April 2003
Environmental Technology
Verification Report
Orbeco-Hellige
Mini-Analyst Model 942-032
Prepared by
Battelle
Battelle
. . . Putting Technology To Work
Under a cooperative agreement with
SEPA U.S. Environmental Protection Agency
ETV ElV ElV

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April 2003
Environmental Technology Verification
Report
ETV Advanced Monitoring Systems Center
Orbeco-Hellige
Mini-Analyst Model 942-032
by
Ryan James
Amy Dindal
Zachary Willenberg
Karen Riggs
Battelle
Columbus, Ohio 43201

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Notice
The U.S. Environmental Protection Agency (EPA), through its Office of Research and
Development, has financially supported and collaborated in the extramural program described
here. This document has been peer reviewed by the Agency. Mention of trade names or
commercial products does not constitute endorsement or recommendation by the EPA for use.
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
nation's air, water, and land resources. Under a mandate of national environmental laws, the
Agency strives to formulate and implement actions leading to a compatible balance between
human activities and the ability of natural systems to support and nurture life. To meet this
mandate, the EPA's Office of Research and Development provides data and science support that
can be used to solve environmental problems and to build the scientific knowledge base needed
to manage our ecological resources wisely, to understand how pollutants affect our health, and to
prevent or reduce environmental risks.
The Environmental Technology Verification (ETV) Program has been established by the EPA to
verify the performance characteristics of innovative environmental technology across all media
and to report this objective information to permitters, buyers, and users of the technology, thus
substantially accelerating the entrance of new environmental technologies into the marketplace.
Verification organizations oversee and report verification activities based on testing and quality
assurance protocols developed with input from major stakeholders and customer groups
associated with the technology area. ETV consists of seven environmental technology centers.
Information about each of these centers can be found on the Internet at http://www.epa.gov/etv/.
Effective verifications of monitoring technologies are needed to assess environmental quality
and to supply cost and performance data to select the most appropriate technology for that
assessment. In 1997, through a competitive cooperative agreement, Battelle was awarded EPA
funding and support to plan, coordinate, and conduct such verification tests for "Advanced
Monitoring Systems for Air, Water, and Soil" and report the results to the community at large.
Battelle conducted this verification under a follow-on to the original cooperative agreement.
Information concerning this specific environmental technology area can be found on the Internet
at http://www.epa.gov/etv/centers/centerl .html.
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Acknowledgments
The authors wish to acknowledge the support of all those who helped plan and conduct the
verification test, analyze the data, and prepare this report. We would like to thank Billy Potter,
U.S. EPA, National Exposure Research Laboratory; Ricardo DeLeon, Metropolitan Water
District of Southern California; William Burrows, U.S. Army Center for Environmental Health
Research; and Kenneth Wood, Du Pont Corporate Environmental Engineering Group, for their
technical review of the test/QA plan and for their careful review of this verification report. We
also would like to thank Allan Chouinard, City of Montpelier, VT; Gordon Brand, Des Moines,
IA, Water Works; Wylie Harper, City of Seattle, WA; John Morrill, City of Tallahassee, FL; and
Tom Scott, City of Flagstaff, AZ, water distribution facilities who provided post-treatment water
samples for evaluation.
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Contents
Page
Notice	ii
Foreword 	 iii
Acknowledgments 	 iv
List of Abbreviations 	 viii
1	Background 	 1
2	Technology Description 	2
3	Test Design and Procedures 	4
3.1	Introduction	4
3.2	Reference Method	5
3.3	Test Design 	5
3.4	Test Samples 	6
3.4.1	Quality Control Samples 	6
3.4.2	Performance Test Samples	8
3.4.3	Lethal/Near-Lethal Concentrations of Cyanide in Water	8
3.4.4	Surface Water; Drinking Water from Around the U.S.; and
Columbus, OH, Area Drinking Water	8
3.5	Test Procedure	 11
3.5.1	Sample Preparation 	 11
3.5.2	Sample Identification	 11
3.5.3	Sample Analysis	 12
4	Quality Assurance/Quality Control	 13
4.1	Reference Method QC Results	 13
4.2	Audits 	 16
4.2.1	Performance Evaluation Audit		16
4.2.2	Technical Systems Audit		16
4.2.3	Audit of Data Quality		17
4.3	QA/QC Reporting 		17
4.4	Data Review 		17
5	Statistical Methods and Reported Parameters	 19
5.1	Accuracy		19
5.2	Precision 		19
5.3	Linearity 	20
5.4	Method Detection Limit. 	20
5.5	Inter-Unit Reproducibility	20
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5.6	Lethal or Near-Lethal Dose Response	20
5.7	Operator Bias	21
5.8	Field Portability	21
5.9	Ease of Use 	21
5.10	Sample Throughput	21
6	Test Results	22
6.1	Accuracy	22
6.2	Precision 	31
6.3	Linearity 	32
6.4	Method Detection Limit 	34
6.5	Inter-Unit Reproducibility	34
6.6	Lethal or Near-Lethal Dose Response	35
6.7	Operator Bias	36
6.8	Field Portability	37
6.9	Ease of Use 	38
6.10	Sample Throughput	38
7	Performance Summary	39
8	References 	42
Figures
Figure 2-1.	Orbeco Mini-Analyst Model 942-032 Water Analyzer 	2
Figure 3-1.	Sampling Through Analysis Process 		10
Figure 6-1.	Non-Technical Operator Linearity Results	33
Figure 6-2.	Technical Operator Linearity Results	33
Figure 6-3.	Inter-Unit Reproducibility Results	35
Figure 6-4.	Non-Technical vs. Technical Operator Bias Results 	36
Tables
Table 3-1. Test Samples 	7
Table 4-1. Reference Method QCS Results	 14
Table 4-2. Reference Method LFM Analysis Results 	 15
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Table 4-3.	Summary of Performance Evaluation Audit 	 16
Table 4-4.	Summary of Data Recording Process	 18
Table 6-la.	Cyanide Results from Performance Test Samples 	23
Table 6-lb.	Cyanide Results from Surface Water	24
Table 6-lc.	Cyanide Results from U.S. Drinking Water	25
Table 6-Id.	Cyanide Results from Columbus, OH, Drinking Water	27
Table 6-2a.	Percent Accuracy of Performance Test Sample Measurements 	29
Table 6-2b.	Percent Accuracy of Surface Water Measurements 	30
Table 6-2c.	Percent Accuracy of U.S. Drinking Water Measurements	30
Table 6-2d.	Percent Accuracy of Columbus, OH, Drinking Water Measurements	30
Table 6-3a.	Relative Standard Deviation of Performance Test Sample Measurements	31
Table 6-3b.	Relative Standard Deviation of Surface Water Measurements	31
Table 6-3c.	Relative Standard Deviation of U.S. Drinking Water Measurements	32
Table 6-3d.	Relative Standard Deviation of Columbus, OH,
Drinking Water Measurements	32
Table 6-4.	Results of Method Detection Limit Assessment 	34
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List of Abbreviations
AMS
Advanced Monitoring Systems
ASTM
American Society of Testing and Materials
ATEL
Aqua Tech Environmental Laboratories
DPD
n,n-diethyl-p-phenylenediamine
EPA
U.S. Environmental Protection Agency
ETV
Environmental Technology Verification
HC1
hydrochloric acid
HCN
hydrogen cyanide
ID
identification
KCN
potassium cyanide
L
liter
LFM
laboratory-fortified matrix
MDL
method detection limit
mg
milligram
NaOH
sodium hydroxide
PE
performance evaluation
PT
performance test
QA
quality assurance
QA/QC
quality assurance/quality control
QC
quality control
QCS
quality control standard
QMP
Quality Management Plan
RB
reagent blank
RPD
relative percent difference
RSD
relative standard deviation
TSA
technical systems audit
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Chapter 1
Background
The U.S. Environmental Protection Agency (EPA) supports the Environmental Technology
Verification (ETV) Program to facilitate the deployment of innovative environmental tech
nologies through performance verification and dissemination of information. The goal of the
ETV Program is to further environmental protection by substantially accelerating the acceptance
and use of improved and cost-effective technologies. ETV seeks to achieve this goal by provid
ing high-quality, peer-reviewed data on technology performance to those involved in the design,
distribution, financing, permitting, purchase, and use of environmental technologies.
ETV works in partnership with recognized testing organizations; with stakeholder groups
consisting of buyers, vendor organizations, and permitters; and with the full participation of
individual technology developers. The program evaluates the performance of innovative tech
nologies by developing test plans that are responsive to the needs of stakeholders, conducting
field or laboratory tests (as appropriate), collecting and analyzing data, and preparing peer-
reviewed reports. All evaluations are conducted in accordance with rigorous quality assurance
(QA) protocols to ensure that data of known and adequate quality are generated and that the
results are defensible.
The EPA's National Exposure Research Laboratory and its verification organization partner,
Battelle, operate the Advanced Monitoring Systems (AMS) Center under ETV. The AMS Center
recently evaluated the performance of the Orbeco Mini-Analyst Model 942-032 in detecting the
presence of cyanide in water. Portable cyanide analyzers were identified as a priority technology
verification category through the AMS Center stakeholder process.
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Chapter 2
Technology Description
The objective of the ETV AMS Center is to verify the performance characteristics of
environmental monitoring technologies for air, water, and soil. This verification report provides
results for the verification testing of the Orbeco Mini-Analyst Model 942-032. Following is a
description of the Orbeco Mini-Analyst Model 942-032 based on information provided by the
vendor. The information provided below was not verified in this test.
The Orbeco Mini-Analyst Model 942-032 is a portable colorimeter in which a sample and a
reagent are mixed and analyzed photometrically to provide a quantitative determination of
cyanide in the sample. The Orbeco Mini-Analyst Model 942-032 uses a photodiode detector,
and results are reported on a liquid crystal display. Permanent calibrations for the tests are stored
in the microprocessor memory. The Orbeco Mini-Analyst Model 942-032 comes with a hard
cover carrying case, reagents for 50 samples, pH adjustment and dechlorination reagents, and
four reaction vials. The detectable range of cyanide using the Orbeco Mini-Analyst Model
942-032 is 0 to 0.400 mg/L.
Figure 2-1. Orbeco Mini-Analyst
Model 942-032 Water Analyzer
First, the samples are preserved to exactly 0.020 M
sodium hydroxide (NaOH). Then, one milliliter (mL)
each of the buffer and 1.75 M hydrochloric acid (HCl),
provided by Orbeco, are added to 100 mL of preserved
sample. The pH is then adjusted to be within 6 to 7, as
necessaiy. A capsule of powdered reagent is added to a
10.0-mL aliquot of the pH-adjustcd sample, and the
sample vial is shaken and set aside for two minutes. In
the meantime, a liquid reagent solution is made up in a
separate 25-mL vial. At the appropriate time, this
reagent is added to the original sample vial, and the
vial is shaken. After a 15-minute color development
period, the sample is placed into the Orbeco Mini-
Analyst Model 942-032, and a cyanide concentration
is displayed in micrograms per liter; however, for
consistency with the reference laboratory results, all
data within this report have been converted to
milligrams per liter (mg/L). The dimensions of the
Orbeco Mini-Analyst Model 942-032 are 6 x 4 x 2
inches, and it weighs 340 grams (12 ounces). The
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Orbeco Mini-Analyst Model 942-032 operates on four AA batteries and comes with four sample
tubes. The list price for this unit is $299.00 for the colorimeter and $67.50 for reagents adequate
for approximately 50 water samples.
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Chapter 3
Test Design and Procedures
3.1 Introduction
Cyanide can be present in various forms in water. This verification test focuses on the detection
of the free cyanide ion prepared using potassium cyanide (KCN) and referred to as simply
"cyanide" in this report. At high doses, this form of cyanide inhibits cellular respiration and, in
some cases, can result in death. Because of the toxicity of cyanide to humans, the EPA has set
0.200 mg/L as the maximum concentration of cyanide that can be present in drinking water. In
drinking and surface water under ambient conditions, cyanide evolves from aqueous hydrogen
cyanide (HCN), sodium cyanide, KCN, and other metal or ionic salts where cyanide is released
when dissolved in water. Heavier cyanide complexes (e.g., iron) are bound tightly, requiring an
acid distillation to liberate the toxic free cyanide ion, a step not verified as part of this test, since
field portability would have been eliminated. Because disassociation of the free cyanide ion is
unlikely under ambient conditions, the heavier complexes are considered much less toxic than
simple cyanide salts such as potassium and sodium cyanide.
This verification test was conducted according to procedures specified in the Test/QA Plan for
Verification of Portable Analyzers for Detection of Cyanide in Water.(1) The verification was
based on comparing the cyanide concentrations of water samples analyzed using the Orbeco
Mini-Analyst Model 942-032 with cyanide concentrations analyzed using a laboratory-based
reference method. The reference method used during this verification test was EPA Method
335.1, Cyanides Amenable to ChlorinationP This method was selected because it measures the
concentration of the cyanide ion in water samples under ambient conditions, which is the same
form of cyanide that the participating technologies are designed to measure. The Orbeco Mini-
Analyst Model 942-032 was verified by analyzing performance test (PT), surface, and drinking
water samples. A statistical comparison of the analytical results from the Orbeco Mini-Analyst
Model 942-032 and the reference method provided the basis for the quantitative performance
evaluations.
The Orbeco Mini-Analyst Model 942-032's performance was evaluated in terms of
¦	Accuracy
¦	Precision
¦	Linearity
¦	Method detection limit
¦	Inter-unit reproducibility
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¦	Lethal or near-lethal dose response
¦	Operator bias
¦	Field portability
¦	Ease of use
¦	Sample throughput.
3.2 Reference Method
Aqua Tech Environmental Laboratories (ATEL) in Marion, OH, performed the reference
analyses of all test samples. ATEL received the samples from Battelle labeled with an identifica-
tion number meaningful only to Battelle, performed the analyses, and submitted to Battelle the
results of the analyses without knowledge of the prepared or fortified concentration of the
samples.
The analytical results for the Orbeco Mini-Analyst Model 942-032 were compared with the
results obtained from analysis using semi-automated colorimetry according to EPA Method
335. l.(2) For the reference method analyses, the concentration of free cyanide was determined by
the difference of two measurements of total cyanide. One colorimetric determination was made
after the free cyanide in the sample had been chlorinated to cyanogen chloride, which degrades
quickly, and a second was made without chlorination. Typically, samples were sent to the
reference laboratory for analysis each testing day. The reference analysis was performed within
14 days of sample collection.
3.3 Test Design
Two Orbeco Mini-Analyst Model 942-032s were tested independently between January 13 and
February 4, 2003. All preparation and analyses were performed according to the manufacturer's
recommended procedures for the Orbeco Mini-Analyst Model 932-032. The verification test
involved challenging the Orbeco Mini-Analyst Model 942-032 with a variety of test samples,
including sets of drinking and surface water samples representative of those likely to be
analyzed by the Orbeco Mini-Analyst Model 942-032. The results from the Orbeco Mini-
Analyst Model 942-032 were compared with the reference method to quantitatively assess
accuracy and linearity. Multiple aliquots of each test sample were analyzed separately to assess
the precision of the Orbeco Mini-Analyst Model 942-032 and the reference method.
The Orbeco Mini-Analyst Model 942-032 was tested by a technical and a non-technical operator
to assess operator bias. The non-technical operator had no previous laboratory experience. Both
operators received a brief orientation with a vendor representative to become acquainted with
the basic operation of the instrument. Both operators analyzed all of the test samples. Each
operator manipulated the water samples and reagents to generate a solution that could be probed
photometrically. Then, each operator analyzed that solution using both Orbeco Mini-Analyst
Model 942-032s.
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Sample throughput was estimated based on the time required to prepare and analyze a sample.
Ease of use was based on documented observations by the operators and the Battelle Verification
Test Coordinator. The Orbeco Mini-Analyst Model 942-032 was used in a field environment as
well as in a laboratory setting to assess the impact of field conditions on performance.
3.4 Test Samples
Test samples used in the verification test included quality control (QC) samples, PT samples,
lethal/near-lethal concentration samples, drinking water samples, and surface water samples
(Table 3-1). The QC, PT, and lethal/near-lethal samples were prepared from purchased standards.
The PT and QC sample concentrations were targeted to the EPA maximum contaminant level in
drinking water, which for cyanide is 0.200 mg/L.(3) The PT samples ranged from 0.030 mg/L to
0.800 mg/L. The performance of the Orbeco Mini-Analyst Model 942-032 also was qualitatively
evaluated with samples prepared in American Society of Testing and Materials (ASTM) Type II
deionized water with cyanide concentrations up to 250 mg/L that could be lethal if ingested. Two
surface water sources (Olentangy River and Alum Creek Reservoir) were sampled and analyzed.
In addition, five sources of drinking water from around the United States and two sources of
Columbus, OH, drinking water were evaluated (Table 3-1).
3.4.1 Quality Control Samples
Prepared QC samples included both laboratory reagent blanks (RBs) and laboratory-fortified
matrix (LFM) samples (Table 3-1). The RB samples were prepared from ASTM Type II deionized
water and were exposed to handling and analysis procedures identical to other prepared samples,
including the addition of all reagents. These samples were used to help ensure that no sources of
contamination were introduced in the sample handling and analysis procedures. One reagent
blank sample was analyzed for every batch of about 12 water samples. The LFM samples were
prepared as aliquots of drinking and surface water samples spiked with KCN as free cyanide to
increase the cyanide concentration by 0.200 mg/L. Four LFM samples were analyzed for each
source of water. These samples were used to monitor the general performance of the reference
method to help determine whether matrix effects had an influence on the analytical results.
Quality control standards (QCSs) were used to ensure the proper calibration of the reference
instrument. The reference laboratory prepared the QCSs for its use from a stock solution inde
pendent from the one used to prepare the QCS analyzed using the Orbeco Mini-Analyst Model
942-032. The QCSs were purchased by Battelle from a commercial supplier and subject only to
dilution as appropriate. An additional independent QCS was used in a performance evaluation
(PE) audit of the reference method.
The reference method required that the concentration of each QCS be within 25% of the known
concentration. If the difference was larger that 25%, the data collected since the most recent QCS
were flagged; and proper maintenance was performed to regain accurate cyanide measurement,
according to ATEL's protocols. Section 4.1 describes these samples in more detail.
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Table 3-1. Test Samples
Type of Sample
Sample Characteristics
Concentration
No. of Samples
Quality Control
RB
~0
10% of all
LFM
0.200 mg/L
4 per water
source (also
listed below)
QCS
0.200 mg/L
10% of all
Performance Test
For the determination of
method detection limit
0.010 mg/L
7
Cyanide
0.030 mg/L
4
Cyanide
0.100 mg/L
4
Cyanide
0.200 mg/L
4
Cyanide
0.400 mg/L
4
Cyanide
0.800 mg/L
4
Lethal /
Near-Lethal
Cyanide
50.0 mg/L
4
Cyanide
100 mg/L
4
Cyanide
250 mg/L
4
Surface Water
Alum Creek Reservoir
Background
4
0.200 mg/L LFM
4
Olentangy River
Background
4
0.200 mg/L LFM
4
Drinking Water
from Around the
U.S.
Northwestern U.S.
Background
1
0.200 mg/L LFM
4
Southwestern U.S.
Background
400
0.200 mg/L LFM
4
Midwestern U.S.
Background
400
0.200 mg/L LFM
4
Southeastern U.S.
Background
4W
0.200 mg/L LFM
4
Northeastern U.S.
Background
1
0.200 mg/L LFM
4
Columbus, OH,
Area Drinking
Water
Residence with city water
Background
6
0.200 mg/L LFM
12
Residence with well water
Background
6
0.200 mg/L LFM
12
(a) Because the initial aliquot analyzed by the non-technical operator resulted in non-detectable concentrations of
cyanide, the non-technical operator did not analyze additional aliquots. However, the results for the initial aliquots
analyzed by the technical operator were other than a non-detectable concentration, so three more aliquots were
analyzed.
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The Orbeco Mini-Analyst Model 942-032 was factory calibrated, so no additional calibration
was performed by the operators. However, QCSs were analyzed (without defined performance
expectations) by the Orbeco Mini-Analyst Model 942-032 to demonstrate their proper
functioning to the operator. A QCS was analyzed before and after each sample batch (typically
consisting of 12 samples).
3.4.2	Performance Test Samples
The PT samples (Table 3-1) were prepared in the laboratory using ASTM Type II deionized
water. The samples were used to determine the Orbeco Mini-Analyst Model 942-032's accuracy,
linearity, and detection limit. Seven non-consecutive replicate analyses of 0.010 mg/L solution
were made to obtain precision data with which to determine the method detection limit
(MDL).(4) Four other solutions were prepared to assess the linearity over a 0.030- to 0.800-mg/L
range of cyanide concentrations. Four aliquots of each of these solutions were analyzed
separately to assess the precision of the Orbeco Mini-Analyst Model 942-032. The
concentrations of the PT samples are listed in Table 3-1. The operators analyzed the PT samples
blindly and in random order to minimize bias.
3.4.3	Lethal/Near-Lethal Concentrations of Cyanide in Water
To assess the response of the Orbeco Mini-Analyst Model 942-032 when cyanide is present in
drinking water at lethal and near-lethal concentrations (>50.0 mg/L), samples were prepared in
ASTM water at concentrations of 50.0, 100, and 250 mg/L. Qualitative observations were made
of the Orbeco Mini-Analyst Model 942-032 while analyzing such samples. Observations of
unusual operational characteristics (rate of color change, unusually intense color, unique digital
readout, etc.) were documented.
3.4.4	Surface Water; Drinking Water from Around the U.S.; and Columbus, OH, Area
Drinking Water
Water samples, including fresh surface water and tap water (well and local distribution sources)
were collected from a variety of sources and used to evaluate technology performance. Surface
water samples were collected from
¦	Alum Creek Reservoir (OH)
¦	Olentangy River (OH).
Drinking water samples were collected from
¦	Local distribution source water (post-treatment) from five cities (Montpelier, VT;
Des Moines, IA; Seattle, WA; Tallahassee, FL; and Flagstaff, AZ)
¦	Columbus, OH, city water
¦	Columbus, OH, well water.
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The water samples collected as part of this verification test were not characterized in any way
(i.e., hardness, alkalinity, etc.) other than for cyanide concentration. Each sample was tested for
the presence of chlorine, dechlorinated if necessary, preserved with NaOH to a pH greater than
12, and split into two subsamples. Figure 3-1 is a diagram of the process leading from sampling
to aliquot analysis. One subsample was spiked with 0.200 mg/L of cyanide to provide LFM
aliquots, and the other subsample remained unspiked (background). Four 10.0-mL aliquots were
taken from each subsample and analyzed for cyanide by the Orbeco Mini-Analyst Model 942-
032. Also taken from the background subsample were eight aliquots used for analysis by the
reference method. Four of the aliquots were left unspiked and analyzed by the reference method,
and four of the aliquots were fortified with 0.200 mg/L of KCN as free cyanide at the reference
laboratory just before the reference analyses took place. This was done to closely mimic the time
elapsed between when the LFM samples were fortified with 0.200 mg/L KCN as free cyanide
and when they were analyzed during the testing of the participating technologies.
To assess the reproducibility of background water samples, all four background replicates of
Columbus, OH, city and well water were analyzed at the laboratory analysis site regardless of the
response of the first aliquot. Four LFM aliquots were prepared and analyzed for every drinking
and surface water source, regardless of the concentration of the initial aliquot. To avoid repli-
cating non-detectable concentrations of cyanide, only one background aliquot of each source of
drinking water was analyzed if cyanide was not detectable in the first aliquot analyzed by the
Orbeco Mini-Analyst Model 942-032. If cyanide was detectable in that initial aliquot, three
additional aliquots of that sample were analyzed in addition to four LFM aliquots.
Surface water from the Olentangy River and Alum Creek Reservoir and drinking water samples
collected at the five U.S. cities were shipped to Battelle for use in verification testing. Surface
water was collected near the shoreline by submerging containers no more than one inch below
the surface of the water. Representatives of each city's water treatment facility provided Battelle
a sample of water that had completed the water treatment process, but had not yet entered the
water distribution system. When the samples arrived at Battelle, they were dechlorinated,
preserved, and split into background and LFM subsamples as described above for the rest of the
water samples.
Columbus, OH, city and well water samples were used to verify the field portability of the
Orbeco Mini-Analyst Model 942-032. Approximately 20 liters of water were collected from an
outside spigot at two participating residences, one with well water and one with Columbus, OH,
city water, and split into three samples. One sample was analyzed outdoors at the residence
under the current weather conditions. The weather conditions on the two days of outdoor testing
happened to be extremely cold (air temperature ~0°C, sample temperature ~4 to 6°C). A second
sample was equilibrated to room temperature inside the residence (~17°C) and analyzed inside
the residence. These two samples were preserved, split into background and LFM samples, and
analyzed at the field location as described for the other water samples (see Figure 3-1). For the
third sample, the background and LFM samples were prepared at the field location and trans-
ported to Battelle for analysis in the laboratory two to three days later. Because these analyses
were done using the same bulk water sample, a single set of four background replicates was
analyzed using the reference method. The LFM sample fortified at the field location and the
LFM
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Analyze
four
aliquots by
reference
method
(background)
Spike four
aliquots with
0.2 mg/L
cyanide
at reference
laboratory
Background
Subsample
LFM
Subsample
Water
Sample
Dechlorinate
Test for
Chlorine
Preserve
with NaOH
to pH > 12
Spike four
aliquots with
0.2 mg/L
cyanide
Analyze by
reference
method
(LFM)
Adjust pH
of four
aliquots
with HCI
to between
6 and 7
Adjust pH
of four
aliquots
with HCI
to between
6 and 7
Analyze
aliquots
by portable
cyanide
analyzer
(background)
Analyze four
10-mL aliquots
by portable
cyanide
analyzer
(LFM)
Figure 3-1. Sampling Through Analysis Process
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sample fortified at the reference laboratory were analyzed by the reference method (see
Table 4-2). These background and LFM reference concentrations were compared with the results
produced by the Orbeco Mini-Analyst Model 942-032 at the indoor and outdoor field locations
and the laboratory location.
3.5 Test Procedure
3.5.1	Sample Preparation
QC and PT samples were prepared from a commercially available National Institute of
Standards and Technology-traceable standard. The standard was dissolved and diluted to
appropriate concentrations using ASTM Type II deionized water in Class A volumetric
glassware. The QC and PT samples were prepared at the start of testing, preserved with NaOH,
and stored at 4°C for the duration of the test.
Surface and drinking water samples were collected from the sources indicated in Section 3.4.4
and were stored in high-density polyethylene containers. Because free chlorine degrades cyanide
during storage, at the time of sample receipt, before NaOH preservation, all of the samples were
tested for free chlorine with potassium iodide starch paper. When the samples collected as part
of this verification test were tested in this manner, none of them changed the color of the paper,
indicating that free chlorine was not present. However, when the LFM samples were analyzed
with the colorimetic technologies being verified, non-detectable results were observed. To
further investigate the possibility of a chlorine interference, approximately 500 mL of each water
sample were added to separate beakers, and one n,n-diethyl-p-phenylenediamine (DPD) chlorine
indicator tablet (Orbeco Analytical Systems, Inc.) was added and crushed with a glass stirring
rod. If the water turned pink, the presence of chlorine was indicated, and ascorbic acid was
added a few crystals at a time until the color disappeared. All the drinking water samples were
tested in this manner; and, if the presence of chlorine was indicated, approximately 60.0 mg of
ascorbic acid were added per liter of bulk sample to dechlorinate the sample. A separate DPD
indicator test (as described above) was done to confirm adequate dechlorination of the sample
(indicated by no color change). After dechlorination, all samples to be analyzed by the Orbeco
Mini-Analyst Model 942-032 were adjusted to a pH between 6.0 and 7.0, according to the
manufacturer's specifications (see Figure 3-1). All the samples to be analyzed by the reference
method were stored at 4°C and preserved with NaOH at a pH greater than 12.0.
3.5.2	Sample Identification
Aliquots to be analyzed were drawn from the prepared standard solutions or from source and
drinking water samples and placed in uniquely identified sample containers for subsequent
analysis. The sample containers were identified by a unique identification (ID) number. A
master log of the samples and sample ID numbers for each unit being verified was kept by
Battelle. The ID number, date, person collecting, sample location, and time of collection were
recorded on a chain-of-custody form for all field samples.
11

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3.5.3 Sample Analysis
The two Orbeco Mini-Analyst Model 942-032s were tested independently. Each Orbeco Mini-
Analyst Model 942-032 analyzed the full set of samples, and verification results were compared
to assess inter-unit reproducibility. As shown in Table 3-1, the samples included replicates of
each of the PT, QC, surface water, and drinking water samples. The complete set of samples was
analyzed twice for each of the units being verified, once by a non-technical operator and once by
a technical operator. The analyses were performed according to the manufacturer's
recommended procedures.
Results were recorded manually on appropriate data sheets. In addition to the analytical results,
the data sheets included records of the time required for sample analysis and operator observa-
tions concerning the use of the Orbeco Mini-Analyst Model 942-032 (i.e., ease of use,
maintenance, etc.).
While the participating technologies were being tested, a replicate sample set was being
analyzed by the reference laboratory. The reference instrument was operated according to the
recommended procedures in the instruction manual, and samples were analyzed according to
EPA Method 335.1(2) and ATEL standard operating procedures. Results from the reference
analyses were recorded electronically and compiled by Aqua Tech into a report, including the
sample II ) and the analyte concentration for each sample.
12

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Chapter 4
Quality Assurance/Quality Control
Quality assurance/quality control (QA/QC) procedures were performed in accordance with the
quality management plan (QMP) for the AMS Center(5) and the test/QA plan for this
verification test.(1)
4.1 Reference Method QC Results
Analyses of QC samples were used to document the performance of the reference method. To
ensure that no sources of contamination were present, RB samples were analyzed. The test/QA
plan stated that, if the analysis of an RB sample indicated a concentration above the MDL for
the reference method, any contamination source was to be corrected and a proper blank reading
achieved before proceeding with the verification test. Six reagent blank samples were analyzed,
and all of them were reported as below the 0.005 mg/L reporting limit for the reference method.
The reference instrument was calibrated initially according to the procedures specified in the
reference method. The accuracy of the reference method was verified with QCS samples
analyzed with the sample sets. One of two QCS samples, one with a concentration of 0.150
mg/L and the other with a concentration of 0.200 mg/L, were analyzed with each analytical
batch (approximately every 10 water samples). As required by the test/QA plan,(1) if the QCS
analysis differed by more than 25% from the true value of the standard, corrective action would
be taken before the analysis of more samples. As shown in Table 4-1, the QCS results were
always within the acceptable percent recovery range of 75 to 125% and, in fact, were always
between 90 and 110%.
Reference LFM samples were analyzed to confirm the proper functioning of the reference
method and to assess whether matrix effects influenced the results of the reference method. The
LFM recovery (R) of the spiked solution was calculated from the following equation:
R = cs -c xiQQ
where Cs is the reference concentration of the spiked sample, C is the reference concentration of
the background sample, which, in this case, was always zero (results were below the MDL for
the
13

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Table 4-1. Reference Method QCS Results
Known QCS Concentration
Date
Analysis Result
(mg/L)
% Recovery
1/13/2003
0.157
0.150
105
1/13/2003
0.203
0.200
102
1/15/2003
0.142
0.150
95
1/15/2003
0.180
0.200
90
1/16/2003
0.151
0.150
101
1/16/2003
0.194
0.200
97
1/17/2003
0.154
0.150
103
1/17/2003
0.190
0.200
95
1/20/2003
0.190
0.200
95
1/20/2003
0.158
0.150
105
1/21/2003
0.153
0.150
102
1/21/2003
0.205
0.200
103
1/27/2003
0.143
0.150
95
1/27/2003
0.187
0.200
94
1/28/2003
0.146
0.150
97
1/28/2003
0.186
0.200
93
1/29/2003
0.149
0.150
99
1/29/2003
0.189
0.200
95
1/30/2003
0.139
0.150
93
1/30/2003
0.187
0.200
94
1/30/2003
0.139
0.150
93
1/30/2003
0.188
0.200
94
1/31/2003
0.146
0.150
97
1/31/2003
0.150
0.150
100
1/31/2003
0.196
0.200
98
2/3/2003
0.152
0.150
101
2/3/2003
0.189
0.200
95
2/5/2003
0.147
0.150
98
2/5/2003
0.149
0.150
99
2/5/2003
0.194
0.200
97
2/6/2003
0.151
0.150
101
2/6/2003
0.198
0.200
99
2/7/2003
0.154
0.150
103
2/7/2003
0.199
0.200
100
2/10/2003
0.148
0.150
99
2/10/2003
0.181
0.200
90
2/11/2003
0.141
0.150
94
2/11/2003
0.180
0.200
90
2/11/2003
0.136
0.150
91
2/11/2003
0.191
0.200
96
2/12/2003
0.159
0.150
106
2/12/2003
0.211
0.200
106
2/12/2003
0.153
0.150
102
2/12/2003
0.206
0.200
103
2/13/2003
0.158
0.150
105
14

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reference method), and s is the fortified concentration of the cyanide spike. If the percent
recovery of an LFM fell outside the range of 75 to 125%, a matrix effect or some other analytical
problem was suspected. As shown in Table 4-2, only the percent recovery for the LFM from the
Columbus, OH, well water was outside of acceptable ranges, indicating a potential matrix effect.
Table 4-2. Reference Method LFM Analysis Results
Sample Description
Fortified
Concentration
(mg/L)
Average
Reference
Concentration
(mg/L)
Average
Recovery
Reference
RSD
Alum Creek LFM
0.200
0.168
84%
8%
Olentangy River LFM
0.200
0.175
87%
2%
Des Moines, IA, LFM
0.200
0.178
89%
3%
Flagstaff, AZ, LFM
0.200
0.153
76%
12%
Montpelier, VT, LFM
0.200
0.170
85%
2%
Seattle, WA, LFM
0.200
0.173
87%
2%
Tallahassee, FL, LFM
0.200
0.161
80%
2%
Columbus, OH, City Water LFM(a)
0.200
0.172
86%
4%
Columbus, OH, City Water LFM03'
0.200
0.152
76%
1%
Columbus, OH, Well Water LFM(a)
0.200
0.107
53%
13%
Columbus, OH, Well Water LFM®
0.200
<0.005
0%
NA(c)
(a)	Reference LFM sample spiked minutes before analysis by the reference method.
(b)	Reference LFM sample spiked 8 to 10 days before analysis by the reference method.
(c)	Calculation of relative standard deviation (RSD) not appropriate for non-detectable results.
To mimic the elapsed time between fortification and analysis by the technologies being verified,
the reference LFM samples were spiked just minutes prior to analysis using the reference
method. However, because the well water LFM samples exhibited decreased cyanide
concentrations when analyzed by the vendor technologies one or two days after fortification, the
LFM samples for the Columbus, OH, city and well water spiked in the field location were also
submitted to the reference laboratory for analysis. These samples were analyzed eight to 10 days
after initial fortification. The Columbus, OH, city reference LFM result after the eight- to 10-day
delay was within 15% of the result obtained from the LFM sample spiked just minutes before
reference analysis. However, the well water reference LFM result fortified eight to 10 days prior
to analysis was less than the MDL for the reference method. The combination of the poor
recovery (53%) of cyanide obtained immediately upon spiking and the complete loss of the
reference method's ability to detect the cyanide fortified eight to 10 days before strongly
suggests the presence of a time-dependent matrix interference in the well water. In response to
this finding, the biases for the well water samples were calculated using the fortified
concentration of cyanide (0.200 mg/L) rather than the reference LFM result.
15

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4.2 Audits
4.2.1 Performance Evaluation Audit
A PE audit was conducted once to assess the quality of the reference measurements made in this
verification test. For the PE audit, an independent standard was obtained from a different vendor
than the one that supplied the QCSs. The relative percent difference (RPD) of the measured
concentration and the known concentration was calculated using the following equation:
M
RPD = — xlOO	(2)
A
where M is the absolute difference between the measured and known concentrations, and A is
the mean of the same two concentrations. An RPD of less than 25% was required for the
reference measurements to be considered acceptable. Failure to achieve this agreement would
have triggered a repeat of the PE comparison. As shown in Table 4-3, all the PE sample results
were well within this required range.
Table 4-3. Summary of Performance Evaluation Audit


Measured
Known



Concentration
Concentration
RPD
Sample
Date of Analysis
(mg/L)
(mg/L)
(%)
PE-A
2-12-2003
0.216
0.200
8
PE-B
2-12-2003
0.213
0.200
6
PE-C
2-12-2003
0.218
0.200
9
PE-D
2-12-2003
0.203
0.200
1
4.2.2 Technical Systems Audit
The Battelle Quality Manager performed a pre-verification test audit of the reference laboratory
(ATEL) to ensure that the selected laboratory was proficient in the reference analyses. This
entailed a review of the appropriate training records, state certification data, and the laboratory
QMP. The Battelle Quality Manager also conducted a technical systems audit (TSA) to ensure
that the verification test was performed in accordance with the test/QA plan(1) and the AMS
Center QMP.(5) As part of the audit, the Battelle Quality Manager reviewed the reference method
used, compared actual test procedures to those specified in the test/QA plan, and reviewed data
acquisition and handling procedures. Observations and findings from this audit were docu-
mented and submitted to the Battelle Verification Test Coordinator for response. No findings
were documented that required any corrective action. The records concerning the TSA are
permanently stored with the Battelle Quality Manager.
16

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4.2.3 Audit of Data Quality
At least 10% of the data acquired during the verification test were audited. Battelle's Quality
Manager traced the data from the initial acquisition, through reduction and statistical analysis,
to final reporting, to ensure the integrity of the reported results. All calculations performed on
the data undergoing the audit were checked.
4.3 QA/QC Reporting
Each assessment and audit was documented in accordance with Sections 3.3.4 and 3.3.5 of the
QMP for the ETV AMS Center.(5) Once the assessment report was prepared, the Battelle
Verification Test Coordinator ensured that a response was provided for each adverse finding or
potential problem and implemented any necessary follow-up corrective action. The Battelle
Quality Manager ensured that follow-up corrective action was taken. The results of the TSA
were sent to the EPA.
4.4 Data Review
Records generated in the verification test were reviewed before these records were used to
calculate, evaluate, or report verification results. Table 4-4 summarizes the types of data
recorded. The review was performed by a technical staff member involved in the verification
test, but not the staff member who originally generated the record. The person performing the
review added his/her initials and the date to a hard copy of the record being reviewed.
17

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Table 4-4. Summary of Data Recording Process
Data to be
Recorded
Responsible
Party
Where Recorded
How Often
Recorded
Disposition of Data(a)
Dates, times of test
events
Battelle
Laboratory record
books
Start/end of test; at
each change of a
test parameter
Used to organize/
check test results;
manually incorporated
data into spreadsheets
as necessary
Test parameters
(meteorological
conditions, analyte
concentrations,
location, etc.)
Battelle
Laboratory record
books
When set or
changed, or as
needed to
document stability
Used to organize/
check test results;
manually incorporated
data into spreadsheets
as necessary
Water sampling data
Battelle
Laboratory record
books
At least at the time
of sampling
Used to organize/
check test results;
manually incorporated
data into spreadsheets
as necessary
Reference method
sample analysis,
chain of custody,
results
ATEL
Laboratory record
book/data sheets or
data acquisition
system, as
appropriate
Throughout sample
handling and
analysis process
Excel spreadsheets
(a) All activities subsequent to data recording were carried out by Battelle.
18

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Chapter 5
Statistical Methods and Reported Parameters
The statistical methods presented in this chapter were used to verify the performance parameters
listed in Section 3.1.
5.1 Accuracy
Accuracy was assessed relative to the results obtained from the reference analyses. Samples were
analyzed by both the reference method and the Orbeco Mini-Analyst Model 942-032. The
results for each set of analyses were averaged, and the accuracy was expressed in terms of a
relative average bias (B) as calculated from the following equation:
where d is the average difference between the readings from the Orbeco Mini-Analyst Model
942-032 and those from the reference method, and CR is the average of the reference
measurements. Accuracy was assessed independently for each Orbeco Mini-Analyst Model 942-
032 to determine inter-unit reproducibility. Additionally, the results were analyzed
independently for the readings obtained from the two operators to determine whether significant
operator bias existed.
5.2 Precision
The standard deviation (S) of the results for the replicate samples was calculated and used as a
measure of Orbeco Mini-Analyst Model 942-032 precision at each concentration.
(3)
1/2
1 n	9
S=JZ]^~C)
_n 1 k=l
(4)
19

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where n is the number of replicate samples, Ck is the concentration measured for the kth sample,
and C is the average concentration of the replicate samples. The analyzer precision at each
concentration was reported in terms of the RSD, e.g.,
RSD =
S_
c
xlOO
(5)
5.3 Linearity
Linearity was assessed by linear regression, with the analyte concentration measured by the
reference method as independent variable and the reading from the Orbeco Mini-Analyst Model
942-032 as dependent variable. Linearity is expressed in terms of the slope, intercept, and the
coefficient of determination (r2).
5.4 Method Detection Limit
The MDL(4) for each Orbeco Mini-Analyst Model 942-032 was assessed from the seven replicate
analyses of a fortified sample with a cyanide concentration of approximately five times the
vendor's estimated detection limit (see Table 3-1). The MDL(4) was calculated from the
following equation:
MDL = txS	(6)
where t is the Student's value for a 99% confidence level, and S is the standard deviation of the
replicate samples. The MDL for each Orbeco Mini-Analyst Model 942-032 was reported
separately.
5.5 Inter-Unit Reproducibility
The results obtained from two identical Orbeco Mini-Analyst Model 942-032s were compiled
independently for each Orbeco Mini-Analyst Model 942-032 and compared to assess inter-unit
reproducibility. The results were interpreted using a linear regression of one Orbeco Mini-
Analyst Model 942-032's results plotted against the results produced by the other Orbeco Mini-
Analyst Model 942-032. If the Orbeco Mini-Analyst Model 942-032s function alike, the slope of
such a regression should not differ significantly from unity.
5.6 Lethal or Near-Lethal Dose Response
The Orbeco Mini-Analyst Model 942-03 is not designed to quantitatively measure near-lethal or
lethal concentrations of cyanide in water. Therefore, the operators and Battelle Verification Test
Coordinator made qualitative observations of their operation while analyzing such samples.
20

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Observations of unusual operational characteristics (rate of color change, unusually intense
color, unique digital readout, etc.) were documented and reported.
5.7 Operator Bias
To assess operator bias for each technology, the results obtained from each operator were
compiled independently and subsequently compared. The results were interpreted using a linear
regression of the non-technical operator's results plotted against the results produced by the
technical operator. If the operators obtain identical results, the slope of such a regression should
not differ significantly from unity.
5.8	Field Portability
The results obtained from the measurements made on drinking water samples in the laboratory
and field settings were compiled independently for each Orbeco Mini-Analyst Model 942-032
and for each operator and compared to assess the accuracy of the measurements under the
different analysis conditions. The results were interpreted qualitatively since factors such as
temperature and matrix effects largely influenced the results.
5.9	Ease of Use
Ease of use was a qualitative measure of the user friendliness of the instrument, including how
easy or hard the instruction manual was to use.
5.10 Sample Throughput
Sample throughput indicated the amount of time required to analyze a sample, including both
sample preparation and analysis.
21

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Chapter 6
Test Results
The results of the verification test of the Orbeco Mini-Analyst Model 942-032 are presented in
this section.
6.1 Accuracy
Tables 6-la-d present the measured cyanide results from analysis of the PT samples; surface
water; drinking water from various regions of the United States; and drinking water from
Columbus, OH, respectively, for both the reference analyses and the Orbeco Mini-Analyst
Model 942-032. Results are shown for the technical and non-technical operators and for both
Orbeco Mini-Analyst Model 942-032s that were tested (labeled as Unit #1 and #2). The 0.800-
mg/L PT sample was outside the detectable range of the Orbeco Mini-Analyst Model 942-032.
When these samples were inserted into the Orbeco Mini-Analyst Model 942-032, the result was
reported as "dilute and retest." The only sample that produced the "dilute and retest" result was
the 0.800 mg/L PT sample.
All of the background Alum Creek reservoir surface water samples resulted in responses that
were near or less than the Orbeco Mini-Analyst Model 942-032's detection limit. When
analyzing the background Olentangy River water samples, the technical operator's result on both
Orbeco Mini-Analyst Model 942-032s was "off scale" for seven out of eight replicates (see
Table 6-lb). There was no visible color change in these samples, they were not unusually turbid,
and the result produced by the reference method was <0.005 mg/L. The manufacturer informed
Battelle that this message would be displayed when samples are more colorless than a blank
water sample. The non-technical operator's results were reported as below the detection limit of
the analyzers, which agreed with the reference laboratory results. Both operators were analyzing
surface water aliquots from the same sample and using an identical analysis technique. The "off
scale" result also was obtained when analyzing the lethal/near-lethal concentration samples (see
Section 6.6).
22

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Table 6-la. Cyanide Results from Performance Test Samples
Non-Technical Operator	Technical Operator
Prepared
Concentration
(mg/L)
Ref. Cone.
(mg/L)
Unit #1
(mg/L)
Unit #2
(mg/L)
Unit #1
(mg/L)
Unit #2
(mg/L)
0.030
0.027
0.025
0.023
0.023
0.023
0.030
0.023
0.025
0.024
0.022
0.023
0.030
0.026
0.018
0.019
0.023
0.027
0.030
0.023
0.020
0.021
0.025
0.024
0.100
0.102
0.085
0.086
0.090
0.093
0.100
0.089
0.081
0.085
0.088
0.093
0.100
0.097
0.077
0.079
0.086
0.089
0.100
0.103
0.079
0.083
0.088
0.088
0.200
0.173
0.161
0.168
0.164
0.171
0.200
0.179
0.141
0.144
0.163
0.170
0.200
0.173
0.160
0.162
0.164
0.170
0.200
0.174
0.158
0.164
0.156
0.165
0.400
0.381
0.314
0.323
0.320
0.333
0.400
0.392
0.313
0.318
0.311
0.321
0.400
0.392
0.311
0.320
0.325
0.333
0.400
0.395
0.300
0.311
0.325
0.335
0.800
0.736
DR(a)
DR
DR
DR
0.800
0.724
DR
DR
DR
DR
0.800
0.720
DR
DR
DR
DR
0.800
0.740
DR
DR
DR
DR
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Table 6-lb. Cyanide Results from Surface Water


Non-Technical Operator
Technical Operator
Sample
Description
Ref. Cone.
(mg/L)
Unit #1
(mg/L)
Unit #2
(mg/L)
Unit #1
(mg/L)
Unit #2
(mg/L)
Alum Creek
Background
<0.005
0.005
0.005
<0.002
<0.002
Alum Creek
Background
<0.005
<0.002
<0.002
<0.002
<0.002
Alum Creek
Background
<0.005
<0.002
<0.002
<0.002
<0.002
Alum Creek
Background
<0.005
<0.002
<0.002
<0.002
<0.002
Alum Creek LFM
0.166
0.150
0.155
0.161
0.168
Alum Creek LFM
0.183
0.147
0.153
0.165
0.169
Alum Creek LFM
0.173
0.145
0.151
0.167
0.176
Alum Creek LFM
0.151
0.147
0.154
0.165
0.170
Olentangy River
Background
<0.005
<0.002
0.002
OS(a)
OS
Olentangy River
Background
<0.005
0.004
0.004
OS
OS
Olentangy River
Background
<0.005
0.003
0.004
<0.002
OS
Olentangy River
Background
<0.005
0.003
0.003
OS
OS
Olentangy River
LFM
0.174
0.173
0.182
0.193
0.194
Olentangy River
LFM
0.178
0.165
0.170
0.161
0.163
Olentangy River
LFM
0.171
0.157
0.162
0.167
0.170
Olentangy River
LFM
0.176
0.159
0.165
0.165
0.166
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Table 6-lc. Cyanide Results from U.S. Drinking Water
Non-Technical Operator	Technical Operator
Ref.

Cone.
Unit #1
Unit #2
Unit #1
Unit #2
Sample Description
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
Des Moines, I A,
<0.005
0.002
0.002
OS0"
OS
Background





Des Moines, I A,
NR(a)
NR
NR
OS
OS
Background





Des Moines, I A,
NR
NR
NR
OS
OS
Background





Des Moines, I A,
NR
NR
NR
OS
OS
Background





Des Moines, IA, LFM
0.173
0.147
0.154
0.171
0.164
Des Moines, IA, LFM
0.173
0.153
0.159
0.173
0.168
Des Moines, IA, LFM
0.183
0.092
0.105
0.171
0.165
Des Moines, IA, LFM
0.181
0.138
0.143
0.175
0.169
Flagstaff, AZ,
<0.005
<0.002
<0.002
OS
OS
Background





Flagstaff, AZ,
NR(a)
NR
NR
OS
OS
Background





Flagstaff, AZ,
NR
NR
NR
OS
OS
Background





Flagstaff, AZ,
NR
NR
NR
OS
OS
Background





Flagstaff, AZ, LFM
0.157
0.124
0.129
0.154
0.153
Flagstaff, AZ, LFM
0.132
0.115
0.122
0.148
0.143
Flagstaff, AZ, LFM
SL(c)
0.068
0.079
0.148
0.142
Flagstaff, AZ, LFM
0.169
0.109
0.112
0.150
0.145
(a)	NR = sample not analyzed because initial aliquot analyzed by the non-technical operator resulted in a cyanide
concentration below 0.002 mg/L. The technical operator analyzed four background samples because of the "off
scale" result from the initial aliquot.
(b)	OS = Orbeco Mini-Analyst Model 942-032 reported "off scale" on the digital display. According to the manu
facturer, this indicates a color outside (under or over) the detectable range of the colorimeter. In the case of these
samples, there was no color change indicating a below-detectable result.
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Table 6-lc. Cyanide Results from U.S. Drinking Water (continued)


Non-Technical Operator
Technical Operator
Sample
Description
Ref.
Cone.
(mg/L)
Unit #1
(mg/L)
Unit #2
(mg/L)
Unit #1
(mg/L)
Unit #2
(mg/L)
Montpelier, VT,
Background
<0.005
<0.002
0.003
<0.002
<0.002
Montpelier, VT,
LFM
0.167
0.152
0.156
0.155
0.161
Montpelier, VT,
LFM
0.176
0.145
0.150
0.155
0.162
Montpelier, VT,
LFM
0.168
0.149
0.154
0.160
0.165
Montpelier, VT,
LFM
0.168
0.149
0.153
0.157
0.161
Seattle, WA,
Background
<0.005
<0.002
<0.002
<0.002
<0.002
Seattle, WA, LFM
0.177
0.129
0.133
0.161
0.169
Seattle, WA, LFM
0.174
0.167
0.172
0.164
0.171
Seattle, WA, LFM
0.170
0.156
0.161
0.163
0.168
Seattle, WA, LFM
0.172
0.150
0.155
0.158
0.164
Tallahassee, FL,
Background
<0.005
<0.002
<0.002
OS
OS
Tallahassee, FL,
Background
NR
NR
NR
OS
OS
Tallahassee, FL,
Background
NR
NR
NR
OS
OS
Tallahassee, FL,
Background
NR
NR
NR
OS
OS
Tallahassee, FL,
LFM
0.157
<0.002
<0.002
0.091
0.089
Tallahassee, FL,
LFM
0.161
<0.002
<0.002
0.086
0.084
Tallahassee, FL,
LFM
0.165
<0.002
<0.002
0.069
0.069
Tallahassee, FL,
LFM
0.159
<0.002
<0.002
0.050
0.048
26
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Table 6-Id. Cyanide Results from Columbus, OH, Drinking Water
Non-Technical Operator	Technical Operator
Sample Description
Ref.
Cone.
(mg/L)
Unit #1
(mg/L)
Unit #2
(mg/L)
Unit #1
(mg/L)
Unit #2
(mg/L)
City Water Background -
Outdoor Field Site
<0.005
<0.002
<0.002
<0.002(a)
<0.002(b)
City Water Background -
Indoor Field Site
<0.005
<0.002
<0.002
<0.002
<0.002
City Water Background -
Lab
<0.005
<0.002
<0.002
OS®
<0.002
City Water Background -
Lab
<0.005
<0.002
<0.002
OS
<0.002
City Water Background -
Lab
<0.005
0.002
<0.002
<0.002
<0.002
City Water Background -
Lab
<0.005
<0.002
<0.002
OS
<0.002
City Water LFM - Outdoor
Field Site
0.176
0.060
0.063
0.058(a)
0.054(a)
City Water LFM - Outdoor
Field Site
0.167
0.066
0.067
0.067(a)
0.062(a)
City Water LFM - Outdoor
Field Site
0.165
0.066
0.066
0.059(a)
0.06 l(a)
City Water LFM - Outdoor
Field Site
0.178
0.054
0.058
0.053(a)
0.055(a)
City Water LFM - Indoor
Field Site
0.176
0.107
0.112
0.109
0.115
City Water LFM - Indoor
Field Site
0.167
0.117
0.122
0.105
0.109
City Water LFM - Indoor
Field Site
0.165
0.115
0.120
0.106
0.112
City Water LFM - Indoor
Field Site
0.178
0.108
0.113
0.112
0.116
City Water LFM - Lab
0.176
0.072
0.079
0.072
0.077
City Water LFM - Lab
0.167
0.071
0.074
0.076
0.081
City Water LFM - Lab
0.165
0.078
0.081
0.073
0.076
City Water LFM - Lab
0.178
0.076
0.077
0.067
0.071
27
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Table 6-ld. Cyanide Results from Columbus, OH, Drinking Water (continued)


Non-Technical Operator
Technical Operator
Sample Description
Ref.
Cone.
(mg/L)
Unit #1
(mg/L)
Unit #2
(mg/L)
Unit #1
(mg/L)
Unit #2
(mg/L)
Well Water Background -
Outdoor Field Site
<0.005
<0.002
<0.002
0.014
0.015
Well Water Background -
Indoor Field Site
<0.005
<0.002
<0.002
<0.002
<0.002
Well Water Background -
Lab
<0.005
0.002
<0.002
OS
<0.002
Well Water Background -
Lab
<0.005
<0.002
<0.002
OS
<0.002
Well Water Background -
Lab
<0.005
0.002
<0.002
OS
<0.002
Well Water Background -
Lab
<0.005
0.003
<0.002
<0.002
<0.002
Well Water LFM - Outdoor
Field Site
0.100
0.069
0.071
0.044
0.050
Well Water LFM - Outdoor
Field Site
0.121
0.066
0.070
0.053
0.056
Well Water LFM - Outdoor
Field Site
0.114
0.055
0.058
0.044
0.050
Well Water LFM - Outdoor
Field Site
0.091
0.064
0.067
0.045
0.064
Well Water LFM - Indoor
Field Site
0.100
0.147
0.153
0.135
0.141
Well Water LFM - Indoor
Field Site
0.121
0.149
0.155
0.131
0.138
Well Water LFM - Indoor
Field Site
0.114
0.144
0.149
0.132
0.137
Well Water LFM - Indoor
Field Site
0.091
0.140
0.145
0.138
0.145
Well Water LFM - Lab
0.100
0.073
0.076
0.013
0.015
Well Water LFM - Lab
0.121
0.013
0.014
0.013
0.015
Well Water LFM - Lab
0.114
0.010
0.012
0.015
0.015
Well Water LFM - Lab
0.091
0.009
0.009
0.011
0.014
(a)	Sample analyzed at a pH between 10.5 and 11.0.
(b)	OS = Orbeco Mini-Analyst Model 942-032 reported "off scale" on the digital display. According to the manu
facturer, this indicates a color outside (under or over) the detectable range of the colorimeter. In the case of these
samples, there was no color change indicating a below-detectable result.
28
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Similar results were obtained when analyzing the drinking water samples from around the
United States and from Columbus, OH. The background samples from Des Moines, Flagstaff,
and Tallahassee produced "off scale" results for both analyzers when operated by the technical
operator (see Table 6-lc). The non-technical operator's results were consistently below or near
the detection limit of the analyzers. When analyzing the background Columbus, OH, area
drinking water samples in the laboratory, the technical operator produced "off scale" results
only on Unit #1 (see Table 6-Id). The technical operator's results on Unit #2 and the non-
technical operator's results on both technologies were consistently below or near the detection
limit of the analyzers. Both operators were analyzing drinking water aliquots from the same
sample and using an identical analysis technique. There was no visible color change in these
samples, and they were not unusually turbid. As reported by the manufacturer, the "off scale"
result is displayed when samples are more colorless than a blank water sample.
Tables 6-2a-d present the percent accuracy of the Orbeco Mini-Analyst Model 942-032 results.
The bias values were determined according to Equation (3), Section 5.1. Bias was not
calculated for background samples with non-detectable concentrations of cyanide. In instances
when the LFM samples had a detectable concentration in the reference analysis, but a non-
detect reading from the Orbeco Mini-Analyst 942-032, the bias was reported as 100%. The bias
values shown in Tables 6-2a-d can be summarized by the range of bias observed with different
sample sets. For example, the biases ranged from 3 to 21% for the PT samples; 5 to 12% for the
surface water samples; 3 to 100% for the drinking water samples from around the country; and
25 to 94% for the Columbus, OH, drinking water samples. Because of the low well water
reference LFM sample recovery (see Section 4.1 and Table 4-2), the well water biases were
calculated using the fortified concentration of 0.200 mg/L as the reference concentration.
Table 6-2a. Percent Accuracy of Performance Test Sample Measurements
Non-Technical Operator	Technical Operator
Sample
Concentration
(mg/L)
Unit #1
(bias)
Unit #2
(bias)
Unit #1
(bias)
Unit #2
(bias)
0.030
15%
14%
10%
6%
0.100
18%
15%
10%
9%
0.200
11%
9%
7%
3%
0.400
21%
18%
18%
15%
0.800
NA(a)
NA
NA
NA
(a) NA = calculation of bias not appropriate when result was outside the detectable range of the Orbeco Mini-Analyst
Model 942-032.
29
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Table 6-2b. Percent Accuracy of Surface Water Measurements

Non-Technical Operator
Technical Operator
Sample Description
Unit #1 (bias)
Unit #2 (bias)
Unit #1 (bias)
Unit #2 (bias)
Alum Creek LFM
12%
10%
6%
6%
Olentangy River LFM
6%
5%
7%
7%
Table 6-2c. Percent Accuracy of U.S. Drinking Water Tests

Non-Technical Operator
Technical Operator
Sample Description
Unit #1 (bias)
Unit #2 (bias)
Unit #1 (bias)
Unit #2 (bias)
Des Moines, IA, LFM
25%
21%
3%
6%
Flagstaff, AZ, LFM
32%
28%
7%
8%
Montpelier, VT, LFM
12%
10%
8%
4%
Seattle, WA, LFM
13%
10%
7%
3%
Tallahassee, FL, LFM
100%(a)
100%(a)
54%
55%
(a)100% bias due to non-detect reading from the Orbeco Mini-Analyst Model 942-032.

Table 6-2d. Percent Accuracy of Columbus, OH, Drinking Water Measurements

Non-Technical Operator
Technical Operator
Sample Description
Unit #1 (bias)
Unit #2 (bias)
Unit #1 (bias)
Unit #2 (bias)
City Water LFM - Outdoor
64%
63%
65%(b)
66%(b)
Field Site




City Water LFM - Indoor
35%
32%
37%
34%
Field Site




City Water LFM - Lab
57%
55%
58%
56%
Well Water LFM -
68%
67%
77%
73%
Outdoor Field Site




Well Water LFM - Indoor
28%
25%
33%
30%
Field Site




Well Water LFM - Lab(a)
87%
86%
94%
93%
(a) Due to an approximately 50% reference LFM recovery in the well water sample (see Table 4-2), these biases
were calculated using the fortified concentration of 0.200 mg/L as the reference concentration.
-------
6.2 Precision
Tables 6-3a-d show the RSDs of the cyanide analysis results for PT samples; surface water;
drinking water from around the U.S.; and drinking water from Columbus, OH, from the Orbeco
Mini-Analyst Model 942-032 and the reference method. Results are shown for the technical
and non-technical operators and for both units that were tested. RSDs were not calculated for
results reported as less than the MDL of the Orbeco Mini-Analyst Model 942-032 or those
samples that produced "dilute and retest" or "off scale" results. The RSD values shown in
Tables 6-3a-d can be summarized by the range of RSDs observed with different sample sets.
For example, the RSDs ranged from 2 to 16% for the PT samples; 1 to 8% for the surface water
samples; 1 to 25% for the drinking water samples from around the country; and 2 to 13% for
the Columbus, OH, area drinking water samples (except for the non-technical operator's results
for the well water analyzed in the laboratory, which had RSDs of over 100%).
Table 6-3a. Relative Standard Deviation of Performance Test Sample Measurements

Non-Technical Operator
Technical Operator
Reference




Concentration Method
Unit #1
Unit #2
Unit #1
Unit #2
(mg/L) (RSD)
(RSD)
(RSD)
(RSD)
(RSD)
0.030 8%
16%
10%
5%
8%
0.100 7%
4%
4%
2%
3%
0.200 2%
6%
7%
2%
2%
0.400 2%
2%
2%
2%
2%
0.800 1%
NA(a)
NA
NA
NA
(a) NA = calculation of precision not appropriate when sample produced a'
''dilute and retest" result.

Table 6-3b. Relative Standard Deviation of Surface Water Measurements


Non-Technical Operator
Technical Operator
Reference




Method
Unit #1
Unit #2
Unit #1
Unit #2
Sample Description (RSD)
(RSD)
(RSD)
(RSD)
(RSD)
Alum Creek LFM 8%
1%
1%
2%
2%
Olentangy River LFM 2%
4%
5%
8%
8%
31
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Table 6-3c. Relative Standard Deviation of U.S. Drinking Water Measurements


Non-Technical Operator
Technical Operator
Sample Description
Reference
Method
(RSD)
Unit #1
(RSD)
Unit #2
(RSD)
Unit #1
(RSD)
Unit #2
(RSD)
Des Moines, IA, LFM
3%
21%
17%
1%
1%
Flagstaff, AZ, LFM
12%
24%
20%
2%
3%
Montpelier, VT, LFM
2%
2%
2%
2%
1%
Seattle, WA, LFM
2%
11%
11%
2%
2%
Tallahassee, FL, LFM
2%
NA(a)
NA
25%
25%
(a) NA = calculation of precision not appropriate when result was below the detection limit of the Orbeco Mini-
Analyst Model 942-032.
Table 6-3d. Relative Standard Deviation of Columbus, OH, Drinking Water
Measurements



Non-Technical Operator
Technical Operator
Sample Description
Reference
Method
(RSD)
Unit #1
(RSD)
Unit #2
(RSD)
Unit #1
(RSD)
Unit #2
(RSD)
City Water LFM -
Outdoor Field Site
4%
9%
6%
10%(a)
7 %(a)
City Water LFM -
Indoor Field Site
4%
4%
4%
3%
3%
City Water LFM - Lab
4%
4%
4%
5%
5%
Well Water LFM -
Outdoor Field Site
13%
9%
9%
9%
12%
Well Water LFM -
Indoor Field Site
13%
3%
3%
2%
3%
Well Water LFM - Lab
13%
119%
116%
13%
3%
(a) Samples analyzed at pH 10.5 to 11.0.
6.3 Linearity
The linearity of the Orbeco Mini-Analyst Model 942-032 was assessed by using a linear
regression of the PT results against the reference method results (Table 6-la). Figures 6-1 and
6-2 show scatter plots of the results from the non-technical and technical operator, respectively,
versus the reference results. A dotted regression line with a slope of unity and intercept of zero
also is shown in Figures 6-1 and 6-2.
32
-------
y = 0.7968X + 0.0068
r2 = 0.9913
0.25 -
0.15 -
0.05 -
0.1 0.15 0.2 0.25 0.3 0.35
Reference Method Results (mg/L)
0.45
Figure 6-1. Non-Technical Operator Linearity Results
0.45
0.4
y = 0.8204X + 0.01
I2 = 0.9932
0.35
0.3
0.25
0.2
0.15
.1
0.05
0
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
Reference Method Results (mg/L)
Figure 6-2. Technical Operator Linearity Results
A linear regression of the data in Figure 6-1 for the non-technical operator gives the following
regression equation:
y (non-technical operator results in mg/L)=0.797 (± 0.028) x (reference result in
mg/L)
+ 0.007 (± 0.006) mg/L with r=0.991 and N=32.
A lineal- regression of the data in Figure 6-2 for the technical operator gives the following
regression equation:
y (technical operator results in mg/L)=0.820 (± 0.025) x (reference result in mg/L)
+ 0.010 (± 0.006) mg/L with r=0.993 and N=32.
where the values in parentheses represent the 95% confidence interval of the slope and
intercept. Only the technical operator's intercept is significantly different from zero, and the r
33
-------
values are both above 0.99. Both slopes are significantly different from unity at the 95%
confidence interval, but the slopes are not significantly different from another.
6.4 Method Detection Limit
The manufacturer's estimated detection limit for the Orbeco Mini-Analyst Model 942-032 is
0.002 mg/L cyanide. The MDL(4) was determined by analyzing seven replicate samples at a
concentration of 0.010 mg/L. Table 6-4 shows the results of the MDL assessment. The MDL
determined as described in Equation (6) of Section 5.4 was 0.004 mg/L for the Orbeco Mini-
Analyst Model 942-032 when used by the non-technical operator and 0.005 mg/L when used by
the technical operator.
Table 6-4. Results of Method Detection Limit Assessment
Non-Technical Operator	Technical Operator
MDL Cone.
Unit #1
Unit #2
Unit #1
Unit #2
(mg/L)
(mg/L)
(mg/L)
(mg/L)
(mg/L)
0.010
0.004
0.005
0.006
0.006
0.010
0.004
0.005
0.007
0.007
0.010
0.003
0.002
0.006
0.008
0.010
0.005
0.005
0.006
0.008
0.010
0.006
0.006
0.001
0.001
0.010
0.005
0.005
0.006
0.007
0.010
0.006
0.005
0.009
0.001
Std Dev
0.0011
0.0012
0.0017
0.0015
t(n=7)
0.0031
0.0031
0.0031
0.0031
MDL (mg/L)
0.004
0.004
0.005
0.005
6.5 Inter-Unit Reproducibility
The inter-unit reproducibility of the Orbeco Mini-Analyst Model 942-032 was assessed by
using a linear regression of the results produced by one Orbeco Mini-Analyst Model 942-032
plotted against the results produced by the other Orbeco Mini-Analyst Model 942-032. The
results from all of the samples that had detectable amounts of cyanide (including the PT,
surface, and drinking water samples) produced by both operators were included in this
regression. Figure 6-3 shows a scatter plot of the results from both Orbeco Mini-Analyst Model
942-032s.
34
-------
0.35
y = 0.9764X - 0.0009
r2 = 0.9975
* 0.15 -
= 0.1 -
0.05 -
0 -
0	0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4
Unit #2 (mg/L)
Figure 6-3. Inter-Unit Reproducibility Results
A linear regression of the data in Figure 6-3 for the inter-unit reproducibility assessment gives
the following regression equation:
y (Unit #1 result in mg/L)=0.976 (± 0.008) x (Unit #2 result in mg/L)
- 0.0009 (± 0.0012) mg/L with r=0.998 and N=136.
where the values in parentheses represent the 95% confidence interval of the slope and
intercept. The slope is just slightly less than unity and the intercept is not significantly different
from zero. These data indicate that the two Orbeco Mini-Analyst Model 942-032s functioned
veiy similarly to one another.
6.6 Lethal or Near-Lethal Dose Response
Samples at 50.0-, 100-, and 250-mg/L concentrations (close to what may be lethal if a volume
the size of a typical glass of water was ingested) were prepared and analyzed by the Orbeco
Mini-Analyst Model 942-032. Upon adding the reagents to the water sample, the color of the
sample changed within five seconds to bright red and then progressed to a dark blue after about
five minutes. The change was much more rapid than for any of the PT samples. The PT samples
took about 30 seconds to produce a small change in the color of the sample and took the full
15-minute reaction time to reach its analysis color of a clear, light blue. When these samples
with lethal/near-lethal concentrations were inserted into the Orbeco Mini-Analyst Model 942-
032 after the full reaction time, the digital readout read "off scale." According to the manu-
facturer's instruction manual, the result should have been "dilute and retest" when analyzing a
sample with a cyanide concentration higher than the detectable range of the Orbeco Mini-
Analyst Model 942-032.
35
-------
6.7 Operator Bias
The possible difference in results produced by the non-technical and technical operators was
assessed by using a linear regression of the results produced by the non-technical operator
plotted against the results produced by the technical operator. The results from all of the
samples that had detectable amounts of cyanide (including the PT, surface, and drinking water
samples) from both units were included in this regression. Figure 6-4 shows a scatter plot of the
results from both units.
0.35
0.3
j 0.25 -
D>
£ 0.2 -
o
g 0.15 -
a>
Q.
o 0.1 -
0.05 -
0
y = 0.9331x-0.0018

.vj
r2 = 0.8902


•V
>T*#
•
•
¦

0.05 0.1 0.15 0.2 0.25
Technical Operator (mg/L)
0.3
0.35
0.4
Figure 6-4. Non-Technical vs. Technical Operator Bias
Results
A lineal- regression of the data in Figure 6-4 for the operator bias assessment gives the
following regression equation:
y (non-tech result in mg/L)=0.933 (± 0.056) x (tech result in mg/L)
- 0.002 (± 0.008) mg/L with r=0.890 and N=136.
where the values in parentheses represent the 95% confidence interval of the slope and
intercept. The slope of this regression is less than 10% different from unity indicating a slight
difference in the results produced by the operators. The relatively low coefficient of variation is
mostly due to the samples from Flagstaff, AZ. The technical operator generated detectable
responses for all of the Flagstaff, AZ, samples, while the non-technical operator did not. The
reason for this discrepancy is not explainable, but it did not occur for any other water sample. If
these eight data points are removed from the regression, the r value increases to approximately
0.94 while the slope remains approximately 0.9. In the two plots describing linearity in
Section 6.3, the slopes for each operator are not significantly different from one another. If one
operator was significantly different from the other, the slope intervals produced by the 95%
confidence intervals of the linearity plots would not overlap.
36
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6.8 Field Portability
The Orbeco Mini-Analyst Model 942-032 was operated in laboratory and field settings during
this verification test. Tables 6-Id, 6-2d, and 6-3d show the results of these measurements. From
an operational standpoint, the Orbeco Mini-Analyst Model 942-032 was easily transported to
the field setting, and the samples were analyzed in the same fashion as they were in the labora-
tory. No functional aspects of the Orbeco Mini-Analyst Model 942-032 were compromised by
performing the analyses in the field setting. However, performing analyses under extremely
cold conditions (sample water temperatures between 4 and 6°C) negatively affected the
performance of the Orbeco Mini-Analyst Model 942-032 reagents. The low temperatures
apparently slowed the chemical reaction rates, which caused the decreased color change in the
LFM samples.
Table 6-2d shows the bias of the samples analyzed in the field setting (indoors with sample
temperatures of approximately 16°C and outdoors with sample temperatures of 4 to 6°C) and of
the identical samples analyzed at the laboratory at approximately 20°C. The well and
Columbus, OH, city water samples were both dechlorinated as described in Section 3.5.1. In
addition, because the well water sample had a pungent odor, lead carbonate was added after
NaOH preservation to check for the presence of sulfides. The lead carbonate did not turn black.
Such a color change would have indicated the presence of sulfides. Nonetheless, there was a 32
to 37% bias in the indoor Columbus, OH, city water measurements and a 25 to 33% bias in the
indoor well water measurements. Because there was an apparent matrix interference in the
reference measurement (see Table 4-2), the well water biases were calculated using the fortified
concentration (0.200 mg/L) as the reference concentration.
The apparent matrix interference in the well water LFM seemed to progressively mask the
cyanide in the LFM sample after it was spiked and analyzed at the indoor field setting
(producing a 25 to 33% bias from initial fortification) because, by the time the well water LFM
samples were analyzed by the Orbeco Mini-Analyst Model 942-032 at the laboratory two days
after initial fortification, there was very little detectable cyanide (86 to 94% bias from initial
fortification). These same samples were analyzed using the reference method eight days after
initial fortification, and the result was below the MDL of the reference method (Table 4-2).
The concentration of cyanide in that same LFM aliquot was determined to be below detectable
levels by the reference method (Table 4-2). Because there was an apparent time-dependent
matrix interference, the data generated from the well water samples using the Orbeco Mini-
Analyst Model 942-032 in the field setting cannot be meaningfully compared with the result
produced from the identical samples analyzed with the Orbeco Mini-Analyst Model 942-032 in
the laboratory.
The bias in the Columbus, OH, city water indoor LFM sample (32 to 37%) was considerably
less than the bias in the Columbus, OH, city water LFM sample analyzed at the laboratory
location (55 to 58%), as shown in Table 6-2d. The apparent matrix interference seemed to mask
the cyanide in the LFM sample, as evidenced by the increasing biases from the time the
samples were analyzed at the field location to when they were analyzed at the laboratory two
days later. Therefore, no meaningful comparison between samples measured at the field
location and at the laboratory can be made.
37
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6.9 Ease of Use
The pH of the samples analyzed by the Orbeco Mini-Analyst Model 942-032 had to be adjusted
to between 6.0 and 7.0. From a safety standpoint, that is not desirable because HCN can be
released at a pH below 9.0. Also, the odor of the solution of pyridine used as a reagent was
quite offensive. Both operators preferred to use the Orbeco Mini-Analyst Model 942-032 in a
laboratory hood so they would not have to be concerned about the evolution of HCN gas and
the smell of the pyridine.
The instructions for pH adjustment were clear. If the samples were preserved at exactly 0.020
M NaOH, then 1.00 mL each of the Orbeco Buffer and 1.75 M HC1 provided by Orbeco
adjusted the pH very close to the 6.0 to 7.0 range. A slight additional adjustment was necessary.
A 10.0-mL aliquot sample of the pH-adjusted sample was then measured into a mixing vial
with a graduated cylinder, and reagents were added one at a time with a prescribed mixing
reaction time after each reagent. The operators thought that it was inconvenient to keep track of
the mixing and waiting time periods during the analysis. Also, the granular reagents came in
plastic capsules that were difficult to open. When the reagent addition and 15-minute color
development period was complete, the samples were inserted into the Orbeco Mini-Analyst
Model 942-032, and the cyanide concentration was read in micrograms per liter.
6.10 Sample Throughput
Sample preparation, including accurate volume measurement and the addition of reagents, took
only two to three minutes per sample. After performing the sample preparation, a 15-minute
period of color development is required before sample analysis. Therefore, if only one sample is
analyzed, it would take approximately 18 minutes. However, both operators were able to
stagger the start of the color development period every two minutes for subsequent samples, so
a typical sample set of 12 analyses took 45 to 50 minutes. Since the color development reaction
takes place in reusable reaction vials, additional vials would have to be purchased to
conveniently analyze large sample sets.
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Chapter 7
Performance Summary
The biases ranged from 3 to 21% for the PT samples; 5 to 12% for the surface water samples,
3 to 100% for the drinking water samples from around the country; and 25 to 94% for the
Columbus, OH, drinking water samples. All the results were biased low compared with the
reference result. In several instances when analyzing background surface and drinking water
samples, the Orbeco Mini-Analyst Model 942-032 produced "off scale" results when being
operated by the technical operator. There was no color change in these samples, and they were
not unusually turbid. When the same samples were analyzed individually by the non-technical
operator, the result was below the detection limit of the Orbeco Mini-Analyst Model 942-032.
Also, the reference LFM sample of the Columbus, OH, well water sample resulted in poor
recovery in fortified cyanide. For this reason, the bias calculations for the well water samples
were done using the fortified concentration of cyanide.
The RSDs ranged from 2 to 16% for the PT samples; 1 to 8% for the surface water samples; 1
to 25% for the drinking water samples from around the country; and 2 to 13% for the
Columbus, OH, drinking water samples (except for the non-technical operator's results for the
well water analyzed in the laboratory, which had RSDs over 100%).
A linear regression of the linearity data for the non-technical operator gives the following
regression equation:
y (non-technical operator results in mg/L)=0.797 (± 0.028) x (reference result in
mg/L)
+ 0.007 (± 0.006) mg/L with r2=0.991 and N=32.
A linear regression of the data for the technical operator gives the following regression
equation:
y (technical operator results in mg/L)=0.820 (± 0.025) x (reference result in mg/L)
+ 0.010 (± 0.006) mg/L with r2=0.993 and N=32.
where the values in parentheses represent the 95% confidence interval of the slope and
intercept. Only the technical operator's intercept is significantly different from zero, and the r2
values are both above 0.990. The linearity of the Orbeco Mini-Analyst Model 942-032 was not
dependent on which operator was performing the analyses. The slope of the linear regression
was significantly less than unity in both instances. This deviation from unity indicates a low
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bias in the results generated by the Orbeco Mini-Analyst Model 942-032 compared with the
results produced by the reference method.
The MDL was determined to be 0.004 mg/L for the Orbeco Mini-Analyst Model 942-032 when
used by the non-technical operator and 0.005 mg/L when used by the technical operator.
A linear regression of the data for inter-unit reproducibility gives the following regression
equation:
y (Unit #1 result in mg/L)=0.976 (± 0.008) x (Unit #2 result in mg/L)
-	0.0009 (± 0.0012) mg/L with r2=0.998 and N=136.
where the values in parentheses represent the 95% confidence interval of the slope and
intercept. The slope is just slightly less than unity, and the intercept is not significantly different
from zero. These data indicate that the two Orbeco Mini-Analyst Model 942-032s functioned
very similarly to one another.
When analyzing samples containing lethal/near-lethal concentrations of cyanide, the difference
in color development was remarkable. Upon adding the reagents to the water sample, the color
of the sample changed within five seconds to bright red and then progressed to a dark blue
throughout the next five minutes. The change was much more rapid than for any of the PT
samples. The PT samples took about 30 seconds to produce a small change in the color of the
sample and took the full 15-minute reaction time to reach its analysis color of a clear, light
blue. When the samples with lethal/near-lethal concentrations were inserted into the Orbeco
Mini-Analyst Model 942-032 after the full reaction time, the digital readout read "off scale."
Even without using the Orbeco Mini-Analyst Model 942-032, the reagent and glass vials would
be useful for a first responder seeking to find out whether a toxic level of cyanide is present in a
drinking water sample. The presence of such concentrations could be confirmed within minutes
by visual observation of the color development process.
A linear regression of the data for the operator bias assessment gives the following regression
equation:
y (non-tech result in mg/L)=0.933 (± 0.056) x (tech result in mg/L)
-	0.002 (± 0.008) mg/L with r2=0.890 and N=136.
where the values in parentheses represent the 95% confidence interval of the slope and
intercept. The slope of this regression is less than 10% different from unity, indicating a slight
difference in the results produced by the operators. The relatively low coefficient of variation
was mostly due to the Flagstaff, AZ, samples. The technical operator generated detectable
results, while the non-technical operator did not. These data, in combination with the operator-
specific linearity data from Section 6.3, indicate that, in general, the functioning of the Orbeco
Mini-Analyst Model 942-032 is not dependent on which operator is performing the analyses.
From an operational standpoint, the Orbeco Mini-Analyst Model 942-032 was easily
transported to the field setting, and the samples were analyzed in the same fashion as they were
in the laboratory. No functional aspects of the Orbeco Mini-Analyst Model 942-032 were com-
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promised by performing the analyses in the field setting. However, performing analyses under
extremely cold conditions negatively affected the performance of the Orbeco Mini-Analyst
Model 942-032. The low temperatures apparently slowed the chemical reaction rates, which
caused the decreased color change in the LFM samples.
The manufacturer recommends adjusting the pH of water samples to be analyzed by the Orbeco
Mini-Analyst Model 942-032 to between 6.0 and 7.0. Since gaseous HCN can be released at a
pH less than 9.0, this adjustment is not desirable from a safety standpoint, especially if
lethal/near-lethal concentrations of cyanide are present. The sample preparation instructions
were clear, but the liquid pyridine reagent had an offensive odor, and the granular reagent
tablets were difficult to open. Also, the operators thought that it was inconvenient to keep track
of the mixing and waiting times during the analysis.
Sample preparation, including measuring volumes and using reagents, took two to three
minutes per sample. After performing the sample preparation, a 15-minute period of color
development was required before sample analysis. Therefore, if only one sample is analyzed, it
would take approximately 18 minutes. However, both operators were able to stagger the start of
the color development period every two minutes for subsequent samples, so a typical sample set
of 12 analyses took 45 to 50 minutes. Since the color development reaction takes place in
reusable reaction vials, additional vials would have to be purchased to conveniently analyze
large sample sets.
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Chapter 8
References
1.	Test/QA Plan for Verification of Portable Analyzers for Detection of Cyanide in
Water, Battelle, Columbus, Ohio, January 2003.
2.	U.S. EPA Method 335.1, Cyanides Amenable to Chlorination, 1974, in "Methods for
Chemical Analysis of Water and Wastes," EPA/600/4-79/020, March 1983.
3.	United States Environmental Protection Agency, National Primary Drinking Water
Standards, EPA/816-F-02-013, July 2002.
4.	Code of Federal Regulations, Title 40, Part 136, Appendix B, Definition and
Procedure for the Determination of the Method Detection Limit-Revision 1.11.
5.	Quality Management Plan (QMP)for the ETV Advanced Monitoring Systems Center,
Version 4.0, U.S. EPA Environmental Technology Verification Program, Battelle,
Columbus, Ohio, December 2002.
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