United States
                    Environmental Protection
                    Agency
Environmental Monitoring and
Support Laboratory
Cincinnati OH 45268
                    Research and Development
EPA/600/S4-85/070  Jan. 1986
SER&          Project  Summary
                    EPA Method  Study 31:  Trace
                    Metals  by Atomic  Absorption
                    (Furnace Techniques)
                    T. R. Copeland and J. P. Maney
                     An interlaboratory study in which 10
                   laboratories participated was conduct-
                   ed to provide precision and accuracy
                   statements for the analysis of 18 metals
                   by graphite furnace atomic absorption
                   spectrometry. Samples were prepared
                   and analyzed using procedures speci-
                   fied in "Methods for Chemical Analysis
                   of Water and Wastes." EPA 600/4-
                   797 020, U.S. Environmental  Protec-
                   tion Agency, Environmental Monitoring
                   and Support Laboratory,  Cincinnati,
                   OH, March 1979.
                     The study design was based on You-
                   den's non-replicate design for collabo-
                   rative tests of analytical methods. Three
                   Youden pair samples of the test metals
                   were spiked into six types of test waters
                   and then analyzed. The test waters were
                   three  industrial effluents supplied by
                   ERCO and three waters supplied by the
                   subcontractor laboratories  (laboratory
                   pure water, finished drinking water, and
                   surface water). The resulting data were
                   statistically analyzed  using the com-
                   puter program entitled "Interlaboratory
                   Method Validation Study" (IMVS).
                     The statistical analyses included re-
                   jection of outliers, estimation of mean
                   recovery (accuracy), estimation of single-
                   analyst and overall precisions, and tests
                   for the effects of water type on accuracy
                   and precision.
                     This Project Summary was developed
                   by EPA's Environmental Monitoring and
                   Support Laboratory, Cincinnati. OH. to
                   announce key findings of the research
                   project that is fully documented in a
                   separate report of the same title (see
                   Project Report ordering information at
                   back).
Introduction
  The Safe Drinking Water Act (SDWA)
and the National Pollutant Discharge
Elimination System (NPDES) require that
waters and waste be analyzed to deter-
mine their chemical content. The EPA
was given a mandate to prepare methods
which would be approved for the analysis
of parameters of concern listed by these
laws and resulting regulations.
  The EPA staff of the Environmental
Monitoring and Support Laboratory  of
Cincinnati, Ohio, provided the procedures
for  monitoring metal parameters  in
wastes  and  waters in  the document
entitled, "Methods for Chemical Analysis
of Water and Wastes." The second edi-
tion of this manual, which was published
in March 1979, added atomic absorption
furnace  methods  to  quantitate lower
levels of metal parameters than those
determinable by the flame atomic absorp-
tion methods specified in the first edition.
  Energy Resources Co. Inc. (ERCO) was
contracted by EPA to conduct a method
study to define the accuracy and precision
of the atomic absorption furnace proce-
dure for the following 18 trace metals:
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cobalt
Copper
Iron
Lead
(Method
(Method
(Method
(Method
(Method
(Method
(Method
(Method
(Method
(Method
(Method
202.2)
204.2)
206.2)
208.2)
210.2)
213.2)
218.2)
219.2)
220.2)
236.2)
239.2)

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Manganese
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
(Method
(Method
(Method
(Method
(Method
(Method
(Method
243.2)
249.2)
270.2)
272.2)
279.2)
286.2)
289.2)
  Ten laboratories were selected by ERCO
for participating in the  method study
following  their successful analysis  of
performance evaluation samples. These
laboratories then collected drinking, sur-
face, and  laboratory pure waters while
ERCO supplied them with three different
types of industrial effluents. These waters
and effluents were analyzed to determine
background levels of the elements  of
interest and subsequently specified vol-
umes of unknown  metal concentrates
were added and the samples reanalyzed.
The  added level of  each metal  was
determined by difference.
  Youden's non-replicate collaborative
test design was applied to 10 participating
laboratories.  Formal  statistical tech-
niques compatible with the Youden de-
sign were  used to identify outliers, est-
imate the method's accuracy and preci-
sion, and test for the effect of water type.
The  formal statistical analyses were
carried out using U.S. EPA's IMVS com-
puter program.


Procedure
  The study  consisted of two  distinct
analysis phases. Phase  I involved the
selection of participating laboratories. An
EPA-supplied  list  of  laboratories  and
previous ERCO experience were used to
solicit interested laboratories. Based on
prior experience of the  laboratories  in
graphite furnace analysis; assurance  of
adequate facilities, instrumentation, and
personnel to complete the analyses in a
timely manner; and cost estimates, 12
laboratories were selected to receive two
pre-award performance evaluation sam-
ples. These samples contained acid solu-
tions of eight of the 18 metals of interest
in sealed glass ampules.
  These solutions were spiked into lab-
oratory pure water supplied by the  indi-
vidual participating  laboratories and an-
alyzed by the graphite furnace atomic
absorption procedures to be employed in
the interlaboratory study. The analytical
results  were  submitted to ERCO  for
evaluation.
  Based upon the individual laboratories'
analytical  results and the above criteria,
10 laboratories were selected for partic-
ipation in the study.
  Phase II consisted of the actual inter-
laboratory study. This study required the
analysis of six different water matrices,
spiked at six different concentrations
(three Youden pairs) of all 18 analytes of
interest.  In addition, each participating
laboratory performed an analysis of the
six  waters with no spiked compounds
added. Each participating laboratory then
issued a report of all results to ERCO.
  The  final step in the study was the
statistical analysis of all data by Battelle
Memorial Laboratories using EPA's INVS
system.

Results and Discussion
  The object  of this study was to char-
acterize  the  performance of  graphite
furnace atomic absorption procedures in
terms  of accuracy,  overall  precision,
single-analyst precision, and the effect of
water types on accuracy and precision.
Through the statistical analysis of 8,640
analytical values,  estimates of accuracy
and precision were made and expressed
as regression equations, which are pre-
sented in Table 1.
  Of all  8,640 analytical  values, 23%
were rejected as outliers. The accuracy of
the methods is obtained by comparing the
mean  recovery to the true values  of
concentration. The  range of accuracy
values (expressed as a percent relative
error) was from 0.13% to 17,720%. This
wide range was very dependent upon the
individual analyte with the highest error
being for zinc.
  The overall standard deviation indicates
the precision  associated with the meas-
urements generated by the 10 laborator-
ies. The overall precision (expressed as a
percent  relative  standard  deviation)
ranged from 0.55% to 171 %. The highest
relative standard deviation (worst preci-
sion) occurred for silver.
  Statistical comparisons of the effect of
water  type were  performed  on all an-
alytes. These  indicated  a practical effect
of water  matrix on the accuracy and/or
precision of the methods in the following
cases:
  Arsenic in effluents 2 and 3
  Beryllium in surface water
  Nickel in effluents 2 and 3
  Selenium in effluents 1 and 3
  Silver in effluent 2
  and  Thallium  in  surface  water and
    effluent 2

Conclusions and
Recommendations
  Statistically significant  matrix effects
were found for several methods. Accuracy
and precision were, in general, poorest
for the low concentration levels. Many
laboratories could not achieve the recom-
mended  method detection  limits.  For
several analytes accuracy and precision
for the highest concentration levels were
also  poor, indicating  that non-linearity
might not have been  detected by some
analysts. Environmental  contamination
with Al, Fe, and Zn affected the accuracy
and precision of these analyses. For four
of the six waters, zinc had the highest
percentage of data rejected. On average,
23% of  the  data were rejected.  For
individual laboratories,  data  rejection
ranged from  12% to 36%. From all of the
above it must be concluded that accurate
and precise results may be obtained only
by analysts thoroughly experienced in the
use of graphite furnace methods.
  It is  recommended  that instrumental
parameters such as graphite type, back-
ground correction, sheath gas, and use of
matrix modifiers be  specified so that
variability from these effects is minimized
and separated from sample matrix effects.
It is further  recommended that more
rigorous checks be made to determine if
the  method  of standard additions is
required  for  a particular  analyte/matrix
combination.

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 Table  1.    EPA Method Study—Trace Metals by AA. Regression Equations for Accuracy and Precision for Compound 1

 Water Type                     Aluminum                           Water Type                     Aluminum
Applicable cone, range

Lab pure water
Single-analyst precision
O verall precision
Accuracy

Drinking water
Single-analyst precision
Overall precision
Accuracy

Surface Water
Single-analyst precision
Overall precision
Accuracy

Water Type       	
(28.00-125.OO; iig/L
SR = 0.23X +  6.45
S  = 0.42X+  5.83
X  = 0.70C +32.36
SR = 0.72X+21.97
S  = 0.2SX + 14.45
X  =  1.IOC+ 39.21
SR = 0.33X+  5.29
S  =  O.SOX - 0.27
X  =  -0.34C + 33.60

Aluminum
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 3
Single-analyst precision
Overall precision
Accuracy
Water Type
(26.80-120.00) ug/L
SR = 0.23X+ 6.21
S = 0.42X +  5.80
X = 0.70C + 31.13
SR - 0.24X+ 3.18
S = 0.14X +26.59
X = 1.03C +32.88
                               Aluminum
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy

Water Type     	
(11.00-58.301 mg/L
SR = 0.36X -  2.87
S  = 0.39X -  2.27
X  = 0.85C +  1.87
SR = 0./6X +  0,88
S = 0.26X +  2.24
X =  1.12C-  2.89

Antimony
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 2
Single-analyst precision
Overall precision
Accuracy

Water Type    	
(0.46-2.18) mg/L
SR - 0.39X-  0.14
S = 0.39X -  0.09
X = 0.85C + 0.08
SR = -0.04X +  0.76
S = 0.07X+  0.18
X - 0.85C+  0.12

Antimony
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precis/on
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy

Effluent 2
Single-analyst precision
Overall precision
Accuracy

Effluent 3
Single-analyst precision
Overall precision
Accuracy

 Water Type
(10.50-230.00) ug/L
SR = 0.14X+ 1.09
S  = 0.40X +  0.88
X  = 0.65C +  0.56
SR = 0.24X-  0.50
S  = 0.17X +  3.89
X  = 0.88C-  1.28
SR = 0.72X +  4.23
S  = 0.09X +  9.56
X  = 0.73C +  5.80
SR - 0.22X +  0.37
S  = 0.33X +  0.87
X  = 0.61C+  0.31

Arsenic
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Drinking Water
Single-analyst precision
Overall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
                                      Water Type
(11.00-240.00) ug/L
SR = 0.23X +  0.02
5  = 0.34X +  0.86
X  = O.SOC - 2.66
SR = 0.21 X-  0.14
S  = 0.18X+  0.73
X  - 0.87C-  2.14
SR = 0.16X+  0.14
S  =  O.2OX +  0.87
X  =  O.81C-0.97
                               Arsenic
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent  1
Single-analyst precision
Overall precision
Accuracy
19.78-227.00) ug/L
 SR = 0.08X + 2.82
 S = 0.17X+  1.98
 X = 1.02C+  3.30
 SR = 0.07X +  5.85
 S = 0.15X+  4.01
 X = 1.15C + 8.87
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Drinking Water
Single-analyst precision
O verall precision
Accuracy
110.20-237.00) ug/L
 SR = 0./OX+ 0.70
 5 = 0.//X+  1.98
 X = 0.52C + 0.63
 SR = 0.06X +  1.96
 S = 0.12X+  1.49
 X = 0.93C +  0.62

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Table 1.    (Continued)
Water Type
                               Arsenic
                                      Water Type
                                                                                                    Arsenic
Applicable cone, range

Effluent 2
Single-analyst precision
Overall precision
Accuracy

Effluents
Single-analyst precision
Overall precision
Accuracy

Water Type	
(9.78-227.00) fjg/L
SR = 0.16X +0.97
S = 0.14X +3.70
X = 0.94C-0.68
SR = 0.07X + 0.53
S = 0.15X+2.56
X = 0.87C - 0.30

Barium
Applicable cone, range

Surface Water
Single-analyst precision
Overall precision
Accuracy
Water Type
/10.20-237.00) ug/L
SR = 0.09X + 0.80
S = 0.13X +2.75
X = 0.91C-1.29
Barium
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy

Effluent 2
Single-analyst precision
Overall precision
Accuracy

Effluent3
Single-analyst precision
Overall precision
Accuracy

Water Type     	
(56.50-418.00) ug/L
SR = 0.12X +4.80
S = 0.36X-8.62
X = 0.84C + 83.77
SR = 0.19X +70.20
S = 0.27X + 32.68
X = 0.97C + 67.43
SR = 0.29X-13.14
S  =  0.58X-27.91
X  =  0.84C + 42.52
SR = 0.69X-39.17
S = 0.34X + 9.88
X - 0.24C + 65.63

Beryllium   	
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Drinking Water
Single-analyst precision
0 verall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
Water Type
(59.10-437.00) ug/L
SR = 0.15X - 1.72
S  =  0.14X +75.63
X  =  0.84C + 30.67
SR = 0.11X +2.22
S  =  0.37X - 10.56
X  =  0.92C + 36.50
SR - 0.20X-0.16
S  =  0.28X + 7.58
X  =  0.93C + 30.17
Beryllium
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 1
Single-analyst precision
O verall precision
Accuracy

Effluent 2
Single-analyst precision
Overall precision
Accuracy

Effluents
Single-analyst precision
Overall precision
Accuracy

 Water Type    	
10.45-10.90) ug/L
SR = 0.7 2X + 0.05
S  = 0.29X + 0.05
X  - 1.15C-0.25
SR = 0.07X + 0.10
S  = 0.19X +0.20
X  - 0.92C + 0.11
SR = 0.12X-0.05
S  = 0.07X + 0.19
X  =  J.08C + 0.01
SR = 0.13X-0.00
S  - 0.20X + 0.08
X  = 0.92C - 0.03

 Cadmium
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Drinking water
Single-analyst precision
Overall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
 Water Type
10.47-11.40) ug/L
SR =  0.1 OX+ 0.08
S = 0.11X + 0.18
X = O.98C - 0.05
SR =  0.03X + 0.11
S  = 0.14X +0.07
X  = J.01C-0.07
SR = 0.7 OX+ 0.02
S  = 0.29X-0.08
X  = 0.90C + 0.10
 Cadmium
 Applicable cone, range

 Lab pure water
 Single-analyst precision
 Overall precision
 Accuracy
 (0.43-12.00J fjg/L
 SR = 0.09X + 0.25
 S = 0.17X + 0.20
 X = 1.02C + 0.24
 Applicable cone, range

 Lab pure water
 Single-analyst precision
 0 verall precision
 Accuracy
 (0.45-12.50) ug/L
 SR = 0.1 OX+ 0.05
 S = 0.27X-0.05
 X = 0.95C + 0.09

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 Table 1.    (Continued)
 Water Type
 Cadmium
 Water Type
                                                                                                     Cadmium
Applicable cone, range

 Effluent 1
 Single-analyst precision
 Overall precision
Accuracy

 Effluent 2
 Single-analyst precision
 Overall precision
Accuracy

 Effluent 3
 Single-analyst precision
 Overall precision
Accuracy

Water Type	
 (0.43-12.00) ug/L
 SR = 0.14X +0.42
 S = 0.32X^0.15
 X = 0.75C + 0.39
 SR = 0.12X + 0.09
 S = 0.23X + 0.07
 X = 0.81C + 0.15
 SR = 0.15X^0.04
 S = 0.27X^0.14
 X = 0.96C + O.JO

 Chromium
 Applicable cone, range

 Drinking water
 Single-analyst precision
 Overall precision
 Accuracy

 Surface water
 Single-analyst precision
 Overall precision
 Accuracy
 (0.45-12.50) ug/L
 Sft = 0.17X + 0.11
 S = 0.26X^0.10
 X = 0.92C + 0.24
 Water Type
 SR = 0.22X-0.13
 S = 0.38X^0.10
 X = 1.04C + 0.15
 Chromium
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy

Effluent 2
Single-analyst precision
Overall precision
Accuracy

Effluents
Single-analyst precision
Overall precision
Accuracy

Water Type	
(9.87-236.00) fjg/L
SR = 0.18X^0.73
S = 0.20X + 1.14
X - 0.89C+O.1J
SR = 0.14X^0,88
S = 0.21 X +3.87
X = 0.87C+7.09
SR = 0.17X-0.32
5 = 0.14X + 2.S5
X = 0.95C + 1.03
SR = O.oax + 0.28
S = 0.22X + 0.41
X = 0.92C - 0.68

Cobalt
Applicable cone, range

Lab pure water
Single-analyst precision
0 verall precision
Accuracy

Drinking water
Single-analyst precision
Overall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
Water Type
(10.30-246.00) ug/L
SR = 0.12X-0.41
S = 0.14X +0.35
X = 0.94C + 0.40
SR = 0.06X^2.73
S = 0.12X^4.14
X = /.OOC + 0.89
SR = 0.12X- 0.12
S - 0.26X - 0.04
X = 0.91 C +0.47
Cobalt
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Drinking water
Single-analyst precision
Overall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy

Water Type
129.70-420.00)/jg/L
SR = 0.09X + 0.50
S  =  0.25X - 2.99
X  =  0.88C + 1.36
SR = O.J2X+ 1.60
S  = 0.23X+ 1.24
X  = 0.92C + 0.44
SR - 0.14X- 1.00
S  = 0.18X-0.14
X  = 0.92C + 2.07

Cobalt
Applicable cone, range

Lab pure water
Single-analyst precision
O verall precision
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy
Water Type
(24.80-407.00) ug/L
SR = 0.1IX + 0.02
S  = 0.25*-2.69
X  = 0.89C+ 1.11
SR = 0.16X +0.58
S  = 0.20X-0.89
X  - 0.88C + 4.50
Cobalt
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy
(21.10-461.00) ug/L
SR = 0.09X + 0.03
S  = 0.25X- 1.99
X  = 0.89C + 0.25
Applicable cone, range

Lab pure water
Single-analyst precision
O verall precision
Accuracy
(29.30-435.00) ug/L
SR =  0.09X + 0.16
S  - 0.25X-3.31
X  - 0.88C + 1.32

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Table 1.    (Continued)

Water Type
Cobalt
Water Type
Cobalt
Applicable cone, range
Effluent 2
Single-analyst precision
O verall precision
Accuracy
Water Type
Applicable cone, range
(21. 10-461. 00) ijg/L
SR = 0.09X^3.21
S = 0.73X + 1.76
X = 0.95C + 0.43
Copper
(10.10-234.OO)/jg/L
Applicable cone, range
fffluent 3
Single-analyst precision
Overall precision
Accuracy
Water Type
Applicable cone, range
(29.30-435.00} ng/L
SR = 0.06X + 2.06
S = 0.1 5X + 1.28
X = 0.82C + 1.43
Copper
(0.30-1 .67) mg/L
Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy

Effluent 3
Single-analyst precision
O verall precision
Accuracy
SR = 0.07X + 4.37
S  = 0.11X + 4.97
X  = 0.92C-0.81
SR = 0.22X - 0.44
S  = 0.21X+ 1.21
X  = 0.96C-0.10
SR = 0.13X+ 1.95
S  = 0.29X + 4.96
X  = 0.81 C +0.42
Lab pure water
Single-analyst precision
0 verall precision
Accuracy

Effluent 2
Single-analyst precision
O verall precision
Accuracy
SR = 0.13X-0.02
S  = 0.13X-0.00
X  = 0.93C + 0.01
SR = 0.05X + 0.02
S  = 0.13X +0.01
X  =  1.02C - 0.07
Water Type
Copper
Applicable cone, range
(10.60-245.00) fjg/L
Lab pure water
Single-analyst precision
Overall precision
Accuracy

Drinking water
Single-analyst precision
Overall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
SR = 0.22X - 0.46
S  = 0.21 X+ 1.29
X  = 0.96C-0.77
SR = 0.15X +2.63
S  = 0.34X + 3.39
X  = 0.91 C +6.09
SR = 0.06X+1.18
S  = 0.18X +1.44
X  =  1.00C - 0.26
 Water Type
                                Iron
                                      Water Type
                                                                                                    Iron
Applicable cone, range
(26.10-455.00) ng/L
Applicable cone, range
(25.00-435.00) /jg/L
Lab pure water
Single-analyst precision
Overall precision
Accuracy

Drinking water
Single-analyst precision
Overall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
SR = 0.30X+26.73
S = 0.35X + 73.23
X = 1.40C+11.73
SR = 0.30X + 7.06
S = 0.36X + 9./5
X = 1.20C + 70.35
SR = 0.35X - 3.95
S = 0.34X + 37.42
X = 1.IOC+ 96.38
Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluents
Single-analyst precision
Overall precision
Accuracy
SR - 0.30X + 25.23
S = 0.35X+ 12.73
X = 1.41C+ 11.24
SR = 0.23X+16.21
S = 0.31X + 31.14
X = 1.09C + 37.18

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Table  1.    (Continued)

Water Type
Iron
 Water Type
                                                                     Iron
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy

Water Type	
(1.03-S.59) mg/L
SR = 0.04X^0.13
S = 0.05X + 0.27
X = 1.01C + O.07
 SR = 0.28X + 0.04
 S = 0.41X-0.13
 X = 1.16C-0.25

 Lead
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 2
Single-analyst precision
0 verall precision
Accuracy

Water Type
(0.37-2.61) mg/L
 SR = 0.06X + 0.03
 S = 0.07X + 0.08
 X = 1.42C-0.17
 SR = 0.18X-0.03
 S = 0.22X-0.01
 X = r.OOC + 0.04

 Lead
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy

Effluent 2
Single-analyst precision
Overall precision
Accuracy

Effluent 3
Single-analyst precision
Overall precision
Accuracy
(10.40-243.00) ug/L
SR = 0.17X-0.88
S = 0.17X+1.36
X = 1.06C-2.26
SR = 0.22X-0.14
S = 0.23X-0.06
X = 0.81 C + 2.05
SR = 0.14X+ 1.00
S = 0.22X+1.40
X = 0.86C-2.12
SR = 0.22X^1.48
S -  0.34X^1.86
X =  0.70C+ 1.63
Applicable cone, range

Lab pure water
Single-analyst precision
0 verall precision
Accuracy

Drinking water
Single-analyst precision
0 verall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
(10.90-254.00) ug/L
SR = 0.20X^0.42
S = 0.28X - 0.66
X = 0.83C + 1.35
SR - 0.07X + 1.39
S = 0.2 IX + 2.56
X - 0.85C + 0.50
SR = 0.19X^0.11
S - 0.18X +1.73
X - 0.92C - 0.96
Water Type
Applicable cone, range
Lab pure water
Single-analyst precision
O verall precis/on
Accuracy
Drinking water
Single-analyst precision
Overall precision
Accuracy
Manganese
(0.44-1 4.80) ug/L
SR
S =
X =
SR
S =
X =
= 0.27X + 0.31
0.44X + 0.48
1.00C+1.46
= 0.1 6X + 0.51
0.38X + 0.52
0.90C+ 1.38
Water Type
Applicable cone, range
Lab pure water
Single-analyst precision
Overall precision
Accuracy
Effluent 1
Single-analyst precision
Overall precision
Accuracy
Manganese
(91. 00-484.00) ug/L
SR
S =
X -
SR
S =
X =
= 0.03X+11.34
O.O5X + 1 1.20
0.55C + 12.98
= 0.04X + 40.27
0.1 IX + 32.01
0.97C - 6.66
Surface water
Single-analyst precision
0 verall precision
Accuracy
Water Type
Manganese
Water Type
Manganese
Applicable cone, range

Lab pure water
Single-analyst precision
0 verall precision
Accuracy

Effluent 2
Single-analyst precision
Overall precision
Accuracy
(111.00-666.00) ug/L
SR = 0.05X^8.13
S  = 0.07X + 9.19
X  = 0.93C + 9.38
SR = 0.26X + 3.47
S  = 0.32X - 6.30
X  = 0.78C-8.22
Applicable cone, range

Lab pure water
Single-analyst precision
O verall precision
Accuracy

£ffluent3
Single-analyst precision
Overall precision
Accuracy
(0.42-14.20) ug/L
SR = 0.27X + 0.37
S  = 0.43X + 0.47
X  =  1.00C+1.40
SR = O.23X + 0.52
S  = 0.48X - 0.28
X  = 0.46C + 2.56

-------
 Table  1.    (Continued)
Water Type
Nickel
                                      Water Type
                                Nickel
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy

Effluent 2
Single-analyst precision
Overall precision
Accuracy

Effluent 3
Single-analyst precision
Overall precision
Accuracy

Water Type
(26.20-461.00) ug/L
SR = 0.17X +0.34
S  - 0.26X + 1.89
X  = 0.84C + 6.46
SR = 0.1 OX+ 3.46
S  = 0.16X +4.72
X  = 0.67C + 70.56
SR = 0.13X + 2.39
S  = 0.24X + 5.60
X  = O.S5C-4.74
SR = 0.04X + 1.88
S  = 0.18X+ 9.11
X  = 0.84C - 9.99

Selenium
Applicable cone, range

Lab pure water
Single-analyst precision
O verall precision
Accuracy

Drinking water
Single-analyst precision
Overall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
                                      Water Type
(27.40-482.00) ug/L
SR = 0.21 X-2.45
S  =  0.23X + 1.98
X  =  0.93C - 2.02
SR = 0.12X +4.43
S  =  0.27X + 2.20
X  =  0.81 C +0.75
SR = 0.1 OX+ 4.38
S  =  0.16X +9.37
X  =  0.81 C +2.47
                                Selenium
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy

Effluent 2
Single-analyst precision
Overall precision
Accuracy

Effluent 3
Single-analyst precision
Overall precision
Accuracy

 Water Type	
(10.00-235.00) ug/L
SR = 0.06X + 0.65
S  =  0.17X + 0.14
X  =  0.93C - 0.20
SR = 0.05X + 3.19
S  = 0.19X+ 1.76
X  = 0.88C-2.45
SR = 0.1 IX+ 3.14
S  = 0.19X + 2.78
X  =  1.11C-2.78
SR - 0.17X +0.20
S  =  0.40X + 2.55
X  =  0.84C-2.14

 Silver
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Drinking water
Single-analyst precision
Overall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
 Water Type
(10.50-246.00) ug/L
SR = 0.1 OX+ 0.50
S  =  0.14X + 2.18
X  =  0.98C + 1.28
SR = 0.05X + 2.23
S  =  0.16X + 3.16
X  =  1.07C + 0.19
SR = 0.15X +0.25
S  =  0.17X+ 1.64
X  =  1.00C-0.66
                                                                      Silver
 Applicable cone, range

 Lab pure water
 Single-analyst precision
 Overall precision
 Accuracy

 Effluent  1
 Single-analyst precision
 Overall precision
 Accuracy

 Effluent  2
 Single-analyst precision
 Overall precision
 Accuracy

 Effluents
 Single-analyst precision
 Overall precision
 Accuracy
 (8.48-56.50) ug/L
 SR = 0.19X-0.95
 S = 0.17X + 0.35
 X = 0.79C + 2.78
 SR = 0.06X + 0.78
 S = 0.28X - 1.05
 X = 0.90C + 0.96
 SR = 0.28X+1.11
 S = 0.65X + 0.26
 X = 0.49C + 0.03
 SR = 0.34X-2.10
 S = 0.38X-1.06
 X = 0.70C + 4.27
 Applicable cone, range

 Lab pure water
 Single-analyst precision
 Overall precision
 Accuracy

 Drinking water
 Single-analyst precision
 Overall precision
 Accuracy

 Surface  water
 Single-analyst precision
 Overall precision
 Accuracy
 (0.45-13.60) ug/L
 SR = 0.15X +0.03
 S = 0.18X + 0.15
 X = 0.96C + 0.17
 SR = -0.02X + 0.77
 S = 0.20X + 0.17
 X = 0.82C + 0.81
 SR = 0.1 OX-0.07
 S = 0.56X + 0.06
 X = 0.87C + 2.46
                                        8

-------
Table  1.    (Continued)
Water Type
Thallium
                                      Water Type
                                Thallium
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy

Effluent 2
Single-analyst precision
Overall precision
Accuracy

Effluent 3
Single-analyst precision
Overall precision
Accuracy
(10.00-241.00)ijg/L
SR = 0.15X +0.03
S  = 0.12X +0.96
X  = 0.87C-1.24
SR = 0.09X + 0.41
S  = 0.30X - 0.04
X  = 0.76C- 1.12
SR = 0.16X-0.20
S = 0.14X+ 1.58
X = 0.62C- 1.06
SR = 0.06X + 0.00
S  = 0.19X +0.33
X  = 0.81 C-1.70
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Drinking water
Single-analyst precision
Overall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
(10.50-252.00)/jg/L
SR = 0.06X + 0.41
S  =  0.1 IX+ 0.13
X  =  0.88C-0.10
SR = 0.09X-0.29
S  =  0.26X- 1.14
X  =  0.89C - 0.89
SR = 0.1 OX+ 0.02
S = 0.25X-0.14
X = 0.84C-1.15
 Water type
 Vanadium
 Water type
 Vanadium
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Drinking water
Single-analyst precision
Overall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
(151.00-982.00) fig/7.
 SR = 0.12X + 2.14
 S = 0.53X-44.69
 X = 0.75C +26.06
SR = 0.04X + 21.95
S = 0.18X + 14.92
X = 1.00C-14.73
SR = 0.1 SX-5.47
S = 0.15X +0.56
X = 0.96C- 11.91
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 1
Single-analyst precision
Overall precision
Accuracy

Effluent 2
Single-analyst precision
Overall precision
Accuracy
(144.00-939.00)vg/L
 SR = 0.12X + 1.96
 S = 0.53X-42.61
 X = 0.75C +25.26
SR = 0.04X + 19.60
S = 0.24X + 4.39
X = 1.05C-7.45
SR = 0.13X+14.33
S = 0.11X+19.77
X = 0.94C-17.68
 Water type
 Vanadium
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy

Effluent 3
Single-analyst precision
O verall precision
Accuracy
(1.36-6.031 mg/L
SR = 0.05X + 0.01
S = 0.1 IX-0.01
X = 0.96C + 0.04
SR = 0.12X- 0.04
S = 0.21X-0.13
X = 0.99C-0.18
 Water type
Zinc
                                      Water type
                                Zinc
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy
(0.54-17.40) ug/L
SR = 0.56X- 1.19
S  =  1.03X-1.03
X  =  2.93C+J.02
Applicable cone, range

Lab pure water
Single-analyst precision
Overall precision
Accuracy
(1.31-6.41) mg/L
SR = 0.24X + 0.04
S  =  0.30X + 0.11
X  =  1.18C-0.31

-------
Table 1.    (Continued)

Water type
Zinc
Water type
                                                                Zinc
Applicable cone, range

Drinking water
Single-analyst precision
Overall precision
Accuracy

Surface water
Single-analyst precision
Overall precision
Accuracy
(0.54-17.40) fjg/L
SR = 0.31 X + 6.80
S = 0.99X + 0.69
X = 1.29C+14.50
SR = 0.59X-5.51
S = 1.06X-0.04
X = 2.43C + 7.16
Applicable cone range

Effluent 1
Single-analyst precision
Overall precision
Accuracy
(1.31-6.41 jmg/L
SR  = 0.35X + O.J9
S = 0.69X + 0.10
X = 0.42C + 0.84
Water type
Zinc
Water type
Zinc
Applicable cone, range
(24.60-189.00) ug/L
X = Mean recovery.
C = True value for the concentration.
Applicable cone, range
(0.51 -16.70) ug/L
Lab pure water
Single-analyst precision
Overall precision
Accuracy
Effluent 2
Single-analyst precision
Overall precision
Accuracy
SR = 0.24X+1.21
S = 0.31 X+ 1.45
X = 1. 11 C -2.76
SR = 0.86X- 19.95
S = 0.77X-3.46
X = 1.04C + 9.S8
Lab pure water
Single-analyst precision
O verall precision
Accuracy
Effluents
Single-analyst precision
Overall precision
Accuracy
SR
S =
X =
= 0.56X-J.04
1.00X-0.63
2.93C + 0.86
1.27X- 11.00
8.83C + 54.05
   T. R. Copeland and J. P. Maney are with ERCO, Cambridge, MA 02138.
   Edward L. Berg and Robert L. Graves are the EPA Project Officers (see below).
   The complete report, entitled "EPA Method Study 31: Trace Metals by Atomic
     Absorption (Furnace Techniques),"  (Order No.  PB 86-121  704/AS; Cost:
     $28.95, subject to change) will be available only from:
           National Technical Information Service
           5285 Port Royal Road
           Springfield, VA 22161
           Telephone: 703-487-4650
   The EPA Project Officers can be contacted at:
           Environmental Monitoring and Support Laboratory
           U.S. Environmental Protection Agency
           Cincinnati, OH 45268
                                     10
                                                                            •&U. S. GOVERNMENT PRINTING OFFICE: 1986/646-116/20749

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