)
d. all of the above
19. Which of the following is(are) used by UV photometers in measuring ozone
concentrations?
a. current-to-frequency converters
b. counters
c. interference cells
d. both a and b, above
e. both a and c, above
20. Which of the following can be used as ozone transfer calibration standards?
a. ozone analyzers
b. manual analytical procedures
c. ozone generators
d. all of the above
21. Which of the following is an(are) advantage(s) of using ozone transfer calibra-
tion standards?
a. allows the calibrations of ozone analyzers at several monitoring sites to be
referenced to one centrally located UV photometer
b. eliminates the transporting of UV photometers to monitoring sites
c. both a and b, above
22. True or False? Measurements of very low ozone concentrations made by gas-
phase chemiluminescent analyzers can be affected by humid sample air.
3-5
-------
23. Which of the following is(are) necessary to prevent the accumulation of
explosive concentrations of ethylene in monitoring shelters containing gas- phase
chemiluminescent ozone analyzers?
a. vent chemiluminescent ozone analyzers to the outside air
b. leak check ethylene gas handling systems
c. use an ethylene scrubber
d. both a and b, above
e. both a and c, above
24. Which of the following components of a gas-phase chemiluminescent ozone
analyzer must be checked periodically?
a. Teflon® sample-air inlet filter
b. ethylene and sample- air pressures and flow rates
c. gas-handling systems (for leaks)
d. all of the above
25. True or False? The sintered filter located in the ethylene gas handling system
of a gas-phase chemiluminescent ozone analyzer never has to be replaced.
For each of questions 26 through 30, match the strip-chart recorder trace with its
possible causes.
26.
1
Straight line trace sustained
for several hours
27.
o n 0 a a n^ a a a ~i gas o
Drift, gradually increasing
or decreasing
a. stoppage of sample air or
ethylene flow; electrical failure
in detection circuit
b. unusually large decrease in
shelter temperature or electrical
line voltage
c. shelter temperature fluctuations
beyond operating temperature
limits of analyzer
d. electrical instability of analyzer
or a dirty photomultiplier tube
window
e. a leak in or gradual clogging of
analyzer's gas- handling system;
failure of detector-cell
„
temperature controller
Wide solid trace, or with
sharp "spikes"
3-6
-------
29.
. . r . . " .
Cyclic pattern with
definite time period
30.
aoanxouoociaaaof»or.n-.
Recorded trace drops below
baseline for periods of time,
possibly returning
31. In which of the following situations should an air-quality analyzer be
recalibrated?
a. after any repair that may affect the analyzer's calibration
b. following the physical relocation of the analyzer
c. when there is any indication of possible significant inaccuracy of the
analyzer
d. both a and c, above
e. a, b, and c, above
32. True or False? Analyzer zero and span drift limits can be used to determine
the need for analyzer recalibration.
33. True or False? Analyzer zero and span drift limits cannot be used for data
validation.
34. True or False? Visual evaluation of strip chart recorder traces can be used for
data validation.
3-7
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Section 3
Review Exercise Answers
Page(s) of Analytical Methods
for Air Quality Standards:
Student Manual
1. b 4-1
2. a 4-1
3. c 4-1,4-2
4. c 4-1,4-2
5. e 4-2,4-3
6. d 4-3,4-4
7. True 4-3
8. c 4-2
9. True 4-2
10. False . ..4-2
11. True 4-2
12. a 4-5
13. c 4-5,4-8
14. True 4-5
15. c 4-6
16. c 4-8
17. e 4-8
18. d 4-9,4-10
19. d 4-10
20. d 4-12
21. c 4-11, 4-12
22. True 4-13
23. d : 4-13
24. d 4-17
25. False 4-17
26. a 4-13,4-14
27. e 4-13,4-14
28. d 4-13,4-14
29. c 4-13,4-14
30. b 4-13,4-14
31. e 4-15
32. True 4-15, 4-16
33. False 4-15, 4-16
34. True 4-17
3-8
-------
Section 4
Reference Method for Total
Suspended Particulate Matter (TSP)
Reading Assignment
Pages 5-1 through 5-29 of EPA 450/2-81-018b APTI Course 464 Analytical
Methods for Air Quality Standards: Student Manual.
Reading Assignment Topics
Description of the high volume sampler
Filter handling
Calibration of the high volume sampler
Sampling and analysis procedure for TSP
Factors affecting high volume sampling accuracy and precision
Quality assurance considerations
Learning Goal and Objectives
Learning Goal
The purpose of this section is to familiarize you with the reference method for
measuring total suspended paniculate matter.
Learning Objectives
At the end of this section, you should be able to—
1. recognize the use of a high volume sampler in the TSP reference method,
2. recognize at least three major components of a high volume sampler,
3. identify and give the locations of at least five components of a calibration
set-up for calibrating a high volume sampler orifice-type flow rate transfer
standard,
4. recognize that a flow rate transfer standard is needed to calibrate a high
volume sampler's flow rate measuring device,
5. compare a calibration curve for a high volume sampler flow rate transfer
standard to a high volume sampler flow rate measuring device calibration
curve,
6. identify and describe how to minimize potential sources of error in high
volume sampling,
7. recognize the use of Reference Flow (ReF) devices for auditing flow rate
calibrations of high volume samplers,
4-1
-------
8. identify at least four components of a high volume sampler that need
periodic cleaning or replacement,
9. recognize at least four reasons to use a shelter when a high volume sampler
is used to sample suspended paniculate matter,
10. calculate total suspended paniculate matter concentration from high volume
sampling and analysis data,
11. recognize at least three advantages of glass-fiber filters and at least two
disadvantages of cellulose filters,
12. describe in sequence the activities involved in the reference method for TSP,
and
13. recognize at least seven items that should be checked during performance
and systems audits.
Reading Guidance
• Refer often to the equations and figures of the assigned reading material as
you progress through the assignment.
• When you have finished the reading assignment, complete the review exercise
for Section 4. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), proceed to Section 5
of this guidebook.
4-2
-------
Review Exercise
Now that you've completed the assignment for Section 4, please answer the follow-
ing questions. These will help you determine whether you are mastering the
material.
1. Which of the following is a(are) major component(s) of a high volume
sampler?
a. modified vacuum-sweeper motor
b. stainless steel filter holder
c. photodetector
d. both a and b, above
e. both a and c, above
2. Which of the following is a(are) reason(s) for the use of a shelter when sam-
pling suspended paniculate matter using a high volume sampler?
a. Shelter protects filter from direct impingement of paniculate matter.
b. Shelter uniformly distributes paniculate matter over the filter surface.
c. Shelter prevents birds from damaging filter.
d. both a and b, above
e. both b and c, above
3. True or False? When using a high volume sampler, the sampling flow rate
affects the size of panicles collected.
4. Which of the following is not a reason for the use of glass-fiber filters in
routine high volume sampling?
a. They have collection efficiencies of at least 99%.
b. They have low resistance to air flow.
c. They have low affinity for moisture.
d. They are suitable for the analysis of many organic and inorganic paniculate
pollutants.
e. They cost less than do other filters.
5. In order to eliminate weight errors due to small amounts of moisture, both
unexposed and exposed glass-fiber filters should be equilibrated at
(?) °C and less than (?) percent relative humidity for 24 hours
before weighing.
a. 0 to 5, 50
b. 15 to 35, 25
c. 15 to 30, 50
d. 15 to 35, 75
6. True or False? Blank concentrations of pollutants in clean glass-fiber filters
should be taken into account when analyzing exposed filters for pollutants.
4-3
-------
7. Which of the following is a(are) disadvantage(s) of using cellulose filters for
high volume sampling?
a. By rapidly clogging, they cause sampling flow rates to dramatically
decrease.
b. They have low metal content.
c. They enhance the artifact formation of sulfates and nitrates.
d. both a and c, above
e. both b and c, above
8. True or False? Folding or creasing a high volume filter before sampling may
cause erroneous flow patterns through the filter during sampling.
9. True or False? If an exposed high volume filter's border is fuzzy or nonexistent,
sample air may have leaked around the filter's gasket during sampling.
10. True or False? For transport to the laboratory for analysis after sampling, an
exposed high volume filter should be folded in half lengthwise so that collected
paniculate matter on one half of the filter does not touch collected paniculate
matter on the other half of the filter.
11. Which of the following are devices used to measure sampling flow rates of high
volume samplers?
a. orifice/pressure indicators
b. mass flowmeters
c. Roots meters
d. a and b, above
e. a, b, and c, above
12. In the calibration set-up for the high volume sampler flow rate transfer stan-
dard depicted below, a, b, c, d, and e are the (?) respectively.
a. water manometer, mercury
manometer, flow rate transfer
standard, Roots meter, and
high volume motor
b. mercury manometer, water
manometer, flow rate transfer
standard, Roots meter, and
high volume motor
c. mercury manometer, water
manometer, high volume
motor, Roots meter, and
flow rate transfer standard
d. water manometer, mercury
manometer, flow rate transfer
standard, high volume motor,
and Roots meter
4-4
-------
13. The U.S. EPA high volume sampling procedure requires that high volume
samplers be operated at sampling flow rates of (?) to (?)
mVmin.
a. 1.0, 2.0
b. 1.1, 1.7
c. 1.0, 1.5
14. A calibration curve for a high volume sampler flow rate transfer standard is
constructed by plotting (?) versus (?)
a. standard flow rate, VI(P«/PJ,-)(298/T,)
b. flow rate transfer standard pressure drop, Roots meter pressure drop
c. standard flow rate, V^H(P1/PB<,)(298/T1)
d. standard flow rate, indicated flow rate
15. Which of the following items is(are) needed to calibrate a high volume
sampler's flow rate measuring device?
a. rotameter
b. elutriator
c. mass flow controller
d. flow rate transfer standard
e. both a and b, above
f. all of the above
16. Which of the following equations is used to correct air volumes measured by
positive-displacement standard volume meters to standard air volumes for the
calibration of high volume sampler flow rate transfer standards?
A V V /P'~AP\ /"M
d. Vad = Vm I— 1 I —I
\ P«d I \ 11 /
Where: V^ = standard volume, std m3
Vm = actual volume measured by the standard volume meter
P! = barometric pressure during calibration, mm Hg or kPa
AP = pressure drop at inlet to volume meter, mm Hg or kPa
Pad= 760 mm Hg or 101 kPa
= ambient temperature during calibration, K
4-5
-------
17. A calibration curve for a high volume sampler is constructed by plotting
(?) versus (?) .
a. standard flow rates, appropriately expressed flow rates indicated by the high
volume sampler's flow rate measuring device
b. flow rate transfer standard pressure drops, appropriately expressed flow
rates indicated by the high volume sampler's flow rate measuring device
c. standard flow rates, flow rate transfer standard pressure drops
18. Which of the following is a(are) potential source(s) of error in high volume
sampling?
a. nonuniform flow rate changes during sampling
b. wind directional sensitivity caused by the gabled roof of the high volume
sampler's shelter
c. artifact paniculate matter formation on alkaline high volume filters
d. all of the above
19. Which of the following devices can minimize errors caused by nonuniform
changes in high volume sampler flow rates during sampling?
a. pressure transducer with continuous recorder for flow rate
b. constant flow rate controllers
c. both a and b, above
d. none of the above
20. True or False? A Reference Flow (ReF) device can be used to audit the flow
rate calibrations of high volume samplers.
21. True or False? Mass flow controllers maintain a constant high volume sampler
flow rate by adjusting the speed of the high volume sampler's motor during
sampling.
22. True or False? Slightly increasing the line voltage to a high volume sampler's
motor will increase motor brush life.
23. Which of the following components of a high volume sampler does not need
periodic cleaning or replacement?
a. flow rate measuring device
b. tubing used in flow-rate indication
c. faceplate gasket
d. motor gaskets
e. none of the above
24. Under the conditions described below, the suspended paniculate concentration
obtained using a high volume sampler is (?) /ig/std m3.
a. 107
b. 94
c. 100 Given: Weight of filter after sampling: 3.216 g
d. 6 Weight of filter before sampling: 3.000 g
Initial sampling flow rate: 1.60 std mVmin
Final sampling flow rate: 1.40 std mVmin
Sampling period: midnight 7-11-81 to midnight 7-12-81
4-6
-------
25. True or False? A high volume sampler is used in the reference method for total
suspended paniculate matter (TSP).
26. True or False? The shelter of a high volume sampler prevents particles that are
greater than 5 /on in diameter from being collected by the sampler.
27. True or False? Motor brushes of a high volume sampler must be periodically
replaced.
28. A high volume sampler should be recalibrated after which of the following?
a. replacement of the paniculate matter filter
b. replacement of the sampler's motor
c. replacement of the sampler motor's brushes
d. both a and b, above
e. both b and c, above
29. Which of the following is the proper sequence of activities for preparing a high
volume paniculate filter for sampling?
a. visually inspect the filter, number the filter, equilibrate the filter, weigh the
filter
b. number the filter, visually inspect the filter, weigh the filter, equilibrate the
filter
c. number the filter, visually inspect the filter, equilibrate the filter, weigh the
filter
d. number the filter, equilibrate the filter, weigh the filter, visually inspect the
filter
30. High volume paniculate filters must be weighed to the nearest (?) mg.
a. 1
b. 10
c. 0.1
31. True or False? Filter cartridges can be used to eliminate the handling of high
volume paniculate filters at sampling sites.
32. Which of the following sampling data must be recorded at the total suspended
paniculate matter (TSP) sampling site?
a. identification of paniculate-matter filter and sampling site
b. initial and final sampler flow rates
c. initial weight of the paniculate filter
d. both a and b, above
e. all of the above
33. True or False? Exposed paniculate filters must be re-equilibrated before they
are weighed.
4-7
-------
34. A high volume particulate-matter filter can be analyzed for which of the
following?
a. organic compounds
b. trace metals
c. all of the above
35. True or False? A variable resistance orifice does not require a set of resistance
plates for the calibration of high volume sampler flow rates.
36. True or False? Before a flow rate transfer standard is calibrated, its calibration
set-up must be checked for air leaks.
37. True or False? The precision of high volume sampling data can be determined
by using collocated high volume samplers.
38. Performance audits should be conducted for which of the following activities of
the reference method for total suspended paniculate matter?
a. filter weighing
b. sampler flow rate calibration
c. data processing
d. a and b, above
e. a, b, and c, above
39. Which of the following should be determined during a systems audit of a total
suspended paniculate matter (TSP) monitoring network?
a. types of high volume samplers and particulate-matter filters used
b. sampling, analysis, data processing, and calibration procedures used
c. whether there is sufficient documentation of TSP monitoring activities
d. b and c, above
e. a, b, and c, above
4-8
-------
Section 4
Review Exercise Answers
Page(s) of Analytical Methods
for Air Quality Standards:
Student Manual
1. d 5-1
2. d 5-2
3. True 5-4
4. e 5-4
5. c 5-4
6. True 5-4
7. d 5-4,5-5
8. True 5-7
9. True 5-8
10. False 5-8
11. d 5-9
12. b 5-11
13. b 5-19
14. c 5-14,5-15
15. d 5-14,5-15
16. d 5-13,5-14
17. a 5-16,5-17
18. d 5-22, 5-23, 5-25
19. c 5-22,5-23
20. True 5-27
21. True 5-22
22. False 5-26
23. e 5-26, 5-27
24. c 5-20,5-21
25. True 5-1, 5-2
26. False 5-2
27. True 5-26
28. e 5-26
29. c 5-18
30. a 5-18
31. True 5-18
32. d 5-9
33. True 5-19
34. c 5-4
35. True 5-12, 5-13
36. True 5-12
37. True 5-25
38. e 5-27
39. e 5-29
4-9
-------
Section 5
Reference Methods
for Carbon Monoxide
Reading Assignment
Pages 6-1 through 6-15 of EPA 450/2-81-018b, APTI Course 464 Analytical
Methods for Air Quality Standards: Student Manual.
Reading Assignment Topics
Reference measurement principle
Description of a Luft-type carbon monoxide analyzer
Calibration of carbon monoxide analyzers
Interferences
Description of a gas-filter correlation carbon monoxide analyzer
Maintenance and troubleshooting of carbon monoxide analyzers
Quality assurance for carbon monoxide analyzers
Learning Goal and Objectives
Learning Goal
The purpose of this section is to familiarize you with reference methods for
monitoring carbon monoxide.
Learning Objectives
At the end of this section, you should be able to—
1. describe the carbon monoxide reference measurement principle,
2. describe typical nondispersive infrared (NDIR) carbon monoxide analyzers,
3. describe the calibration of carbon monoxide analyzers,
4. identify at least two potential interferences associated with NDIR carbon
monoxide analyzers and at least three methods for their removal,
5. describe maintenance and troubleshooting procedures for NDIR carbon
monoxide analyzers,
6. recognize at least three parameters associated with carbon monoxide
analyzers that require quality control, and
7. describe a water vapor interference check for carbon monoxide analyzers.
5-1
-------
Reading Guidance
• Refer often to the tables and figures of the assigned reading material as you
progress through the assignment.
• When you have finished the reading assignment, complete the review exercise
for Section 5. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), proceed to Section 6
of this guidebook.
5-2
-------
Review Exercise
Now that you've completed the assignment for Section 5, please answer the follow-
ing questions. These will help you determine whether you are mastering the
material.
1. The carbon monoxide reference measurement principle uses (?)
a. absorption of ultraviolet radiation
b. absorption of infrared radiation
c. flame photometry
d. gas-phase chemiluminescence
2. True or False? Carbon monoxide analyzers use diffraction gratings to isolate a
specific infrared wavelength for absorption by carbon monoxide.
For each of questions 3 through 9, match the analyzer component with its
appropriate figure in the diagram of a typical Luft-type nondispersive infrared
(NDIR) carbon monoxide analyzer shown below.
3. infrared source
4. beam chopper
5. bandpass filter
6. sample cell
7. detector
8. reference cell
9. diaphragm
5-3
-------
10. A(n) (?) is usually used as the source of infrared radiation in an
NDIR carbon monoxide analyzer.
a. infrared lamp
b. photomultiplier tube
c. tungsten lamp
d. heated wire
11. True or False? The beam chopper of an NDIR carbon monoxide analyzer
helps amplify the analyzer detector's output.
12. Infrared radiation emerging from the sample cell of a Luft-type NDIR carbon
monoxide analyzer should always be (?) the infrared radiation
emerging from the analyzer's reference cell.
a. less than
b. greater than
c. equal to
d. less than or equal to
e. greater than or equal to
13. The detector cell of a Luft-type NDIR carbon monoxide analyzer consists of
(?) compartments filled with equal concentrations of (?)
a. 3, carbon monoxide
b. 2, carbon monoxide
c. 3, nitrogen
d. 2, nitrogen
14. True or False? The detector compartments of a Luft-type NDIR carbon
monoxide analyzer are separated by an immovable diaphragm.
15. True or False? When carbon monoxide is present in the sample cell of a Luft-
type NDIR carbon monoxide analyzer, the analyzer's diaphragm bends into the
sample compartment of the analyzer's detector.
16. True or False? In calibrating an NDIR carbon monoxide analyzer, calibration
gases should be introduced through the analyzer's sampling line.
17. Which of the following is a(are) component(s) of a gas-filter correlation NDIR
CO analyzer?
a. gas cell wheel
b. sample chamber
c. reference cell
d. a and b, above
e. a, b, and c, above
18. True or False? Carbon monoxide cylinder gases should consist of carbon
monoxide and dry nitrogen if they are to be diluted less than 100:1 with air
when preparing carbon monoxide calibration gases.
19. True or False? The gas-filter correlation technique greatly reduces interference
effects associated with NDIR CO analyzers.
5-4
-------
20. True or False? Water vapor and carbon dioxide are potential negative
interferences in the NDIR measurement of carbon monoxide.
21. Which of the following can be used to minimize both water vapor and carbon
dioxide interferences in the NDIR measurement of carbon monoxide?
a. silica gel
b. refrigeration units
c. negative filtering
d. interference cells
e. both a and b, above
f. both c and d, above
22. (?) fluctuations can cause changes in the response of an NDIR
carbon monoxide analyzer.
a. Temperature
b. Pressure
c. Temperature and pressure
d. none of the above
23. True or False? Sampling flow rate fluctuations can cause changes in the
response of an NDIR carbon monoxide analyzer.
24. True or False? Paniculate matter must be removed from sample air before the
sample air enters the sample cell of an NDIR carbon monoxide analyzer.
25. True or False? All Luft-type NDIR carbon monoxide analyzers are insensitive
to mechanical vibration.
26. Which of the following components of an NDIR carbon monoxide analyzer
should be periodically checked?
a. vacuum pump
b. infrared radiation source(s)
c. optical system
d. b and c, above
e. a, b, and c, above
27. Which of the following are possible causes for a Luft-type carbon monoxide
analyzer to yield erroneously high carbon monoxide concentrations?
a. reference infrared radiation source failing
b. sample infrared radiation source failing
c. decreased pressure in reference compartment of detector
d. decreased pressure in sample compartment of detector
e. both a and c, above
f. both b and d, above
5-5
-------
28. Which of the following are possible causes for a Luft-type carbon monoxide
analyzer to yield erroneously low carbon monoxide concentrations?
a. reference infrared radiation source failing
b. sample infrared radiation source failing
c. decreased pressure in reference compartment of detector
d. decreased pressure in sample compartment of detector
e. both a and c, above
f. both b and d, above
29. If a water vapor interference check of an NDIR carbon monoxide analyzer
results in a difference between dry and saturated values of (?) ppm
or greater, the analyzer's water vapor removal system must be repaired or
replaced.
a. 0.1
b. 0.5
c. 1.0
d. 2.0
30. Which of the following operating parameters of an NDIR carbon monoxide
analyzer should be routinely checked?
a. zero drift
b. span drift
c. sample cell pressure
d. a and b, above
e. a, b, and c, above
5-6
-------
Section 5
Review Exercise Answers
Page(s) of Analytical Methods
for Air Quality Standards:
Student Manual
1. b 6-1
2. False 6-1
3. a 6-3
4. c 6-3
5. b 6-3
6. e 6-3
7. f 6-3
8. d 6-3
9. g 6-3
10. d 6-3
11. True 6-3
12. d 6-3
13. b 6-3
14. False 6-4
15. True 6-4
16. True 6-5
17. d 6-10
18. False 6-5
19. True 6-10
20. False 6-6, 6-7
21. f 6-6, 6-7
22. c 6-12
23. True 6-12
24. True 6-12
25. False 6-12
26. e 6-13
27. f 6-14
28. e 6-14
29. b 6-14
30. e 6-15
5-7
-------
Section 6
Reference Methods
for Nitrogen Dioxide
Reading Assignment
Pages 7-1 through 7-14 of EPA 450/2-81-018b APTI Course 464 Analytical
Methods for Air Quality Standards: Student Manual.
Reading Assignment Topics
Reference measurement principle
Description of typical nitrogen dioxide analyzers
Calibration of nitrogen dioxide analyzers
Interferences
Maintenance and troubleshooting of nitrogen dioxide analyzers
Quality assurance for nitrogen dioxide analyzers
Learning Goal and Objectives
Learning Goal
The purpose of this section is to familiarize you with reference methods for
monitoring nitrogen dioxide.
Learning Objectives
At the end of this section, you should be able to—
1. describe the nitrogen dioxide reference measurement principle,
2. describe typical chemiluminescent nitrogen dioxide analyzers,
3. describe the gas phase titration (GPT) and permeation tube methods of
calibrating nitrogen dioxide analyzers,
4. identify at least two potential interferences associated with chemiluminescent
nitrogen dioxide analyzers,
5. describe maintenance and troubleshooting procedures for chemiluminescent
nitrogen dioxide analyzers,
6. recognize at least four components of a nitrogen dioxide measurement system
that require visual inspection, and
7. recognize two types of performance audits for nitrogen dioxide analyzers.
6-1
-------
Reading Guidance
• Refer often to the table and figures of the assigned reading material as you
progress through the assignment.
• When you have finished the reading assignment, complete the review exercise
for Section 6. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), take Quiz 2. Follow
the directions listed in the Course Introduction section of this guidebook.
• After completing Quiz 2, proceed to Section 7 of this guidebook.
6-2
-------
Review Exercise
Now that you've completed the assignment for Section 6, please answer the follow-
ing questions. These will help you determine whether you are mastering the
material.
1 . The reference measurement principle for nitrogen dioxide (NO2) employs
a. gas-phase chemiluminescence
b. flame photometry
c. nondispersive infrared spectroscopy
d. ultraviolet photometry
2. In the NO2 reference measurement principle, light is emitted as a result of
(?) reacting with (?)
a NOj, ozone (Os)
b. NO, ozone
c. NO,, NO
d. NO, oxygen (O2)
3. True or False? NO* is measured directly by NO2 analyzers.
4. True or False? NO2 must be converted to NO before it can be measured by
NO2 analyzers.
5. Which of the following equations describes the chemiluminescent reaction of
the NO2 reference measurement principle?
a. NO2 + O,-NO*
NO* -NO -Hi?
b. NO + OS-NO2*
NO2*-NO2 + h»>
c.
d. NO + 2O2-NO2*
6. Cyclic chemiluminescent NO2 analyzers have (?) reaction chamber(s)
and (?) detector(s).
a. 1, 1
b. 1,2
c. 2, 1
7. True or False? In a dual chamber chemiluminescent NO2 analyzer, sample air
flows continuously through a converter.
6-3
-------
8. True or False? Varying concentrations of ozone are supplied to the reaction
chamber of a chemiluminescent NO2 analyzer by an internal ozone generator.
9. The reaction chamber of a chemiluminescent NO2 analyzer is maintained
(?) atmospheric pressure.
a. at
b. below
c. above
10. An optical filter is placed between the reaction chamber and photomultiplier
tube of a chemiluminescent NO2 analyzer to eliminate interfering emissions
caused by the reaction of ozone with (?)
a. NO2
b. NO
c. NO2*
do unsaturated hydrocarbons
11. True or False? Heating the photomultiplier tube (PMT) of a chemiluminescent
NO2 analyzer increases its sensitivity.
12. Which of the following is a(are) method(s) allowed by U.S. EPA for the
calibration of an NO2 analyzer?
a. gas phase titration
b. NO2 permeation tube/dilution system
c. ultraviolet photometry
d. both a and b, above
e. both b and c, above
13. Which of the following must be calibrated during the calibration of an NO2
analyzer?
a. analyzer's NO2 response
b. analyzer's NO response
c. analyzer's NO* response
d. a and b, above
e. a, b, and c, above
14. In the gas phase titration calibration of an NO2 analyzer, (?) is added
to excess (?) in a dynamic calibration system to generate known
concentrations of NO2.
a. NO, ozone
b. ozone, NO
c. NO, N02
d. NO2, NO
15. A gas phase titration system that is used to calibrate an NO2 analyzer must
have a dynamic parameter specification equal to or greater than
(?) ppm-minutes.
a. 1.00
b. 2.00
c. 2.75
d. 3.75
6-4
-------
16. Cylinder gas used in the calibration of an NO* analyzer must consist of NO
and (?) having an NO2 impurity of less than (?) ppm.
a. nitrogen, 2
b. air, 2
c. oxygen, 1
d. nitrogen, 1
17. True or False? In a gas-phase titration calibration system for an NO2 analyzer,
the mixing chamber must be downstream of the reaction chamber.
18. True or False? Flushing a gas-phase titration system with NO before it is used
to calibrate an NO* analyzer assures that there is no NO* present at the begin-
ning of the calibration.
19. True or False? In a gas-phase titration calibration of an NO2 analyzer, the
analyzer's NO response must be calibrated before its NO2 response.
20. An NO2 analyzer must have an average converter efficiency of (?)
percent or greater.
a. 26
b. 56
c. 76
d. 96
21. True or False? An NO, permeation tube consists of a tube that is partially
filled with liquefied NO,. The gaseous NO2 above the liquid is able to
permeate the walls of the tube.
22. True or False? Purge gas passing over a permeation tube in an NO2
permeation tube/dilution system used to calibrate an NO2 analyzer does not
have to be maintained at a constant temperature.
23. True or False? If an NO2 analyzer is calibrated by using an NO2
permeation tube/dilution system, its converter efficiency does not have to be
determined.
24. Which of the following is a(are) potential interference(s) in the gas-phase
chemiluminescent measurement of NO2?
a. PAN
b. organic nitrates
c. organic nitrites
d. a and b, above
e. a, b, and c, above
25. True or False? Chemical converters of NO2 analyzers never have to be replaced
or reactivated.
26. Ammonia is oxidized to NO by NO2 analyzer thermal converters operating at
temperatures of (?) °C or greater.
a. 100
b. 250
c. 350
d. 600
6-5
-------
27. An NO2 analyzer that has an ineffective NO2 converter will yield erroneously
low (?) concentrations.
a. NO
b. NO,
c. N02
d. both a and b, above
e. both b and c, above
28. Which of the following operating parameters of an NO2 monitoring system
should be routinely checked?
a. temperature of monitoring shelter
b. sample-air introduction system
c. operation of NO2 analyzer/recording system
d. b and c, above
e. a, b, and c, above
29. Performance audits should be conducted for which of the following activities of
the gas-phase chemiluminescent measurement of NO2?
a. NO2 analyzer multipoint calibration
b. NO2 data reduction
c. both a and b, above
6-6
-------
Section 6
Review Exercise Answers
Page(s) of Analytical Methods
for Air Quality Standards:
Student Manual
1. a 7-1
2. b 7-1
3. False 7-1
4. True 7-1
5. b 7-2
6. a 7-3
7. True 7-3
8. False 7-2
9. b 7-5
10. d 7-5
11. False 7-5
12. d 7-6
13. e 7-6
14. b 7-6
15. c 7-7
16. d 7-7
17. True 7-7
18. True 7-7
19. True 7-7, 7-8
20. d 7-8
21. True 7-9
22. False 7-10
23. False 7-11
24. e 7-11
25. False 7-4
26. d 7-4
27. e 7-2, 7-13
28. e 7-13, 7-14
29. c 7-14
6-7
-------
Section 7
Reference Method for Lead
Reading Assignment
Pages 7-3 through 7-42 of this guidebook.
Reading Assignment Topics
General description of the reference method
Sample analysis
Calculations and data reporting
Maintenance and troubleshooting
Auditing
Learning Goal and Objectives
Learning Goal
The purpose of this section is to familiarize you with the reference method for
measuring lead.
Learning Objectives
At the end of this section, you should be able to—
1. recognize the use of a high volume sampler in the lead reference method,
2. describe minimum specifications for equipment and reagents used in the
analysis of lead,
3. identify two sample extraction procedures and recognize critical steps in sam-
ple extraction,
4. recognize at least two important considerations for sample analysis using an
atomic absorption spectrophotometer,
5. describe the calibration of an atomic absorption spectrophotometer,
6. calculate lead concentration from sampling and analysis data,
7. describe maintenance and troubleshooting procedures for an atomic
absorption spectrophotometer,
8. describe performance audits for high volume sampler flow rate, lead analysis,
and data processing, and
9. recognize at least three items that should be checked during a system audit for
the lead reference method.
7-1
-------
Reading Guidance
9 Because the lead reference method uses the high volume sampler method
(described in Section 4 of this guidebook) for sample collection, this section
deals mainly with lead analysis.
• The first word in the 13th line of Section 6.1 of the reading assignment should
be "more" not "less."
• Refer often to the equations, tables, and figures of the assigned reading
material as you progress through the assignment.
• When you have finished the reading assignment, complete the review exercise
for Section 7. It begins on page 7-43.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), proceed to Section 8
of this guidebook.
7-2
-------
Excerpts of Section 2.8 of
Quality Assurance Handbook for
Air Pollution Measurement Systems,
Volume II EPA 600/4-77-027a
Section 2.8
REFERENCE METHOD FOR THE DETERMINATION OF LEAD IN
SUSPENDED PARTICULATE MATTER COLLECTED FROM
AMBIENT AIR
7-3
-------
Section No. 2.8
Revision No. 0
Date December 30, 1981
Page 2 of 5
SUMMARY
Ambient air is drawn through a glass fiber filter of a
hi-vol sampler to collect particulate material. The lead con-
centration in the suspended particulate matter is analyzed by
atomic absorption spectrophotometry.*
This method of sampling is applicable to measurement of the
mass concentration of suspended particulates in ambient air.
The size of the sample collected is usually adequate for other
analyses. When the sampler is operated 24 h at an average flow
rate of 1.70 m3/min (60.0 ft3/min) an adequate sample is ob-
tained, even in an atmosphere having a concentration of sus-
pended particulates as low as 1 pg/m3.
The typical range of the method is 0.07 to 7.5 |jg Pb/m3
assuming an upper linear range of analysis of 15 ng/ml and an
air volume of 2400 m3. Typical sensitivities for a 1% change in
absorption (0.0044 absorbance units) are 0.2 and 0.5 pg Pb/ml
for the 217.0 and 283.3 nm lines, respectively. A typical lower
detectable limit (LDL) is 0.07 pg Pb/m3 when an air volume of
2400 m3 is assumed. The value quoted in the Federal Register1
(0.07 (jg Pb/m3) was derived from instruments of different models
using the 283.3 and the 217.0 nm Pb lines.
Absolute values for individual laboratories will vary with
the type of instrument, the absorption wavelength, and the in-
strumental operating conditions.
The method description which follows is based on the pro-
mulgated Reference Method.1
7-4
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Section No. 2.8.2
Revision No. 0
Date December 30, 1981
Page 2 of 4
2.2 Atomic Absorption Spectrophotometer
Major repairs and adjustment of the atomic absorption spec-
trophotomster normally require the services of the manufacturer
or the manufacturer's representative. However, before operating
the spectrophotometer, instrument performance, such as sensitivi-
ty and reproducibility should be checked by using a standard
metal solution. The instrument sensitivity- depends on various
factors such as alignment of the hollow cathode lamp and burner
head, cleanness of optical systems and burner head, and the level
of grating system calibration. An optimal sensitivity is recom-
mended by the manufacturer in the instrument manual. After this
sensitivity is achieved, check the reproducibility. Typical
sensitivities for a 1% change in absorption are 0.2 and 0.5 |jg
Pb/ml for wavelengths of 217.0 and 283.3 nm, respectively. An
instrument reproducibility change of ±5% is acceptable; repeat
the analysis until this limit is achieved. If the reproducibili-
ty varies by more than ±5%, the instrument should be checked by a
manufacturer's representative or a qualified operator.
The following step-by-step reproducibility test procedure is
recomended:
1. Prepare a series of standard lead solutions containing
0.2, 1.6, and 10.0 |jg Pb/ml, or 3 standard concentrations that
"bracket" the normal sample concentration range, as described in
Section 2.8.5, Subsection 5.7.2.
2. Set the atomic absorption spectrophotometer for stan-
dard conditions, as described in Section 2.8.5, Subsection 5.6.
3. Take three or more readings for each standard metal
solution prepared in step 1. This can be done either sequential-
ly or by alternating the standards, however, calibration stan-
dards should be analyzed at random throughout the analysis to
check the calibration stability. See Section 2.8.5, Subsection
5.7.3.
4. Record the instrument response in absorbance units. if
using a strip chart recorder, take the mid point of the noise as
baseline and measure the net difference between the baseline
7-5
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Section No. 2.8.2
Revision No. 0
Date December 30, 1981
Page 3 of 4
noise and the peak height. If the instrument has a digital read-
out and printer, there is no need to manually measure peaks and
absorbance units can be read directly.
5. Determine the instrument's reproducibility by subtract-
ing the lowest response from the highest response, then dividing
by average response, and multiplying by 100. Correct these
values by subtracting the blank. For example, assume that the
three response values derived from a 10.0 pg Pb/ml standard
solution are:
Absorbance Peak response minus blank
Blank = 0.005
1st peak = 0.100 0.095
2nd peak = 0.098 0.093
3rd peak = 0.098 0.093
The average response value for these three analyses is
0.094, which represents the standard metal solution's concen-
tration (10.0 pg Pb/ml). The maximum percentage absorbance
fluctuation is given by:
Percent fluctuation = 10° * ^ °'°93) = 2%.
The percent fluctuation should be <_5%; if not, have the instru-
ment checked by a qualified service engineer.
7-6
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 1 of 14
5.0 ANALYSIS OF SAMPLES
Table 5.1 at the end of this section summarizes the major
quality assurance activities for sample analyses.
5.2 General Analysis Description
In atomic absorption spectrophotometry, the element being
measured is aspirated into a flame or injected into a carbon arc
furnace and atomized. A light beam is directed through the
flame, into a monochromator, and onto a detector that measures
the amount of light absorbed by the atomized element.
Because each metallic element has its own characteristic
absorption wavelength, a source lamp composed of that specific
element is used to minimize spectral or radiation interferences.
The amount of absorption of the characteristic wavelength is
proportional to the concentration of the element in the sample.
With the EPA method, at least two types of interferences
are possible: chemical and light scattering.3'4'5'6'7 Reports
on the absence of chemical interference far outnumber reports on
its presence; therefore, no correction for chemical interference
is given here. Non-atomic absorption as light scattering,
produced by high concentrations of dissolved solids in the sam-
ple, can produce a significant interference, especially at low
lead concentrations. The interference is greater at the
217.0-nm wavelength than at the 283.3-nm wavelength; in fact,
Scott, D.R., et al. have reported that no interference was
observed using the 283.3-nm wavelength.3
In this type of photometric analysis, the concentration of
the sample and particularly the concentration of reagent and
standard solutions, are of utmost importance to the accuracy of
the determination. Samples and standard metal solutions must be
carefully and accurately prepared.
7-7
-------
Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 2 of 14
5.3 Apparatus
5.3.1 Atomic Absorption Spectrophotometer - An atomic absorp-
tion spectrophotometer is required for determination of lead
content in suspended particulate matter, and must be equipped
with a lead hollow cathode lamp or electrodeless discharge lamp.
5.3.2 Acetylene - The grade recommended by the instrument manu-
facturer should be used as a fuel. Change cylinder when pres-
sure drops below 50 - 100 psig.
5.3.3 Air - Filtered clean air (as free of particulates, oil
and water as possible) is needed as an oxidant.
7-8
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 3 of 14
5.3.4 Glassware -
a. Beaker - Beakers, Borosilicate glass, including 30 ml
and 150 ml are needed to digest the sample. Phillips beakers
are useful for this purpose.
b. Volumetric flask - 100-ml volumetric flasks (Class A)
are required for analysis.
c. Pipette - Several volumetric pipettes (Class A), in-
cluding 1, 2, 4, 8, 15, 30, 50 ml should be available for the
analysis.
All glassware should be thoroughly cleaned with laboratory
detergent, rinsed, soaked for 4 h in 20% (w/w) HNO3, rinsed 3
times with distilled deionized water, and dried in a dust free
manner.
5.3.5 Hot plate - Hot plates, 750 watts, 120 volt, having
enough plate surface area for several sample beakers, and cap-
able of heating to 370°C (698°F) are required for the hot ex-
traction of the sample.
5.3.6 Ultrasonication Bath Unheated - An ultrasonication bath
is required for the sample extraction when an ultrasonic extrac-
tion procedure is employed, and should provide the necessary
energy (>20,000 cycles per second). Commercially available
baths of 450 watts or higher cleaning power have been found
satisfactory.
5.3.7 Template - Templates are needed to aid in sectioning the
glass fiber filter (Figure 5.1).
5.3.8 Pizza Cutter - A pizza cutter having a thin wheel (<1 mm
thickness) is needed to cut the filter. (Figure 5.2).
5.3.9 Watch glass - A watch glass is needed to cover the beaker
containing the sample.
5.3.10 Polyethylene Bottle - Linear polyethylene bottles are
needed to store the samples for subsequent analysis.
7-9
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 4 of 14
30 cm
MANILA FOLDER - TO PREVENT
FILTER FROM STICKING TO
PLASTIC
GLASS FIBER FILTER FOLDED
(LENGTHWISE) IN HALF
12,7
WIDTH OF GROOVE/
1 cm ~77
ALL GROOVES
2 mm DEEP
L-JUGID PLASTIC
25 mm
(Tin.) WIDE
0.8 cm
IZZA CUTTER
IDTH OF GROOVE 8 mm
Figure 5.1. Sample preparation, filter sectioning 1.
7-10
-------
Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 5 of 14
STRIP FOR
OTHER ANALYSES
19'mm * 203 m
LEAD ANALYSIS
Figure 5.2. Sample preparation, filter sectioning 2.
7-11
-------
Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 6 of 14
5.3.11 Parafilm M Sealing Film - A pliable, selfsealing, mois-
ture proof, thermoplastic sheet material, substantially color-
less is recommended for use in sealing the acidified sample
beakers. Commercially available Parafilm M satisfies this
requirement.
5.4 Reagents (Analysis)
5.4.1 Nitric Acid (HNO^) Concentrated - A.C.S. reagent grade
HNO3 and commercially available redistilled HNO3 have been found
to have sufficiently low lead concentration.
5.4.2 Hydrochloric Acid (HC1) Concentrated - A.C.S. reagent
grade.
5.4.3 Water - The same source or batch of distilled deionized
water must be used for all purposes in the analysis.
5.4.4 3M HNOs - This solution is used in the hot extraction
procedure. To prepare, add 192 ml of concentrated HN03 to dis-
tilled deionized water in a 1-2 volumetric flask. Shake well,
cool, and dilute to volume with distilled deionized water. Cau-
tion: Nitric acid fumes are toxic. Prepare in a well venti-
lated fume hood.
5.4.5. Glass Fiber Filter - Low lead content of the filter is
desirable. EPA typically obtains filters with a lead content of
<75 pg/filter. Minimal variation in lead content from filter to
filter is also important.
5.4.6 0.45M HNC-3 - This solution is used as the matrix for
calibration standards when using the hot extraction procedure.
To prepare, add 29 ml of concentrated HNO3 to distilled deion-
ized water in a 1-2 volumetric flask. Shake well, cool, and
dilute to volume with distilled deionized water.
5.4.7 2.6M HNOa + (0 to 0. 9M HCl) - This, solution is used in
the ultrasonic extraction procedure and the concentration of HCl
can be varied from 0 to 0.9M. Directions for preparing a 2. 6M
7-12
-------
Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 7 of 14
HN03 + 0.9M HCl solution are as follows: place 167 ml of concen-
trated HNO3 into a l-£ volumetric flask and add 77 ml of concen-
trated HC1. Stir 4 to 6 h, dilute to nearly 1 £ with distilled
deionized water, cool to room temperature, and dilute to 1
liter.
5.4.8 0.40M HNOa + xM HCl - This solution is used as the matrix
for calibration standards when using the ultrasonic extraction
procedure. To prepare, add 26 ml of concentrated HNO3, plus the
ml of HCl required (Equation 5-1), to a l-£ volumetric flask.
Dilute to nearly 1 SL with distilled deionized water, cool to
room temperature, and dilute to 1 £. The amount of HCl required
can be determined from the following equation:
y = <77 m^.|V5) * Equation 5-1
where
y = ml of concentrated HCl required,
x = molarity of HCl from Subsection 5.4.7, and
0.15 = dilution factor from Subsection 5.5.2.
5.4.9 Lead Nitrate Pb(NQg)g - A.C.S. reagent grade purity of
99.0%. Heat for 6 h at 120°C and cool in a desiccator.
5.4.10 Stock Lead Solution (1000 pg Pb/ml) in HNOs - Dissolve
1.598 g of Pb(NO3)2 in 0.45M HNO3 contained in a l-£ volumetric
flask and dilute to volume with 0.45M HN03.
5.4.11 Stock Lead Solution (1000 ug Pb/ml) in (HNO.,/HC1) - Pre-
pare as in 5.4.10 except use the HNO3/HC1 solution from 5.4.8.
Store standard in a linear polyethylene bottle. Commer-
cially available certified lead standard solutions may be used.
This stock solution may be stored up to 2 years. Label clearly
with contents, concentration, person who prepared the standard,
date prepared and expiration date. This date should be periodi-
cally checked and a fresh standard made as required.
7-13
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 8 of 14
5.5 Sample Preparation for Atomic Absorption Spectrophotometry
5.5.1 Hot Extraction Procedure -
1. Cut a 1.9 cm x 20.3 cm (3/4 in. x 8 in.) strip from
the exposed filter using a template and a pizza cutter as de-
scribed in Figures 5.1 and 5.2. Other cutting procedures may be
used. Care should be taken to avoid cross-contamination from
one filter to another by wiping off any fibers which may adhere
to template or pizza cutter between samples. Note; Lead in
ambient particulate matter collected on glass fiber filters has
been shown to be uniformly distributed across the filter.3'5'8
Another study9 has shown that when sampling near a roadway,
strip position contributes significantly to the overall varia-
bility associated with lead analysis. Therefore, when sampling
near a roadway, additional strips should be analyzed to minimize
this variability-
2. Fold the sample in half twice and place in a 150-ml
beaker. Add 15 ml of 3M HNO3 to completely cover the sample.
Cover the beaker with a watch glass. It is important to keep
the sample covered so that corrosion products (formed on fume
hood surface which may contain lead) are not deposited in the
extract.
3. Gently boil the sample in a beaker on a hot plate
under a fume hood for 30 min. Do not let the sample evaporate
to dryness. Caution: Nitric acid fumes are toxic.
4. After 30 min, remove the beaker from the hot plate and
cool to near room temperature. Rinse watch glass and sides of
beaker with distilled deionized water.
5. Decant extract and rinsings into a 100-ml volumetric
flask, and add distilled deionized water to 40 ml mark on
beaker, cover with watch glass, and set aside for a minimum of
30 min. This is a critical step and cannot be omitted since it
allows the HN03 trapped in the filter to diffuse into the rinse
water.
7-14
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 9 of 14
6. Decant the water from the filter into the volumetric
flask and rinse filter and beaker twice with distilled deionized
water and add rinsings to volumetric flask until total volume is
80 to 85 ml.
7. Stopper flask and shake vigorously, and set aside for
approximately 5 min or until foam has dissipated.
8. Bring solution to volume with distilled deionized
water and mix thoroughly. Allow solution to settle for one hour
before proceeding with analysis. (Note; Do not filter the
extracted sample to remove particulate matter because of loss of
lead due to filtration. The final extract can be centrifuged at
2000 RPM for 30 min to remove any suspended solids.
9. If sample is to be stored for subsequent analysis,
transfer to a linear polyethylene bottle, being careful not to
disturb the settled solids.
5.5.2 Ultrasonic Extraction Procedure -
1. Cut a 1.9 cm x 20.3 cm (3/4 in. x 8 in.) strip, as de-
scribed in Subsection 5.5.1, step 1.
2. Fold the sample in half twice and place in a 30-ml
beaker. Add 15 ml of HN03/HC1 solution (see Subsection 5.4.7)
to completely cover the sample, and cover the beaker with
Parafilm. The Parafilm should be placed over the beaker such
that none of the Parafilm is in contact with water in the ultra-
sonic bath. Otherwise, rinsing of the Parafilm in step 4 may
contaminate the sample.
3. Place the beaker in the ultrasonication bath and
operate for 30 min.
4. Rinse Parafilm and sides of beaker with distilled
deionized water.
5. Decant the extract and rinsings into a 100-ml volumet-
ric flask. Add 20 ml distilled deionized water to cover the
filter strip, cover with Parafilm, and set aside for a minimum
of 30 min. This is a critical step and cannot be omitted. The
sample is then processed as in Subsection 5.5.1, steps (6)
7-15
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Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 10 of 14
through (9). Samples prepared by hot extraction procedure are
now in 0.45M HNO3 and samples prepared by ultrasonic extraction
procedure are now in 0.40M HNO3 + xM HC1.
5.6 Instrument Operation and Analysis
Because of the differences between makes and models of
atomic absorption spectrophotometers, it is difficult to formu-
late detailed instructions applicable to every instrument. Con-
sequently, it is recommended that the user follow manufacturer's
operating instructions.
1. Set the atomic absorption spectrophotometer for the
standard conditions as follows: choose the correct hollow
cathode lamp or electrodeless discharge lamp for lead, install,
and align in the instrument; position the monochromator at 217.0
nm or 283.3 run; select the proper monochromator slit width; set
the light source current according to the manufacturer's recom-
mendation; light the flame and regulate the flow of fuel and
oxidant; adjust the burner for maximum absorption and stability;
and balance the photometer.
2. If using a chart recorder set the chart speed at 8 cm
to 15 cm per minute and turn on the power, servo, and chart
drive switches. Adjust the chart pen to the 5% division line.
Also adjust instrument span using highest calibration standard.
While aspirating the standard sample, span instrument to desired
response.
3. The sample can be analyzed directly from the volu-
metric flask, or an appropriate amount of sample decanted into a
sample analysis tube. In either case, care should be taken not
to disturb the settled solids. At least the minimum sample
volume required by the instrument should be available for each
aspiration.
4. Aspirate samples, standards, and blank into the flame
and record the absorbance. If using a recorder wait for re-
sponse to stabilize before recording absorbance.
7-16
-------
Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 11 of 14
5. Determine the average absorbance value for each known
concentration, and correct all absorbance values by subtracting
the blank absorbance value. Determine the lead concentration in
|jg Pb/ml from the calibration curve as presented in the follow-
ing subsection. Record these values on the Data Record Form
(Figure 6.1 of Section 2.8.6).
Note;
a. Samples that exceed the calibration range should be
diluted with acid of the same concentration and matrix as the
calibration standards and reanalyzed.
b. Check for drift of the zero point resulting from pos-
sible nebulizer clogging, especially when dealing with samples
of low absorbance.
5.7 Preparation of Calibration Curve
5.7.1 Working Standard Solution (20 |jg Pb/ml) - Prepare by
diluting 2 ml of stock lead solution (Subsection 5.4.10 if the
hot extraction was used or Subsection 5.4.11 if the ultrasonic
extraction procedure was used) to 100 ml with acid of the same
concentration and matrix as used in the stock lead solution.
This standard should be prepared daily.
5.7.2 A Series of Calibration Standards - Prepare daily by
diluting the working standard solution (Subsection 5.7.1) as
indicated below with the same acid matrix as used in the working
solution. Other lead concentrations may be used provided they
are in the linear range of the instrument.
Volume of 20 pg/ml Final Concentration
working standard, ml volume, ml pg Pb/ml
0 100 0.0
1.0 200 0.1
2.0 200 0.2
2.0 100 0.4
4.0 100 0.8
8.0 100 1.6
15.0 100 3.0
30.0 100 6.0
50.0 100 . 10.0
100.0 100 20.0
7-17
-------
Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 12 of 14
5.7.3 Calibration Curve - Since the working range of analysis,
will vary depending on which wavelength is used and the type of
instrument, no one set of instructions for preparation of a
calibration curve can be given.
Select at least three standards (plus the reagent blank) to
cover the linear range indicated by the instrument's manufac-
turer. Aspirate these standards and the blank and measure the
absorbance. Repeat until good agreement is obtained between re-
plicates. Plot absorbance (y-axis) versus concentration in pg
Pb/ml (x-axis) as shown in Figure 5.3. Draw a straight line
through the linear portion of the curve, and do not force the
calibration curve through zero. Note; To determine stability
of the calibration curve, analyze a control standard before the
first sample, after every subsequent 10th sample, and after the
last sample. Vary the control standard concentration by alter-
nating, in run sequence, a value less than 1 |jg Pb/ml, and a
value between 1 and 10 M9 Pb/ml. If either standard deviates by
more than 5% from the value predicted by the calibration curve,
take corrective action and repeat the previous 10 analyses.
7-18
-------
Section No. 2.8.5
Revision No. 0
Date December 30, 1981
Page 13 of 14
i I i i I I I
0.20
0.15
I °-10
to
5
0.05
2 4 6 8 10 12 14 16 18 20
Concentration, ug Pb/ml
Figure 5.3. Example of a calibration curve for absorbance
versus concentration of Pb standard.
7-19
-------
Section No. 2.8.5
Revision No. 0
Date December 30,
Page 14 of 14
1981
TABLE 5.1. ACTIVITY MATRIX FOR ANALYSIS OF SAMPLES
Activity
Acceptance limits
Frequency and method
of measurement
Action IT
requirements
are not met
Verify documen-
tation and
inspect sample
Complete documentation;
absence of evidence of
malfunction or sample
loss; ten or fewer
insects visible in
sample
Visual check
Void sample
Atomic absorp-
tion spectro-
photometer
Equipped with lead
hollow cathode lamp
electrodeless dis-
charge lamp
or
Upon receipt check
for specifications
or certification
Service by
manufacturer
Reagents
All reagents must be
A.C.S. reagent grade
Prepare fresh as
introduced in Sub-
sec 5.4
Use new
reagents
Glassware
Borosilicate glass and
Class A
Upon receipt check
for stock number,
cracks, breaks, and
manufacturer flaws
Replace or
return to
supplier
Filter strip
Size = 1.9 cm x 20.3 cm
(3/4 in. x 8 in.)
Check its size
Prepare new
strip
Hot extraction
Do not evaporate to
dryness and cover so
that corrosion products
are not deposited in
the extract
Frequently and
visually check the
level of evapora-
tion
Void sample
Ultrasonic
extraction
Provide >20,000 cycles
per second
Upon receipt check
the label and per-
formance by comparing
to the hot extraction
procedure
Return to
supplier or
use a hot
extraction
procedure
Sample acid
concentration
0.45M HN03; or 0.40M
HN03 + xM HC1
Prepare fresh
Void sample
Calibration
curve
Reproducibility is
±5%
Recalibrate and
repeat the analysis
Check instru-
ment or pre-
pare a new
calibration
curve
7-20
-------
Section No. 2.8.6
Revision No. 0
Date December 30, 1981
Page 1 of 6
6.0 CALCULATIONS AND DATA REPORTING
A matrix summarizing the quality control activities for the
calculations and the data-reporting requirements is presented in
Table 6.1.
6.1 Sample Air Volume
At standard temperature and pressure (STP) for samplers
equipped with rotameters:
(Qi + Qf)
V = —=-^—— t Equation 6-1
where
V = air volume sampled, m3,
Q. = initial air flow rate, m3/min at STP,
Qf = final air flow rate, m3/min at STP, and
t = sampling period (elapsed time), min.
For samplers equipped with flow recorders:
V = Qt Equation 6-2
where Q = average sampling rate, m3/min at STP.
Estimate the Q from the recorder chart. If the flow rate varies
less than 0.11 m3/min during the sampling period, read the flow
rate from the chart at 2-h intervals and take the average value
for Q.
Calculation for sample air volume is identical to the
hi-vol method.
6.2 Lead Concentration
6.2.1 Estimation of Lead Concentration of the Blank Filter, ug •
1. For testing of the large batches of filters (>500 fil-
ters) select at random 20 to 30 filters from a given batch. For
small batches (<500 filters) a lesser number of filters may be
taken. Cut one 1.9 cm x 20.3 cm (3/4 in. x 8 in.) strip from
7-21
-------
Section No. 2.8.6
Revision No. 0
Date December 30, 1981
Page 2 of 6
each filter, anywhere in the filter. Analyze all strips, sepa-
rately, according to the directions in Subsections 5.5 and 5.6
of Section 2.8.5.
2. Calculate total lead in each filter as
PK /ml * 100 ml .. 12
Pb/ml x strip x filter
where
Ffa = Amount of lead per 465 square cm (72 square
in. ) of blank filter, pg,
jjg Pb/ml = Lead concentration determined from Subsection
5.6 of Section 2.8.5,
100 ml/strip = Total sample volume,
12 strips/filter =
_ Useable filter area, 20 cm x 23 cm (8 in. x 9 in.) _ .
Exposed area of one strip, 1.9 cm x 20 cm (3/4 in. x 8 in.)
3. Calculate the mean, F, , and the relative standard de-
viation (100 x standard deviation/mean).
n
I Fb
F, = - - Equation 6-3
on
where
F. = average amount of lead per 72 square inches of
filter, pg
F, = amount of lead per 72 square inches for each
1 filter, |jg
n = number of blank filters analyzed.
The standard deviation (SD) of the analyses for the blank fil-
ters is given by Equation 6-4,
SD =
n
- 2
n-1
1/2
Equation 6-4
The relative standard deviation (RSD) is the ratio
7-22
-------
Section No . 2.8.6
Revision No. 0
Date December 30, 1981
Page 3 of 6
RSD =
»b
If the relative standard deviation is high enough so that in the
analyst's opinion subtraction of F^ may result in a significant
error in the pg Pb/m3 , the batch should be rejected. For ac-
ceptable batches, use the value of F, to correct all lead anal-
yses (Subsection 6.2.2) collected using that batch of filters.
If Ffa is below the lower detectable limit (LDL), no correction
is necessary.
6.2.2 Calculation of Lead Concentration of the Exposed Filter -
Lead concentration in the air sample can be calculated from data
tabulated on data record form (Figure 6.1) as follows:
(pg Pb/ml x 100 ml/strip x 12 strips/filter) - Ffa
C = ^
where
C = Concentration, pg Pb/m3,
\iq Pb/ml = Lead concentration determined from Section
2.8.5, Subsection 5.6,
100 ml/strip = Total sample volume,
12 strips/filter =
_ Useable filter area, 20 cm x 23 cm (8 in. x 9 in.) _ ,
Exposed area of one strip, 1.9 cm x 20 cm (3/4 in. x 8 in.)
F. = Average lead concentration of blank filters,
V = Air volume from Subsection 6.1.
6.2.3 Sample Calculation of Lead Concentration in Air Sample -
Data are tabulated on a data record form as shown in Figure 6.1.
The standard data are recorded and a standard curve is drawn
(Figure 6.2). The line of best fit is drawn through the points.
Average all standards analyzed throughout the run but do not
include the standards used as checks of the calibration stabil-
ity. These are check samples to be compared to the calibration
curve.
7-23
-------
Section No. 2.8.6
Revision No. 0
Date December 30, 1981
Page 4 of 6
Project
K&.
Date
u
Sample location
~
Analyst
Sample Data
Sample
number
//ft£
Air volume
at STP, m2
AJ1I
Avg
blank
"V
ug
^If
Absorbance
a. e^J-
Concentra-
tration from
cal curve,
uq Pb/ml
^.7
Total Pb,
uq Pb/m3
3.0
Standard Data
Vol. of 20 ug/ml
working standard, ml
O
f.O
/*. o
34- O
^0. 0
/ 0 O. O
Concentration,
ug Pb/ml
0.0
/. b
5. 0
6.0
/o. o
£0. O
Absorbance
O. 0 OO
O- 0 /J
0. 033
O. O^^
£ 024
0. ;$t>
Checked by
fr.
Figure 6.1. Example of a data record form.
7-24
-------
Section No. 2.8.6
Revision No. 0
Date December 30, 1981
Page 5 of 6
0.20
0.15
0)
u
c
(0
.a
w 0.10
0.05
i I r
10
ug Pb/ml
12
14
16
18
20
Figure 6.2. Calibration curve.
7-25
-------
Section No. 2.8.6
Revision No. 0
Date December 30, 1981
Page 6 of 6
To calculate total Pb of a sample use equation from Subsec-
tion 6.2.2.
f(5.7 ua/ml)(100 ml/strip)(12 strip/filter)] - (0)
C =
C = 3.0 u g Pb/m .'
(2291 nT)
TABLE 6.1. ACTIVITY MATRIX FOR CALCULATION AND DATA REPORTING
Activity
Acceptance limits
Frequency and method
of measurements
Action if
requirements
are not met
Calculations
(1) sample
volume
(2)
Fb, blank
Al1 needed data
available; relative
standard deviation of
F. is not high
Visual check for each
sample; repeat all
calculations
(3) SD and RSD
of F. values
(4) sample
concentration
Void sample;
indicate
errors and
make correc-
tions
Analysis data
form
All data and calcu-
lations are given
Visual check
Complete
missing data
values
Documentation
and sample
verification
Documentation complete
for calculation of
concentration; all
sample and data
identification numbers
match; absence of evi-
dence of malfunction
or sample loss
Visual check
each sample
for
Void sample
Documentation
of report
data
All needed data
available
Visual check for
each sample
Void sample
7-26
-------
Section No. 2.8.7
Revision No. 0
Date December 30, 1981
Page 1 of 3
7.1 Atomic Absorption Spectrophotometer
As previously indicated, major maintenance and calibration
should be done by service engineers or qualified operators. The
following general maintenance procedures should be carried out
only after consulting the manufacturer's manual.
7.1.1 Light Source - When problems are concerned with a light
source, check the hollow cathode lamp or electrodeless discharge
lamp mounting bracket, lamp connection, and make sure the in-
strument is plugged in, turned on, and warmed up. If line
voltages are low, operate the power supply from a variac which
is set to give maximum voltage. Lamp current meter fluctuation
can be reduced by using a constant voltage sine wave trans-
former .
7.1.2 No Absorbance Response - Make sure that the lamp is
lighted, properly aligned, and that the wavelength, slit, and
range controls are properly adjusted. If the meter cannot be
zeroed, (1) adjust the level of the burner head to avoid inter-
cepting the light beam, and (2) clean the lamp and window, or
photometer cover windows, with a dilute solution of a mild
7-27
-------
Section No. 2.8.7
Revision No. 0
Date December 30, 1981
Page 2 of 3
detergent and rinse several times with distilled water. Dirty
windows or lenses are a major problem when operating the instru-
ment below 2300 A° (230 nm).
7.1.3 Readout Noisy, Flame On - Check the lamp current setting,
fuel and oxidizer flow rates, the leviner to make sure it is
draining properly, the nebulizer for corrosion around the tip,
the adjustment of the nebulizer capillary, the burner head (it
may need cleaning with razor blade), the acetylene cylinder
pressure, the air pressure, and the air line filter.
7.1.4 Poor Sensitivity (Within 50% of That Suggested in the
Analytical Method Book) - Check the sensitivity obtainable for
several other elements to ascertain that the low sensitivity is
not due to the lamp used. Check the slit width, wavelength,
range setting, the burner alignment, the adjustment of the
nebulizer capillary, the fuel/oxidant flow rate ratio to ascer-
tain that it is optimized for the element to be analyzed. Make
sure that the lamp current is not above the recommended value,
check the lamp alignment, and the concentration of the standard
solution used.
All other maintenance problems such as cleaning of mirrors
or gratings should be discussed with the manufacturer or service
representative.
7-28
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 1 of 12
8.0 AUDITING PROCEDURE
An audit is an independent assessment of the quality of
data. Independence is achieved by having the audit made by an
operator other than the one conducting the routine field mea-
surements and by using audit standards and equipment different
from those routinely used. Routine quality assurance checks
conducted by the operator are necessary for obtaining and re-
porting good quality data, but they are not to be considered as
part of the auditing procedure.
Based on the results of the Reference Method Test10 for
lead analysis and Hi-Vol Sampling Method2, three performance
audits and a system audit are recommended and are described in
detail in the subsequent sections.
The basic purpose of an auditing program is to ensure the
integrity of the data and to assess the data in terms of ac-
curacy. Techniques for estimating the accuracy of the data are
given in Section 2.0.8 of Volume II of this Handbook.
8.1 Performance Audits
Performance audits are independent checks made by the
supervisor or auditor to evaluate the quality of data produced
by the total measurement system (sample location, sample ana-
lysis and data processing). Performance audits are normally a
quantitative appraisal of quality.
Three performance audits of individual variables are recom-
mended:
1. Audit of flow rate calibration
2. Audit of lead analysis
3. Audit of data processing.
8.1.1 Audit of Flow Rate Calibration - The frequency of the
audit of the flow rate depends on the use of the data (e.g., for
PSD air monitoring or for SLAMS). It is recommended that the
flow rate of each hi-vol sampler be audited each quarter.
7-29
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 2 of 12
1. Conduct the flow rate audit using a reference flow
(ReF) device, or a similar device.
2. Audit the flow rate at one flow rate. The ReF device
used for auditing must be different from the one used to cali-
brate the flow of the hi-vol sampler being audited.
3. Operate the hi-vol sampler at its normal flow rate
with the audit device in place.
4. Great care must be used in auditing the hi-vol sam-
plers having flow regulators because the introduction of resist-
ance plates in the audit device can cause abnormal flow patterns
at the point of flow sensing. For this reason, the orifice of
the flow audit device should be used with a normal glass fiber
filter in place and without resistance plates in auditing flow
regulated hi-vol samplers, or other steps should be taken to
assure that flow patterns are not disturbed at the point of flow
sensing.
5 . Use the known audit flow measurement and the flow
measured by the sampler's normal flow indicator to calculate
percent difference (Equation 8-1), a measure of inaccuracy.
Both flows must be referenced to same temperature and pressure.
Let X- represent the known flow rate, Y. the measured flow rate,
T*Vt
and d, the percent difference for the i — audit:
100. Equation 8-1
Thus if Yi = 52 ft3/min and Xi = 50 ft3/min,
then
di =
If di is greater than ±7% for any one check, recalibrate before
resuming the sampling.
USEPA uses ReF device with five orifice plates that mount onto
the faceplate of the hi-vol adaptor; this device may be pur-
chased from Dexco, Co., Inc., 630 Chapel Hill Blvd., Burling-
ton, N. C. 27215.
7-30
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 3 of 12
6. Report the Y^, the X^, and the d^ on an X-and-R chart
(Figure 8.1) under "Measurement Result, Items 1 and 2." Record
the d^ in the cells preceded by the "Range R." The d. can be
positive or negative, but the range is always positive; so
retain the sign of the difference since it may indicate trends
and/or consistent biases. The steps in the construction of a
quality control chart and the interpretation of the results are
in Appendix H, Volume I of this Handbook.11
7. Repeat the above for each flow rate calibration audit;
plot all points on the chart; and connect the points by drawing
a straight line. Tentative limits are ±4.7% (warning lines) and
±7% (out-of-control lines). Out-of-control points indicate
possible problems in calibration errors or instrument damage.
Recalibrate the sampler prior to further sampling when out of
control. After 15 to 20 points are plotted, new control and
warning limits may be derived, as described in Appendix H of
Volume I of this Handbook.11 Do not increase the control and
warning limits, however, more stringent limits may be
established.
8.1.2 Audit of Lead Analysis - Each calendar quarter, audit the
lead analysis using glass fiber filters containing a known quan-
tity of lead. Audit samples 'are prepared by depositing a lead
solution Pb (N03)2/ on 1.9 cm x 20 cm (3/4 in. by 8 in.) unex-
posed glass fiber filter strips, and allowing to dry thoroughly.
It is required that the audit samples be prepared using reagents
different from those used to generate the lead calibration curve
in Section 2.8.5. If the routine network operators are used to
perform the audit, these operators must not know the audit
values prior to the audit. This means another individual must
administer the audit program. Prepare blind audit samples in
the following concentration ranges:
7-31
-------
* AND R CHART
-a
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DATE
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s:
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58
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Figure 8.1. Quality control chart for flow rate calibration audit.
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 5 of 12
Range Cone, ug Pb/strip Cone, uq Pb/m3*
1 100 to 300 0.5 to 1.5
2 600 to 1000 3.0 to 5.0
^Calculation of lead concentration in pg/m3 is based on sampling
at 1.7 m3/min for 24 h on an 20 cm x 25 cm (8 in. x 10 in.)
glass fiber filter.
Analyze at least one audit sample in each of the two ranges
each day that samples are analyzed. If samples are analyzed
only once per quarter, analyze at least two audit samples in
each of the two ranges. The percentage difference d between the
audit concentration (pg Pb/strip) and the analyst's measured
concentration (pg Pb/strip) is used to calculate analysis inac-
curacy, (Equation 8-2),
d = " x 1QO Equation 8-2
Pb(A)
where
d = Percentage difference,
= Concentration measured by the lab analyst,
pg Pb/ml, and
= Audited or known concentration of audit sample,
|jg Pb/ml.
Tabulate the percentage differences on an X and R chart
(optional). The upper and lower control lines and the upper and
lower warning lines should also be plotted (Figure 8.2) and used
as guidelines to determine when results are questionable and
corrective action needs to be taken. Record on the chart the
nature of the corrective action. Details for construction of a
quality control chart are given in Appendix H of Volume I of
this Handbook.11
The recommended control limits for the two audit sample
ranges (0.5 to 1.5 and 3 to 5 pg Pb/m3) are the 90th percentile
values for d based on the results of seven audits (8/77, 1/78,
6/78, i/79, 7/79, 1/80, and 7/80) performed by the Environmental
7-33
-------
If
£p
tot
a
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'c
d
-j ^
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i
^
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t-
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Figure 8.2. Quality control chart for A.A. analytical audit.
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 7 of 12
Monitoring Systems Laboratory, USEPA, Research Triangle Park,
North Carolina.12'13'14'15 By definition, 90% of the laboratory
participants in the audit obtained values of d less than the
values tabulated below. The control limits are expected to be
exceeded by 10% of the laboratories to be audited, based on
these seven audits over four years. The 90th percentile values
and the known audit concentrations are given below for each
audit concentration range.
Audit date
8/77
1/78
6/78
6/78
1/79
7/79
1/80
7/80
0.5 to 1.5 ug Pb/m3
Known audit
concentration, 90th
pg Pb/m3
1.8
0.6
0.4
1.5
1.5
1.2
0.9
0.6
3 to 5 yg Pb/m3
Known audit
concentration, 90th
yg Pb/m3
4.0
5.0
3.5
3.5
4.5
4.2
percentile for d,
%
45
35
31
15.3
15.1
16
16.1
11.7
percentile for d,
%
23.5
12.5
14.8
13.9
20.0
9.8
Audit date
8/77
6/78
1/79
7/79
1/80
7/80
Based on the results of these seven audits, the recommended 90th
percentile control limits for audit samples are ±16% for both
the 0.5 to 1.5 yg Pb/m3 and the 3.0 to 5.0 |jg Pb/m3 concentra-
tion ranges. The control limits of ±16% are also recommended
7-35
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 8 of 12
for the lower Pb concentrations range (0.5 to 1.5 yg Pb/m3) on
the assumption that the first three audits are not representa-
tive of current limits (last four audits).
The method user should take part in the EPA semi-annual
audit program for lead analysis. For more information on the
EPA lead audit program, see Section 2.0.10 of this Handbook.
8.1.3 Audit of Data Processing - A data processing audit allows
for correction of errors after the original calculations have
been performed. The audit rate of seven measurements out of
every 100 is recommended. The audit is made starting with the
raw data on the data form. When the original and the audit
calculations do not agree, all calculations for the correspond-
ing audit period should be recalculated. The nature of the
error(s) should be clearly explained to the appropriate per-
sonnel in order to minimize their reoccurrence. Audit values
are recorded in the data log and reported to the supervisor for
review. These results can be used to check computer programs
and manual methods of data processing.
8.2 System Audit
A system audit is an on-site inspection and review of the
quality assurance system used for the total measurement system
(sample collection, sample analysis, data processing, etc.).
Whereas performance audits are a quantitative assessment, system
audits are normally a qualitative appraisal.
A system audit should be conducted for a monitoring system.
The auditor should have sufficient experience with the method
and an extensive background with the characterization technique
that he is auditing. Figure 8.3 can be used as a preliminary
form for use in a system audit. These questions should be
checked for the applicability to the particular local, State, or
Federal agency. One should also refer to Section 2.0.11 of this
volume of the Handbook for further details on a system audit.
7-36
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 9 of 12
1. What types of hi-vol samplers are utilized in the network?
/Tlntor f/JnrKc model rl
2. How often are the samplers run? na)daily, (b) once every six days,
(c) once every 12 days, (d)
3. What type and quality of filter and number of filters is being utilized?
_ qlQss -pW . Spec_'JYh&-LL
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 10 of 12
15. Calibration curve check? QK
16. Calculation procedure check?
17. Are reagents, calibration standards, samples, etc., labeled clearly with
test numbers, dates, and all pertinent data? /*?.* _
Comments:
Figure 8.3. Checklist for use by auditor.
7-38
-------
Section No. 2.8.8
Revision No. 0
Date December 30, 1981
Page 11 of 12
The system audit should be performed at the beginning of
the monitoring program and annually thereafter unless problems
occur to require more frequent system audits.
8.3 Activity Matrix
Table 8.1 summarizes the quality assurance activities for
auditing procedures.
7-39
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Section No. 2.8.8
Revision No. 0
Date December 30,
Page 12 of 12
1981
TABLE 8.1. ACTIVITY MATRIX FOR AUDITING PROCEDURE
Audit
Acceptance limits
Frequency and method
of measurement
Action if
requirements
are not met
Flow rate
audi t
d, =
100
Yi
Xi
Yi -
Xi
routinely measured
flow rate, and
= audited flow rate
Audit each sampler
quarterly; same
method as for cali-
bration procedure
Corrective
action before
resuming sam-
pling; action
noted on X-
and- R chart
Audit of analy-
sis process
using audit
samples
d should be within ±16%
for both the 0.5 to 1.5
ug Pb/m3 and the 3 to
5 ug Pb/m3 concentration
ranges (Subsec 8.1.2)
Analyze an audit
sample in each of
the two concen-
ranges at
least once each ana-
lysis day and at
least twice per
calendar quarter
that samples are
analyzed (Subsec
8.1.2)
Calibration
curve
checked, if
necessary; a
new reference
sample
checked, and
if accepta-
ble, analysis
resumed; data
accuracy cal-
culated per
Sec 2.0.8
Data
processing
audit
The reported value
should agree with the
audited value within
round-off error
1 in 14 samples or
1/mo, whichever is
greater; independent
calculations from
raw data to final
recorded data
Calculations
for al1 sam-
ples col-
lected since
previous
audit checked
and corrected
System
audit
Method described in
this section of
Handbook
At the beginning of
a new monitoring
system, and period-
ically as appro-
priate; observation
of procedures and
use of a checklist
Improved
methods and/
or training
programs
initiated
7-40
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Section No. 2.8.12
Revision No. 0
Date December 30, 1981
Page 1 of 2
12.0 REFERENCES
1. Reference Method for the Determination of Lead in
Suspended Particulate Matter Collected from Ambient
Air, published in Federal Register, Vol. 43, No. 194,
Thursday, October 5, 1978.
2. Code of Federal Regulations 40, part 50.11, Appendix B
(Hi-Vol Method), July 1, 1975 pp. 12-16.
3. Scott, D. R. et al. Atomic Absorption and Optical
Emission Analysis of NASN Atmospheric Particulate
Sampler for Lead. Environ. Sci. and Tech. 10, 877-
880, 1976.
4. Skogerbee, R. K. et al. Monitoring for Lead in the
Environment. pp. 57-66, Dept. of Chemistry, Colorado
State Univ., Fort Collins, Colorado 8-523, Submitted
to National Science Foundation for publication, 1976.
5. Zdrojewaki, A. et al. The Accurate Measurement of
Lead in Airborne Particulates. Inter. J. Environ.
Anal. Chem., 2, 63-77, 1972.
6. Slavin, W. Atomic Absorption Spectroscopy. Published
by Interscience Company, New York, NY, 1968.
7. Kirkbright, G. F. and Sargent. M. Atomic Absorption
and Fluorescence Spectroscopy. Published by Academic
Press, New York, NY, 1974.
8. Dubois, L. et al. The Metal Content of Urban Air.
JAPCA, 1£, 77-78, 1966.
9. U.S. Environmental Protection Agency Report No. 600/
4-77-034, June 1977. Los Angeles Catalyst Study
Symposium, pp. 223.
10. Long, S. et al. Lead Analysis of Ambient Air Particu-
lates: Interlaboratory Evaluation of EPA Lead Refer-
ence Method JAPCA, 29, 28-31, January 1979.
11. Quality Assurance Handbook for Air Pollution Measure-
ment Systems, Volume I, Principles. EPA-600/9-76-005.
7-41
-------
Section No. 2.8.12
Revision No. 0
Date December 30, 1981
Page 2 of 2
12. Bromberg, S. M., R. L. Lampe, and B. I. Bennett. Sum-
mary of Audit Performance: Measurement of S02, N02 ,
CO, Sulfate, Nitrate, Lead and Hi-Vol Flow Rate -
1978, EPA-600/4-80-017. U.S. Environmental Protection
Agency, Research Triangle Park, N.C., June 1980.
13. Bromberg, S. M., R. L. Lampe, and B. I. Bennett. Sum-
mary of Audit Performance: Measurement of S02, NO2,
CO, Sulfate, Nitrate, Lead, Hi-Vol Flow Rate -1977,
EPA-600/4-79-014. U.S. Environmental Protection
Agency, Research Triangle Park, N.C., February 1979.
14. U.S. Environmental Protection Agency. National Per-
formance Audit Program. 1979 Proficiency Surveys for
Sulfur Dioxide, Nitrogen Dioxide, Carbon Monoxide,
Sulfate, Nitrate, Lead and High Volume Flow. EPA-600/
4-81-025, April 1981.
15. Bennett, B. I., R. L. Lampe, L. F. Porter, A. P.
Hines, and J. C. Puzak. National Performance Audit
Program. 1980 Proficiency Surveys for Sulfur Dioxide,
Nitrogen Dioxide, Carbon Monoxide, Sulfate, Nitrate,
Lead and High Volume Flow. U.S. Environmental Protec-
tion Agency, Research Triangle Park, N. C., September
1981.
16. Catalog of NBS Standard Reference Materials. NBS
Special Publication 260, 1982 - 83 Edition. U.S. De-
partment of Commerce, NBS, Washington, D. C. November
1981.
7-42
-------
Review Exercise
Now that you've completed the assignment for Section 7, please answer the follow-
ing questions. These will help you determine whether you are mastering the
material.
1. The lead reference method requires that paniculate lead be collected by a(n)
(?) and analyzed by a(n) (?)
a. impinger, ultraviolet photometer
b. dust fall bucket, atomic absorption spectrophotometer
c. high volume sampler, atomic absorption spectrophotometer
d. high volume sampler, flame ionization detector
2. Before using an atomic absorption spectrophotometer for lead analysis, its
(?) should be checked.
a. sensitivity
b. reproducibility
c. both a and b, above
3. An atomic absorption spectrophotometer that is used to analyze lead samples
should have a reproducibility change of (?) percent or less.
a. 1
b. 2
c. 5
d. 10
4. True or False? In the lead reference method, lead atoms absorb light over a
broad band of wavelengths.
5. Which of the following is a(are) possible type(s) of interference(s) in the atomic
absorption analysis of lead?
a. chemical
b. light scattering
c. both a and b, above
6. Acetylene cylinders used in the atomic absorption analysis of lead should be
replaced when their pressures drop below (?) psig.
a. 25 to 50
b. 50 to 100
c. 100 to 150
d. 150 to 200
7-43
-------
7. Air used in the atomic absorption analysis of lead should be as free of
(?) as possible.
a. paniculate matter
b. oil
c. water
d. a and b, above
e. a, b, and c, above
8. Volumetric glassware used in the analysis of lead must be Class L?J
a. A
b. B
c. C
9. Which of the following should be used in cleaning glassware for lead analysis?
a. laboratory detergent
b. 20% (w/w) HNO3
c. distilled deionized water
d. both a and c, above
e. a, b, and c, above
10. If possible, reagents used in lead analysis should be at least (?)
a. ACS reagent grade
b. practical grade
c. technical grade
11. Which of the following is a(are) desirable characteristic(s) of glass-fiber filters
used to collect paniculate lead?
a. minimal variation of lead content from filter to filter
b. high lead content
c. both a and b, above
12. True or False? The same source or batch of distilled deionized water must be
used for all purposes in lead analysis.
13. Stock lead solutions may be stored up to (?) year(s).
a. 1
b. 2
c. 3
d. 5
14. True or False? One strip of a paniculate lead filter collected near a roadway
should be analyzed to determine the ambient air lead concentration.
15. Which of the following is an(are) EPA-accepted method(s) of removing lead
from paniculate-matter filters?
a. hot extraction procedure
b. ultrasonic extraction procedure
c. liquid chromatography extraction procedure
d. both a and b, above
e. both b and c, above
7-44
-------
16. Which of the following should be performed during lead extraction?
a. keep the lead sample covered during extraction
b. allow sample filter to soak in distilled deionized water for 30 minutes
c. filter the extracted sample to remove paniculate matter
d. a and b, above
e. a, b, and c, above
17. True or False? In the hot extraction procedure, the lead sample should be
evaporated to dryness.
18. True or False? Settled solids in a lead sample should not be disturbed when the
sample is aspirated into the flame of an atomic absorption spectrophotometer.
19. True or False? Lead samples having concentrations that exceed the calibrated
range of an atomic absorption spectrophotometer should be diluted with
distilled deionized water.
20. Lead standard working solutions should be prepared (?)
a. daily
b. weekly
c. biweekly
d. monthly
21. At least (?) standard(s) plus a reagent blank should be used to
prepare a lead calibration curve for an atomic absorption spectrophotometer.
a. 1
b. 2
c. 3
d. 5
22. True or False? Control standards should be periodically analyzed, using an
atomic absorption spectrophotometer, during the analyses of lead samples.
23. If a control standard analysis deviates more than (?) percent from
the value predicted by the calibration curve of an atomic absorption spec-
trophotometer, corrective action should be taken.
a. 0.5
b. 1
c. 5
d. 10
24. Under the conditions described below, the lead concentration obtained using
the lead reference method is (?) /ig/std ms.
a. 0.826
b. 0.044
c. 1.00
d. 1.04
Given: Total volume of sample solution: 100 mL/strip
Lead concentration of sample solution: 2.0 /tg/mL
Average lead concentration of blank filters: 100 /xg
Volume of air sampled: 2300 std m3
7-45
-------
25. True or False? Current fluctuations of lead atomic absorption lamps can be
reduced by using constant voltage sine wave transformers.
26. Which of the following is a(are) possible cause(s) for being unable to "zero" an
atomic absorption spectrophotometer?
a. burner head intercepting the light beam
b. dirty spectrophotometer windows
c. lamp current too high
d. a and b, above
e. a, b, and c, above
27. Which of the following is a(are) possible cause(s) for the readout of an atomic
absorption spectrophotometer being noisy with its flame on?
a. burner head corroded
b. nebulizer misadjusted
c. lamp current misadjusted
d. a and b, above
e. a, b, and c, above
28. True or False? A misaligned lamp may cause an atomic absorption spec-
trophotometer to lose sensitivity.
29. Performance audits should be conducted for which of the following activities of
the lead reference method?
a. flow rate calibrations of high volume samplers
b. lead analysis
c. data processing
d. a and b, above
e. a, b, and c, above
30. During a performance audit of a high volume sampler, the sampler should be
operated at (?)
a. 40 cfm
b. 50 cfm
c. 60 cfm
d. its normal sampling flow rate
31. A high volume sampler should be recalibrated if a performance audit results in
a relative difference between the sampler's measured flow rate and the audit
flow rate of greater than ± (?) percent.
a. 3
b. 7
c. 15
d. 20
7-46
-------
32. Which of the following is(are) required in the performance auditing of lead
analysis?
a. Audit samples must consist of lead solutions deposited on glass-fiber filter
strips.
b. Audit samples must be prepared using reagents different from those used to
generate lead calibration curves.
c. Routine analysts must know the audit values before the audit.
d. a and b, above
e. a, b, and c, above
33. True or False? In auditing lead data processing, when the original calculations
do not agree with the audit calculations, all original calculations for the period
under audit should be recalculated.
34. Control charts should be maintained for (?) audit results.
a. high volume sampler flow-rate calibration
b. lead analysis
c. both a and b, above
35. Which of the following should be determined during a systems audit of a lead-
monitoring network?
a. types of high volume samplers and paniculate matter filters used
b. high volume sampler and atomic absorption spectrophotometer calibration
procedures
c. whether there is sufficient sampling and analysis documentation
d. b and c, above
e. a, b, and c, above
7-47
-------
Section 7
Review Exercise Answers
Page(s) of Section 7
of this Guidebook
1. c 4
2. c 5
3. c 5
4. False 7
5. c 7
6. b 8
7. e 8
8. a 9
9. e 9
10. a 12, 13
11. a 12
12. True 12
13. b 13
14. False 14
15. d 14, 15
16. d 14, 15
17. False 14
18. True 16
19. False 17
20. a 17
21. c 18
22. True 18
23. c 18
24. c 23
25. True 27
26. d 27
27. e 28
28. True 28
29. e 29
30. d 30
31. b 30
32. d 31
33. True 36
34. c 31, 32, 33, 34
35. e 37, 38
7-48
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Section 8
Automated Analyzers for
Nonmethane Organic Compounds
Reading Assignment
Pages 1 through 31 of EPA 600/4-81-015 Technical Assistance Document for the
Calibration and Operation of Automated Non-Methane Organic Compound
Analyzers.
Reading Assignment Topics
Reference measurement principle for nonmethane hydrocarbons
Problems associated with analyzers for nonmethane organic compounds
(NMOC)
Installation and operation of NMOC analyzers
Maintenance and troubleshooting of NMOC analyzers
Calibration of NMOC analyzers
Quality control for NMOC analyzers
Learning Goal and Objectives
Learning Goal
The purpose of this section is to familiarize you with automated nonmethane
organic compounds (NMOC) analyzers that use the reference measurement princi-
ple for nonmethane hydrocarbons.
Learning Objectives
At the end of this section, you should be able to —
1. describe the nonmethane hydrocarbons reference measurement principle,
2. define and recognize the rationale for the term "nonmethane organic
compounds,"
3. express NMOC concentrations in appropriate reporting units,
4. recognize and describe solutions for at least eight potential problems
associated with NMOC analyzers, sample handling systems, or analyzer
shelters,
5. describe at least eight activities involved in the installation of NMOC
analyzers,
8-1
-------
6. recognize at least six items that should be included in an analyzer logbook,
and
7. describe maintenance, troubleshooting, calibration, and quality control pro-
cedures for NMOC analyzers.
Reading Guidance
• Although analyzers using the reference measurement principle for nonmethane
hydrocarbons, which is described in the second paragraph of page 3 of the
reading assignment, are available, none of them have been designated as
reference methods by the U.S. EPA.
• The traceability requirement described on page 25 of the reading assignment
should be applied where possible to all gaseous standards.
• Refer often to the tables and figures of the assigned reading material as you
progress through the assignment.
• When you have finished the reading assignment, complete the review exercise
for Section 8. It begins on the following page.
• After you have answered the review exercise questions, check your answers.
The correct answers are listed on the page immediately following the review
exercise.
• For any review exercise questions that you answered incorrectly, review the
page(s) of the reading assignment indicated on the answers page.
• After you have reviewed your incorrect answers (if any), take the Final
Examination for this course. Follow the directions listed in the Course
Introduction section of this guidebook.
• Your course grade results will be mailed to you.
8-2
-------
Review Exercise
Now that you've completed the assignment for Section 8, please answer the follow-
ing questions. These will help you determine whether you are mastering the
material.
1. The reference measurement principle for nonmethane hydrocarbons consists of
separating methane from other organic compounds by (?)
and measuring methane and other organic compounds by (?)
a. thin layer chromatography, flame ionization detection
b. liquid chromatography, ultraviolet photometry
c. gas chromatography, flame ionization detection
d. ion chromatography, infrared spectroscopy
2. Which of the following parameters are measured directly by analyzers using
the nonmethane hydrocarbon reference measurement principle?
a. methane
b. total hydrocarbons
c. nonmethane hydrocarbons
d. a and b, above
e. a, b, and c, above
3. True or False? A flame ionization detector responds uniformly from one
hydrocarbon species to another.
4. Which of the following enhance(s) the uniformity of response of a flame ioniza-
tion detector to different hydrocarbons?
a. injection of hydrocarbons into detector via an air carrier
b. injection of hydrocarbons into detector via an inert carrier gas
c. both a and b, above
5. The concentration resulting from the subtraction of methane concentration
from total hydrocarbon concentration, determined by flame ionization detec-
tion, should be referred to as nonmethane organic compounds (NMOC) con-
centration because (?)
a. it includes oxygenated organics that contribute to the increase of
photochemical oxidant concentrations
b. flame ionization detectors exhibit some sensitivity to oxygenated compounds
c. both a and b, above
8-3
-------
6. Hydrocarbon concentrations should be reported as ppmC in order to
a. eliminate the confusion of using several different concentration units
b. normalize the responses of flame ionization detectors to different organic
compounds
c. both a and b, above
7. Six ppm of propane (C3Hg) is equal to (?) ppmC.
a. 6
b. 2
c. 9
d. 18
For each of questions 8 through 10, match the NMOC analyzer problem with its
appropriate remedy.
c.
all analyzer channels (total organic
compounds, methane, NMOC)
should be properly calibrated
NMOC response should be cali-
brated to a propane standard
calibration gases should be
diluted to ensure that they contain
20.9 ±0.3% oxygen
8. large differences in the
per-carbon response to
different NMOC species
9. variations in oxygen concentration
affect sensitivity of flame
ionization detector
10. NMOC concentrations are
subject to large, relative errors
because they are the differences
of relatively large and nearly
equal numbers
11. Temperature inside the monitoring shelter of an NMOC analyzer should be
maintained within a range nf (?) °C.
a. 10 to 40
b. 20 to 30
c. 20 to 40
d. 30 to 50
12. Which of the following can prevent moisture in sample air from damaging
NMOC analyzers?
a. sample line moisture traps
b. maintaining temperature of monitoring shelter within 5 to 7°C of outside
temperature
c. both a and b, above
13. Voltage supplied to an NMOC analyzer should be monitored (?)
a. when the analyzer is installed
b. at the beginning of heating and cooling seasons
c. both a and b, above
8-4
-------
14. Which of the following should be complied with when installing a sample-air
manifold for an NMOC analyzer?
a. air conditioning vents should be positioned away from the manifold
b. the manifold's sample ports should be pointed toward the floor of the
shelter
c. both a and b, above
15. The sample manifold of an NMOC analyzer should be regularly inspected for
a. paniculate matter
b. moisture
c. leaks
d. a and c, above
e. a, b, and c, above
16. True or False? An NMOC analyzer should be set up and operated immediately
after it is unpacked.
17. True or False? Only clean or new Teflon® tubing should be used to supply
hydrogen to an NMOC analyzer.
18. Hydrogen used by NMOC analyzers should contain less than (?)
ppmC total organic compounds (TOC).
a. 0.1
b. 1
c. 5
d. 10
19. True or False? Signal cable used to connect an NMOC analyzer to its concen-
tration readout device should not be spliced and should be as long as possible.
20. Sample-gas tubing for an NMOC analyzer should be composed of
a. polypropylene
b. polyvinyl chloride
c. Teflon®
d. both b and c, above
21. True or False? An all-Teflon® paniculate matter filter should be installed in
the sampling line of an NMOC analyzer.
22. Which of the following should be accomplished before operating an NMOC
analyzer?
a. understand the basics of analyzer operation
b. determine that there are no leaks in the analyzer's hydrogen-flow system
c. prepare a set of analyzer operating summary sheets
d. a and b, above
e. a, b, and c, above
8-5
-------
23. An NMOC analyzer logbook should contain which of the following?
a. analyzer's instruction manual
b. analyzer identification
c. calibration, routine checks, and maintenance data
d. b and c, above
e. a, b, and c, above
24. Multipoint calibrations of NMOC analyzers should be (?)
a. performed once per week
b. performed once per month
c. performed once per year
d. based on analyzer performance
25. Which of the following operational parameters of an NMOC analyzer should
be routinely checked?
a. pressure gauge readings
b. rotameter readings
c. pyrometer readings
d. a and b, above
e. a, b, and c, above
26. Which of the following maintenance activities for an NMOC analyzer should
be performed at least once every 180 days?
a. leak check of hydrogen flow systems
b. head pressure check of sample pump
c. soiling check of sample line paniculate matter filter
d. a and b, above
e. a, b, and c, above
27. Which of the following operating parameters of an NMOC analyzer can be
evaluated from a chromatogram?
a. sensitivity
b. gate timing
c. both a and b, above
28. Which of the following indicate(s) possible leaks or obstructions in the flow
systems of an NMOC analyzer?
a. decreased pressure gauge readings of flow systems
b. calibration curve drift in one direction
c. inability to perform balance procedures
d. a and b, above
e. a, b, and c, above
29. True or False? A leak in a gas-flow system of an NMOC analyzer should be
identified with leak detector solution only after the general area of the flow
system containing the leak has been determined by pressurizing the flow
system.
8-6
-------
For each of questions 30 through 32, match the NMOG analyzer response with its
appropriate calibration standard when obtaining NMOC data for predicting ozone
concentrations.
30. Methane (CH*) a. methane
31. Total Organic Compounds (TOG) b. ethane
32. NMOC c. propane
33. Zero air used in the calibration of NMOC analyzers should contain which of
the following?
a. 20.9 ±0.3% oxygen
b. nitrogen
c. carbon monoxide
d. a and b, above
e. a, b, and c, above
34. Zero air used in the calibration of NMOC analyzers should contain less than
(?) ppmC.
a. 0.1
b. 1
c. 2
d. 5
35. True or False? Air used in the preparation of zero air for the calibration of an
NMOC analyzer should be obtained from air inside the analyzer's monitoring
shelter.
36. True or False? A heatless air dryer should be used to remove moisture from
zero air used in the calibration of NMOC analyzers.
37. Calibration gases must be delivered to the inlet of an NMOC analyzer
(?) atmospheric pressure.
a. at
b. below
c. above
38. Calibration gases used to calibrate an NMOC analyzer should be traceable to
(?)
a. standard reference material of the National Bureau of Standards
b. certified reference material
c. either a or b, above
39. Methane and propane standards used to calibrate NMOC analyzers should be
analyzed (?) to ensure that concentrations of organic contaminants
remain less than 0.1 ppmC.
a. weekly
b. monthly
c. quarterly
d. yearly
8-7
-------
40. Which of the following must be complied with when calibrating an NMOC
analyzer?
a. calibration manifold vented to the atmosphere
b. calibration gases introduced through analyzer's calibration port
c. gas flow to calibration manifold 20 to 50% greater than analyzer's sample
flow demand
d. a and c, above
e. a, b, and c, above
41. For dynamic dilution calibrations of NMOC analyzers, diluent-to-pollutant
flow rate ratios should be greater than (?) : 1.
a. 2
b. 10
c. 50
d. 100
42. True or False? Preparing a calibration gas by dynamic dilution requires
accurate flow rate measurements. ,
43. When using a soap bubble flowmeter, select a bubble tower that will permit a
flow measurement for at least (?) seconds.
a. 5
b. 10
c. 15
d. 30
44. Wet-test meters should generally be used to measure flows within a range of
(?) meter revolution(s) per minute.
a. V£ to 1
b. V$ to 2
c. VS to 3
d. 1 to 3
45. True or False? Flows through wet-test meters should be measured by complete
meter revolutions only.
46. Under the conditions described below, the NMOC concentration of an air sam-
ple obtained from an NMOC analyzer is (?) ppmC.
a. 0.100
b. 0.300
c. 0.900
d. 1.17
Given: Methane calibration curves:
CH4 response: 9.000X + 0.200
TOG response: 9.900X + 0.100
Propane calibration curve:
TOG response: 3.300
NMOC analyzer responses to air sample:
CH4 response: 6.5% of analyzer's concentration range
TOG response: 10.0% of analyzer's concentration range
8-8
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47. Under the conditions described below, the span drift of the NMOC analyzer is
(?) percent.
a. 0.0
b. 9.9
c. 10.0
d. 10.1
Given: Analyzer's response to Level 1 span: 88% of analyzer's full scale
Analyzer's response to Level 1 zero: 0% of analyzer's full scale
Level 1 span concentration: 80% of analyzer's full scale
Slope of analyzer's multipoint calibration curve: 1.100
48. True or False? Level 2 zero and span gas must be introduced through the nor-
mal sample inlet of an NMOC analyzer.
8-9
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Section 8
Review Exercise Answers
Page(s) of TAD for NMOC
Analyzers
1. c 3
2. d 3
3. False 2
4. b 2
5. c 1
6. c 2
7. d 2
8. b 4
9. c 4
10. a 4
11. b 6
12. c 6
13. c 7
14. a 7
15. e. 7
16. False 8
17. False 15
18. a 15
19. False 16
20. c 16
21. True 16
22. e 16
23. e 9
24. d 17
25. e 17
26. d 18
27. c 18
28. e 18
29. True 20
30. a 23
31. a 23
32. c 23
33. d 23
34. a 23
35. False 23
36. False 23
37. a 24
38. c 25
8-10
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Page
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA 450/2-82-021
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
APTI Correspondence Course 438
Reference and Automated Equivalent Measurement Methods
5. REPORT DATE
August 1983
6. PERFORMING ORGANIZATION CODE
fc
Ai
ilent Air Monitoring;
7. AUTHOR(S)
B. M. Ray
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Northrop Services, Inc.
P.O. Box 12313
Research Triangle Park, NC
10. PROGRAM ELEMENT NO.
B18A2C
27711
11. CONTRACT/GRANT NO.
68-02-3573
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Manpower and Technical Information Branch
Air Pollution Training Institute
13. TYPE OF REPORT AND PERIOD COVERED
Student Guidebook
14. SPONSORING AGENCY CODE
EPA-OANR-OAOPS
Park
7771 1
15. SUPPLEMENTARY NOTES
Project officer for this publication is R. E. Townsend, EPA-ERC, RTF, NC 27711
16. ABSTRACT
This guidebook was developed for use in the Air Pollution Training Institute's
Correspondence Course 438, "Reference and Equivalent Measurement Methods for
Ambient Air Monitoring." It contains reading assignments and review exercises
covering the following topics:
- Reference Method for Sulfur Dioxide
- Automated Equivalent Measurement Methods for Sulfur Dioxide
- Reference Methods for Ozone
- Reference Method for Total Suspended Particulate Matter
- Reference Methods for Carbon Monoxide
- Reference Methods for Nitrogen Dioxide
- Reference Method for Lead
- Automated Analyzers for Monmethane Organic Compounds
This guidebook is designed for use in conjunction with "APTI Course 464
Analytical Methods for Air Quality Standards: Student Manual" (EPA 450/2-81-018b)
and "Technical Assistance Document for the Calibration and Operation of Automated
Non-Methane Organic Compound Analyzers" (EPA 600/4-81-015).
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Training
Air Pollution
Measurement
Ambient Air Monitoring
Training Course
13B
51
68A
B. DISTRIBUTION STATEMENT Unlimited
Available from the National Technical
Information Service, 5258 Port Royal Rd.,
Springfield, VA 22161
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
163
20. SECURITY CLASS (This page).
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
8-12
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