Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
STANDARD OPERATING PROCEDURE
FOR
MEASUREMENT OF HEXAVALENT CHROMIUM
USING THE
BGI PQ167R LOW VOLUME SAMPLER
U.S. Environmental Protection Agency
Region 4, Science and Ecosystem Support Division
Athens, Georgia, 30605
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
Acknowledgement
This Standard Operating Procedure (SOP) was developed by EPA Region 4,
Science and Ecosystem Support Division. This SOP is based on the
Commonwealth of Kentucky's ambient monitoring SOP template. Special thanks
to BGI Inc. and ERG for operational content and illustrations.
For questions or comments please contact:
Greg Noah, EPA, Region 4, SESD at noah.greg@epa.gov or 706-355-8635
Mike Jones, EPA-OAQPS-AQAD at iones.mike(S)epa.gov or 919-541-0528
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
Table of Contents
I. Introduction 4
II. Installation 7
A. Sampler Siting 7
B. Sampler Installation 7
Cr+6 Retrofit Instructions 7
III. Operating Procedure 9
A. Equipment and Supplies 9
B. Sampler and Sample Media Receipt Activities 9
C. Verification 10
D. Calibration 11
E. Conducting the Sampling Event 12
Site Arrival Daily Activities 12
Preparing Sampler for a Sampling Event 13
Installing the ERG Cr+6 Filter Holder Module 16
Sample Recovery and Data Collection 16
Sample Shipping 17
IV. Quality Assurance 18
A. Flow Calibration 18
B. Flow Verifications 18
C. Independent Audits 18
V. Data Forms 18
ERG Ambient Hexavalent Chromium Data Sheet 19
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
INTRODUCTION
This procedure is designed to provide instruction on collecting hexavalent
chromium (Cr+6) in air using the BGI PQ167R air sampler for metals analysis.
The BGI PQ100 is an "Intelligent Air Pump" that can monitor its own airflow
rate and thereby adjust the pump speed to compensate for changes in load
pressure and/or other forces which would otherwise hamper the flow of air
through a filter (or sample collector). The PQ100 unit can be programmed to
begin its sampling job at a specific date, time, and stop sampling after the user
defined run time is depleted. However, the sampling time should always be
24 hours for Cr+6 sampling the Toxics in Schools Study.
The PQ100 was designed to operate from 1 standard liter per minute (1000 cc
per minute) to 25.0 standard liters per minute and is unaffected by changes in
ambient temperature and barometric pressure. The flow rate precision is
guaranteed to 2% of the calibration set point.
This SOP is designed to be a step by step method for operating the sampler
to be used in conjunction with the manufacturer's operators manual.
Laboratory Analysis Methodology may be referenced by contacting the
Eastern Research Group (ERG) directly at 919-468-7800 or by email
Julie.Swift@erg.com. Maintenance and troubleshooting should be conducted
using the BGI167R operator's manual.
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
FIGURE 1. Schematic of PQ167 Sampling System
(Cr+6 filter holder apparatus replaces PM10 inlet head)
SIZE SELECTIVE
INLET OR FILTER
MASS FLOW
SENSOR
PULSATION DAMPING
VOLUME
PUMP
MICRO PROCESSOR
VISUAL DATA DISPLAY
BATTERY
BATTERY CHARGER
A.C. POWER SUPPLY
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
FIGURE 2. PQ167R with Mounting Stand
(Cr+6 filter holder apparatus replaces PM10 inlet head and filter cassette module
and downtube assembly brace are not used)
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
INSTALLATION
A. Sampler Siting
Check the areas for safety. Ensure there will be enough room for the
operator to move freely while working, and ensure physical conditions of
the location will allow the operator to work safely.
The sampler should be set in a location unobstructed from any side. No
tree limbs or other hanging obstructions should be above the sampler. It
is suggested that the horizontal distance from the sampler to the closest
vertical obstruction higher than the sampler be at least twice the height of
the vertical obstruction. There should be no sources located nearby that
may bias sampling measurements.
Locate the sampler on a reasonably level structure at a height between
two (2) and fifteen (15) meters above the ground.
B. Sampler Installation
Assemble the sampler according to Figure 3 below omitting the
installation of the PM10 inlet head, filter cassette holder assembly, and
downtube assembly brace. For detail and illustration, refer to the BGI
PQ167 Quick Start document, pages 2 through 8.
Cr+6 Retrofit Instructions
1. The sampling unit, at this point, should have legs mounted on the
stand, and the pump and power components should be secured in
the stand according to the PQ167 Quick Start document. The
downtube, PM10 inlet head, and filter cassette holder assembly
should NOT be installed.
2. Install the downtube on the top of the cylindrical mount on the
stand. The mount should have tubing leading from the port on its
side to the inlet on the pump module.
3. The total ERG Cr+6 filter holder apparatus consists of a BGI flow
adapter with shut-off valve, stainless steel connector fitting, a
length of "U" shaped stainless steel % inch tubing, ERG filter
assembly, and a glass funnel. The ERG filter assembly and
glass funnel will be provided for each sampling run and
should not be installed until a sampling run is setup.
Place this apparatus (without ERG filter assembly) on the top
of the downtube, and ensure that the shut-off valve is in the
open position.
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
The open end of the stainless steel tubing should be capped when
sampling is not in progress to prevent contamination.
Figure 3. Sampler Assembly Diagram
(Cr+6 filter holder apparatus replaces PM10 inlet head and filter cassette module and downtube
assembly brace are not used)
01 PM10 Inlet head
03 Water collection bottle
11A Tripod frame
12 Rubber hose
34 Hose adapter
160 Sampler leg
161 Filter cassette holder assembly
162 Downtube
163 Downtube assembly brace
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
Place and level the sampler on site. To secure the sampler and protect
membrane roofs, 2x4 wooden studs may be cut into one foot sections
and fastened to the feet of the legs using lag bolts. Place sand bags on
these skids to prevent tipping of the sampler.
Connect the sampler to a grounded electrical outlet with 115 volts, and at
least 5 amp service. Protect the connector from precipitation by fastening
beneath the sampler or wrapping it with plastic tape.
If operating using a deep cycle marine battery for power, install the
external power cord by screwing the round harness into the "utility
adapter" port on top of the sampler. Attach the positive and negative
contacts to the deep cycle marine battery and secure. A fully charged
battery should provide power for at least 2 sampling runs. Depending on
the battery available, more consecutive runs may be possible. Store the
battery in a plastic container near the sampler to conceal and protect it
from the weather.
If collocated samplers will be located at the site, the two samplers must
be within four (4) meters of each other, but outside of two (2) meters.
The inlet heights must be within one (1) meter vertically.
OPERATING PROCEDURE
A. Equipment and Supplies
BGI PQ167R
ERG Cr+6 filter holder apparatus
Flow calibrator
Logbook
ERG filter assembly with glass funnel
Cooler with ice substitute
Powderfree gloves
ERG sample paperwork
B. Sampler and Sample Media Receipt Activities
1. Plug sampler into AC power and charge the internal battery for at
least 24 hours.
2. Check parts and components against the packing list.
3. After charging, ensure sampler will power up and that the main
screen is operational.
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
4. The sampler may arrive with a default flow rate of 16.7 Lpm. If
during the initial verification, the sampler's target flow rate is
displayed as 16.7 Lpm, it must be changed to 15 Lpm. Proceed
directly to the calibration section of the SOP for direction in making
the change.
5. The ERG Cr+6 Filter Holder Modules will arrive to the field office in
a cooler with frozen ice substitutes. The modules will have
paperwork designating them for a specific site and run day. The
modules must be kept in a freezer prior to sampling. During
transport to the monitoring site for run preparation, the filters must
be kept cold as well. Samples must be returned to ERG cold
using ice substitutes.
C. Verification
NOTE: THE PQ100 DOES NOT REQUIRE A LEAK TEST. CUTTING
OFF THE FLOW OF AIR BY COVERING OR RESTRICTING THE AIR
FLOW TO THE INLET WILL CAUSE DAMAGE TO THE INTERNAL
PUMP AND WILL VOID THE WARRANTY.
To VERIFY flow:
1. Install a test ERG Cr+6 filter holder module if available. If a test
module is not available, the module to be used for the next sample
day is acceptable; however, the module must be used immediately
following the verification/calibration.
2. Attach a NIST traceable flow standard to the inlet of the filter
module. Ensure the flow standard is on and has equilibrated to
ambient conditions.
3. Turn on the PQ167R by pushing the "ON/OFF" button. If a
message is blinking on the display, press "ENTER" to proceed to
the "MAIN IDLE DISPLAY".
The screen display should read:
ETOOOOMin TSOO.OOM (Date)
Q(Flow)Lpm T(Time) Bty(Capacity)%
(Date) -today's date in military notation; e.g., 01JAN= January 1st
(Flow) - the current flow rate selected to be regulated.
(Time)-military time; e.g., 13:08= 13 Hours 8 Minutes or 1:08 PM
(Capacity) - remaining charge in the internal battery.
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
4. Press SETUP three times until the Set START DATE and TIME
screen appears: The screen should appear as below:
Set START DATE and TIME
(Date) (Time) Off
5. The word, "Off, should be displayed in the lower right corner of the
screen. The bottom line of the display should be flashing. If "On" is
displayed, press the "ENTER" button until "On" stops flashing.
Then toggle to "Off" by pressing the + or- buttons.
6. Press the "SETUP" button twice to get to the "MAIN IDLE
DISPLAY"
7. Press the "RUN/STOP" button to activate the pump.
8. Allow the pump to stabilize for at least 2 minutes.
9. If the measured flow and the flow indicated on the flow standard are
within 4%, the sampler's calibration is acceptable. If the flow is
outside 4%, the unit must be recalibrated.
10. Press the "RUN/STOP" button to turn off the pump.
D. Calibration
NOTE: THE PQ100 DOES NOT REQUIRE A LEAK TEST. CUTTING
OFF THE FLOW OF AIR BY COVERING OR RESTRICTING THE AIR
FLOW TO THE INLET WILL CAUSE DAMAGE TO THE INTERNAL
PUMP AND WILL VOID THE WARRANTY.
To CALIBRATE flow:
1. Install a test ERG Cr+6 filter holder module if available. If a test
module is not available, the module to be used for the next sample
day is acceptable; however, the module must be used immediately
following the verification/calibration.
2. Press "SETUP". The screen will read; "Select FLOW RATE"
3. From the "MAIN IDLE DISPLAY" press the "Setup" key once until
the message below appears;
Select FLOW RATE
The Target Q should read 15.0 Lpm. If it does not read 15.0 Lpm,
set TARGET FLOW RATE to 15.0 Lpm by pressing ENTER.
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
The whole number value will remain on constant while the tenths
still blink); use "+" or"-" to increase or decrease until 15 is
displayed. Press ENTER (Tenths value will now remain constant
while whole number blinks); use "+" or"-" to increase or decrease
until .0 is displayed.
4. From the "Select FLOW RATE" message screen, press both the
"Reset" key and the "Run/Stop" key simultaneously to enter the
calibration mode and the message below will appear;
CALIBRATE Target=15.0 Lpm
5. Press the "RUN/STOP" button to activate the pump and the
message below will appear:
CALIBRATE Target = 15.0 Lpm
Reference Q.. XX.X
The Reference Q is an approximate flow rate used only as a visual
aid in finding the corrected flow on the calibration device. This value
may indicate 5 to 15% error. This is for reference only!
6. Use the "+/-" keys to move the pump speed up or down until the
calibration device indicates the desired flow rate.
7. When a stable reading has been achieved, press the "ENTER" key
to store the flow rate.
8. Exit the Setup menu and return to the "MAIN IDLE DISPLAY".
CALIBRATIONS ARE NOT AFFECTED UNTIL THE ENTER KEY
IS PRESSED AND THE PUMP IS RUNNING.
9. Record pre- and post- flow measurements and adjustments in the
logbook.
E. Conducting the Sampling Event
Site Arrival Daily Activities
1. Visually inspect and ensure all 0-rings are in place and secure.
Replace if necessary.
2. Always ensure that samples and unused ERG Cr+6 Filter Holder
Modules are transported to and from the site cold.
3. Confirm all cables (electrical connections) are secure, and that
exterior connections are protected from the elements.
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
4. Record activities, site observations, and maintenance activities in
logbook.
Preparing Sampler for a Sampling Event
1. Prepare sample paperwork. On the ERG AMBIENT HEXAVALENT
CHROMIUM DATA SHEET, complete the "Lab Pre-Samp." and
"Field Setup" sections. Record any pertinent observations in the
notes section at the bottom of the form.
2. Turn on the PQ167R by pushing the "ON/OFF" button. If a
message is blinking on the display, press "ENTER" to proceed to
the "MAIN IDLE DISPLAY". Then press "RESET" to clear prior run
data.
3. Conduct an initial flow check (verification) by following the
instructions in section C. Verification. Record the measurement
from the flow standard on the ERG AMBIENT HEXAVALENT
CHROMIUM DATA SHEET under the "Field Setup" section on the
"Initial Rotameter Setting".
4. Following the flow check, the screen display should read:
ETOOOOMin TSOO.OOM (Date)
Q(Flow)Lpm T(Time) Bty(Capacity)%
(Date) -today's date in military notation; e.g., 01JAN= January 1st
(Flow) - the current flow rate selected to be regulated.
(Time)-military time; e.g., 13:08= 13 Hours 8 Minutes or 1:08 PM
(Capacity) - remaining charge in the internal battery.
5. Press "SETUP". The screen will read; "Select FLOW RATE"
The flow rate value will be blinking.
6. The flow rate should read 15.0 Lpm. If it does not read 15.0
Lpm, the unit must be calibrated to 15.0 Lpm. See calibration
section for adjusting target flow rate and calibration.
7. Press "SETUP". This is the date and time screen.
The screen should read;
Set DATE and TIME
(dd) (mmm) (yyyy) (time)
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
To change the Date and Time;
TIP: Only the field not blinking can be adjusted. Push enter to
move to the next field.
a. DAY: Press ENTER and change by pressing the + or - key.
When the day is correct, press ENTER.
b. MONTH: To change, press + or - key. When correct, press
ENTER.
c. YEAR: To change, press + or - key. When correct, press
ENTER.
d. TIME (hrs): To change, press + or - key. When correct, press
ENTER.
e. TIME (min): To change, press + or - key. When correct, press
ENTER.
8. When date and time are correct press "SETUP"
9. This is the sample start screen which reads;
Set START DATE and TIME
(dd)(mmm) 00:00 Off
This screen allows you to set a start date and time for a sampling
run. The default is set to midnight the next day. To designate your
own start date and time:
a. DAY: Press ENTER and change by pressing the + or - key.
When the day is correct, press ENTER.
b. MONTH: To change, press + or - key. When correct, press
ENTER.
c. YEAR: To change, press + or - key. When correct, press
ENTER.
d. TIME (hrs): To change, press + or - key. When correct, press
ENTER.
e. TIME (min): To change, press + or - key. When correct, press
ENTER.
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
f. Enable the run by setting the "On/Off" function on the screen to
"On".
WARNING: The sampler will not automatically activate if
this option is set to "Off".
10. Press "SETUP"
The screen will read;
Set RUN TIME
Hours: 24 Min: 00 On
Set to 24 hours 0 minutes. The default is always 24 hrs 0 min, the
required sample duration. If the sample time needs to be modified,
adjust as instructed in step 6 and 8.
11. Press "SETUP". The screen will return to the "MAIN IDLE
DISPLAY"
WARNING: DO NOT PRESS THE RESET BUTTON AT THIS
TIME AS THE START TIME AND RUN TIME WILL DEFAULT.
12. Press "RUN/STOP"
If the START TIME ENABLE is set to "On" then the message
"Alarm Triggered Run..."followed by "PQ100 Powering Down.."will
appear briefly. The PQ100 is now waiting for the internal real time
clock to achieve the designated start time and will then power itself
on and begin the sampling run. If the START TIME ENABLE is set
to "Off" then the pump will begin to run immediately. If this occurs,
press RUN/STOP and begin back at step 2 ensuring START TIME
ENABLE is set to "On".
Installing the ERG Cr+6 Filter Holder Module
NOTE: Gloves must be changed for each sample, i.e. between
retrieving a sample and preparing a new run gloves MUST be
changed to prevent cross contamination.
1. Remove the sample inlet cover on the stainless steel probe and
make sure there is no contamination on the probe.
2. Put on a clean pair of powderfree gloves
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
3. Take the ERG Cr+6 Filter Holder Module storage container from the
cooler and carefully remove the module. The module may be in a
plastic bag. Return the bag to the container for use in the collection
procedure.
4. Make sure the glass funnel is securely attached to the filter holder.
Loosen the small top nut on the filter container. Arrows will be
present on the filter holder showing air flow direction and they
should always point to the end of the sample probe line.
5. Holding the module with the glass funnel facing down, slide the
probe into the top fitting of the filter module and tighten the nut.
Tighten the nut until the ERG Cr+6 Filter Holder Module is securely
fastened to the probe. Do not overtighten the plastic nut.
NOTE: If running a field blank, repeat steps 1 through 5, count
to 10, and then remove the field blank filter holder module and
place it back into the antistatic bag. Label the bag to designate
the filter module as a field blank. Log the filter ID as field blank
in the comments section of the ERG Hexavalent Chromium
Sample Data Sheet. The field blank must be run before the
sample filter module is fastened to the probe.
Sample Recovery and Data Collection
NOTE: Gloves must be changed for each sample, i.e. between
retrieving a sample and preparing a new run, gloves MUST be
changed to prevent cross contamination.
1. On the ERG AMBIENT HEXAVALENT CHROMIUM DATA SHEET,
fill in the "Field Recovery" section. Be sure to fill in the "Recovery
Date", "Recovery Time", "Elapsed Time" (ETXXXXMin from
sampler), and circle a "Status" selection. This information will be on
the "MAIN STATUS SCREEN".
2. Conduct a final flow check (verification) by following the
instructions in section C. Verification. Record the measurement
from the flow standard on the ERG AMBIENT HEXAVALENT
CHROMIUM DATA SHEET under the "Field Setup" section, "Final
Rotameter Reading".
3. Put on a clean pair of powderfree gloves
4. Take the module storage container from the cooler, open, and set
aside.
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
5. While holding the ERG Cr+6 Filter Holder Module, loosen the top
nut holding the module to the sample inlet and slide the module off
the stainless steel probe.
6. Place the ERG Cr+6 Filter Holder Module including glass funnel in
the plastic bag and place back into the storage container. Place the
storage container into a cooler with ice substitutes.
7. Place cover back on end of probe line.
8. Data may be downloaded to a laptop using the PQ100/200
DOWNLOAD SOFTWARE. ERG does not require this data, but
direction can be found in the BGI PQ167 Quick Start document,
pages 16 and 17.
Sample Shipping
The ERG Cr+6 Filter Holder Module container must be packed in a cooler
with ice substitutes and shipped overnight cold to ERG. The sample
paperwork must be included in the shipment. Use the pre-filled out
FedEx label provided by ERG, and fill out the "Sender" section with the
sampling agency's address and phone number. Send priority overnight
to ERG.
If the shipping form is lost, use the address below for shipping to ERG,
and contact them directly for the FedEx accounting.
Address: ERG
601 Keystone Park Drive
Suite 700
Morrisville, NC 27560
919-468-7924
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
IV. QUALITY ASSURANCE
To ensure that quality data is being collected the following checks should be
considered:
A. Flow Calibration
A flow verification must be completed at the beginning of the study
period. If the verification does not compare within 4%, the flow must be
calibrated. Document all quality assurance activities in the logbook.
B. Flow Verifications
The flow must be verified or checked at the beginning and end of the
sampling event to determine an average sample flow. Document all
quality assurance activities and observations in the logbook.
C. Independent Audits
If possible, it is recommended that an independent flow check of the
sampler be conducted at some point during the study. This check may
be conducted by a state or local agency's quality assurance team or
independent audit program.
V. DATA FORMS
All sample related run data forms will be supplied by ERG. Check the data
sheets for completion after every setup or retrieval event. The operator is
expected to keep a logbook to document all site activities, quality assurance
activities, and sampling activities. The ERG AMBIENT HEXAVALENT
CHROMIUM DATA SHEET is attached below.
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Toxics in Schools, Hexavalent Chromium SOP
July 30, 2009
ERG Ambient Hexavalent Chromium Sample Data Sheet
ERG Lab ID #
AMBIENT HEXAVALENT CHROMIUM DATA SHEET
O)
£
Q.
Site Code:
City/State:
AQS Code:
Collection Date:
Primary Event (Y/N):
Collocated Event (Y/N):
Q,
I
OT
Site Operator:
Set-Up Date:
Collection Date:
Batch I.D. No.:
System #:
Elapsed Timer Reset (Y/N):
Initial Rotameter Setting (C.O. B.):
Programmed Start Time:
(After 5 minutes warm-up)
Programmed End Time:
t
•o «
"5 o
11 g
cc
Recovery Date:
Final Rotameter Reading (C.O.B.):
Elapsed Time:
Recovery Time:
Status:
_(After 5 minutes warm-up)
Valid Void (Circle one)
I
O
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