United States
Environmental Protection
Agency
Environmental Monitoring and
Support Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S4-84-053 July 1984
-------
Phase II involved the selection of
participating laboratories. Solicitations
were made for paid participants and
volunteer participants. Selection of
laboratories was based on experience,
facilities, quality control procedures, and
cost estimates received from laboratories.
Final selection of 15 laboratories was
made after their successful analysis of
a performance sample. No laboratories
chose to participate in the study as
volunteers.
Phase III involved conducting the
formal method validation study. The
prepared ampules were distributed to
each laboratory. Individual laboratories
supplied the required four water types
(distilled water, tap water, surface water
and industrial effluent) into which the
ampules were to be spiked. As a separate
study, a single industrial wastewater was
supplied by Radian to evaluate the
analysis of a very diffucult sample
(including tendencies for false-positives
and false-negatives). After analyses,
results were reported on standard data
sheets. Data were keypunched and
validated by Radian. The final step in the
study was to conduct an analysis of all
data obtained using the IMVS computer
program.
Procedure
The design of the interlaboratory study
of Method 625 was based on the
nonreplicate technique by W.J. Youden.
According to this technique, samples
are prepared in pairs at several levels of
concentration where the concentration of
each analyte in a sample pair is slightly
different. The analyst is directed to
perform a single analysis and report one
value for each analyte in the sample.
Sample pairs for each method were
prepared at low, medium and high levels
within the linear range of the MS and
constituted three Youden pairs. However,
because of the number of analytes
present, the base/neutral-containing
ampules were divided into two groups of
three paris for a total of 12 separate
base/neutral ampules.
The samples were prepared as concen-
trates in sealed ampules and shipped to
the participating laboratories. Each
laboratory was responsible for supplying
laboratory pure water, finished drinking
water, a surface water, and an industrial
or municipal effluent water for each
concentrate to a volume of water from
each of the four water types and subse-
quently to analyze the spiked water
samples.
In addition to the sample ampules, an
industrial effluent water selected by
Radian was furnished to each participating
laboratory for analysis. This sample was
known to contain a number of the priority
pollutants and was judged to be difficult
to analyze. The purpose of the industrial
effluent sample was to evaluate Method
625 on false positive and false negative
results.
After analyses were completed, the
results were subjected to statistical
analyses using EPA's IMVS computer
programs to determine the precision and
accuracy of Method 625.
Results and Discussion
The objective of this interlaboratory
study was to characterize the performance
of Method 625 in terms of accuracy,
overall precision, single-analyst precision,
and the effect of water type on accuracy
and precision. Through statistical analy-
ses of 22,555 reported values, estimates
of accuracy and precision were made and
expressed in regression equations for
each compound. The equations shown in
Table 1-1 through 1-17 were based on
the 17,998 data values remaining after
eliminating outliers in the IMVS program.
Table 2 represents revised equations for
two compounds. The development and
interpretation of these regression equa-
tions are discussed in Section 5 of the
main report.
The accuracy is obtained by comparing
the mean recovery to the prepared values
of the concentrations and computing the
percent recovery. The mean recovery
statistics (at 100 A/g/L) for the base/neu-
tral compounds range from 21% for
dimethyl phthalate to 113% for isophorone.
The average recovery is 74%. Both of
these extremes are for the distilled water
matrix. The mean recovery for 3,3'-
dichlorobenzidine in the industrial efflu-
ent matrix is also 113%. One-half of the
mean recoveries for the base/neutral
compounds are between 61% and 87%,
with one-fourth of the mean recoveries
above and below these values. Recoveries
for dimethyl phthalate are consistently
low, ranging from 21% to 34%, for all
water matrices.
The mean recovery statistics (at 100
yug/L) for the acid compounds range from
44% for phenol to 106%for 2-nitrophenol
with an average value of 74%. These
extremes are for the distilled water and
are between 59% and 87%, with one-
fourth of the mean recoveries above and
below these values. Recoveries for 2-
nitrophenol are very good for all water
matrices with mean recoveries, ranging
from 91% to 106%. Mean recoveries for
phenol and 4-nitrophenol are consistently
low (probably due to loss of these
compounds into the base/neutral frac-
tion) with recoveries ranging from 44% to
48% and 54% to 60%, respectively. The
phthalates, particularly dimethyl and
diethyl phthalate, may have hydrolyzed
when the water samples were made
basic for the base/neutral extraction,
thus contributing to low recovery. In
general, one would expect the lower
molecular weight phthalate esters to
hydrolyze more rapidly than the higher
molecular weight esters. The high overall
recoveries for isophorone could be
partially due to the poor chromatography
of this compound on the packed GC
column, contributing to nonlinear response
in the mass spectrometer.
The overall standard deviation of the
analytical results is an indication of the
precision associated with the measure-
ment generated by a group of laboratories.
The percent relative standard deviation
(RSD) at 100/yg/L for the base/neutral
compounds range from 10% for phenan-
threne in the tap water matrix to 104% for
dimethyl phthalate in the surface water
matrix with a median value of 35%.
Precision for dimethyl phthalate is poor
for all water matrices with RSDs ranging
from 88% to 104%. One-half of the RSDs
for the base/neutral compounds are
between 26% and 52%. In 95% of the
cases, the RSDs are less than 76%. The
RSDs (at 10Ofjg/L) for the acid compounds
range form 21% for 2,4,6-trichlorophenol
in the tap water matrix to 91% for 2,4-
dinitrophenol in the distilled water matrix
with a median RSD of 32%. Precision for
2,4-dinitrophenol is poor for all water
matrices with RSDs ranging from 68% to
91%. One-half of the RSDs for the acid
compounds are between 27% and 47%.
In 95% of the cases the RSDs are less
than 73%.
The percent relative standard deviation
for a single analyst (RSD-SA) indicates
the precision associated with a single
laboratory. The RSD-SA for base/neu-
tral samples at 100/jg/L ranges from 8%
for 2-chloronaphthalene in the distilled
water matix to 72% for dimethyl phthalate
in the surface water matrix, with a
median RSD-SA of 24%. With the
exception of the tap water matrix, single-
analyst precision for dimethyl phthalate
is poor with RSD-SAs ranging from 55%
to 72%. One-half of the RSD-SAs for the
base/neutral compounds at 100/ug/Lare
between 18% and 34%. In 95% of the
cases, the RSD-SAs are less than 51%.
The RSD-SAs (at 100 fjg/L) for the acid
compounds range from 12% for 2,4,6-
trichlorophenol in the industrial effluent
matrix to 45% for 2,4-dinitrophenol in the
tap water matrix with a median RSD-SA
-------
Table 1-1. Regression Equations for Accuracy and Precision for Compounds 1
Water Type Acenaphthene Acenaphthylene
Applicable Cone. Range -ug/L
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
(7.0 - 400.0)
SR = 0. 15X - 0. 12
S =0.21X-0.67
X =0.960 + 0.19
SR = 0.09X + 0.56
S =0.17X + 0.10
X = 0.95C + 0.08
SR = 0.21 X -0.60
S =0.27X-0.02
X =0.910-0.02
SR = 0. 15X - 0.07
S = 0.1 8X+ 0.38
X =0.850 + 0.46
(8.0 - 450.0)
SR = 0.24X - 1.06
S =0.26X-0.54
X =0.890 + 0.74
SR = 0.1 6X + 0.37
S = 0.23X - 0.25
X = O.87C + O.48
SR = 0.14X -0.01
S =0.21X + 0.67
X = 0.970 + 0.24
SR = 0.13X - 0.35
S = 0.25X - 0.44
X =0.880-0.03
Aldrin
(11.0- 600.0)
SR = 0.27X - 1.28
S = 0.43X + 1. 13
X =0.780+1.66
SR = 0.28X - 0.48
S = 0.47X - 0.92
X = O.66C + O.S8
SR = 0.36X - 1.64
S = 0.52X - 1.01
X = 0.550 + 7.00
SR = 0.38X + 0.17
S =0.59X + 0.08
X =0.520 + 0.80
Anthracene
(5.0 - 600.0)
SR = 0.21X -0.32
S =0.27X-0.64
X =0.80.0 + 0.68
SR = 0.15X -0.17
S =0. 19X - 0.07
X = 0.820 + 0.42
SR = 0. 18X + 0.02
S =0.24X-0.11
X =0.810 + 0.55
SR = 0.1 7X -0.03
S =0.29X + 0.13
X =0.740 + 0.88
X = Mean Recovery
C = True Value for the Concentration
Tablet-2. Regression Equations for Accuracy and Precision for Compounds 5
Water Type
B-BHC
Applicable Cone. Range -ug/L (14.0 - 750.0)
Distilled Water
Single-Analyst Precision
Overall Precision
A ccuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
X = Mean Recovery
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.20X
= 0.30X
= 0.870
= 0. 16X
= 0.22X
= 0.810
= 0. 15X
= 0.23X
= 0.800
= 0.17X
= 0.25X
= 0.840
-0.58
- 1.94
-0.94
-0.14
-0.77
-0.43
-0.72
-0.39
-0.44
-0.16
-0.23
-0.89
Benzo(A)Anthracene
(18.0 - 400.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0. 15X +
= 0.26X -
= 0.88C -
= 0. 19X +
0.93
0.28
0.60
4.78
= 0.26X+2.49
= 0.800 +
= 0.32X -
= 0.36X -
= 0.710 -
= 0.43X -
= 0.53X -
= 0.630 -
1.14
1.44
0.63
0.22
1.81
0.46
0.79
BenzofA/Pyrene
(5.0 - 6OO.O)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.22X + 0.48
= 0.32X + 1.35
= 0.900-0.13
= 0.33X + 0.38
= 0.40X+0.35
= 0.790-0.95
= 0.39X + 0.75
= 0.45X+0.71
= 0.680-0.04
= 0.41X-0.12
= 0.65X + 0.09
= 0.560-0.26
Benzo(B)Fluoranthene
(11
SR
S
X
SR
S
X
SR
S
X
SR
S
X
.0 - 6OO.O)
= 0.22X +
0.43
= 0.29X + 0.96
= 0.93C •
= 0.32X +
= 0.45X +
= 0.700 -
= 0.35X-
1.80
1.01
1.04
1.73
0.42
= 0.42X + 0.82
= 0.660 -
= 0.41X-
= 0.62X -
= 0.560 -
1.40
0.40
0.08
0.48
C = True Value for the Concentration
Table 1-3. Regression Equations lor Accuracy and Precision lor Compounds 9
Water Type
Bis(2-Chloroethyl)Ether
Di-N-Butylphthalate
DibenzofA.HJA nthraccne
Diethyl Phthalate
Applicable Cone. Range -ug/L
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
(14.0 - 750.0)
SR = 0.35X - 0.99
S =0.35X + 0.10
X =0.860 - 1.54
S ••
X '•
SR--
S ••
X ••
SR--
S '•
X ••
-0.25X+ 1.49
--0.27X+ 1.79
-- 0.870 - 2.52
-- 0.26X - 1.07
= 0.32X + 0.58
-- 0.890 - 1.02
--0.21X+3.15
= 0.34X + 0.69
•-0.910-0.72
(6.0 - 700.0)
SR = 0.13X + 0.16
S =0.39X+0.60
X =0.590+0.71
SR = 0.24X + 0.19
S =0.34X-0.12
X =0.590 + 0.40
SR = 0.27X - 0.69
S = 0.34X + 0.84
X =0.600+ 1.83
SR = 0.23X + 0.32
S = 0.47X - 0.18
X =0.580 + 0.42
(9.0 - 400.0)
SR =0.30X + 8.51
S = 0.59X + 0.25
X =0.880 + 4.72
SR = 0.38X + 0.17
S =0.55X-0.26
X =0.850-4.72
SR = 0.37X - 0.02
S = 0.50X + 0.13
X = 0.640 - 1.44
SR = 0.45X - 0.76
S = 0.86X - 0.49
X = 0.63C - 2.51
(6.0 - 700.0)
SR=0.28X+ 1.44
S =0.52X + 0.22
X =0.430+1.00
SR=0.34X + 0.11
S =0.65X-0.20
X =0.430 + 0.37
SR = 0.40X + 0.77
S = O.SOX+ 0.44
X =0.510+1.29
SR = 0.33X - 0.05
S = 0.45X + 0.20
X = 0.570 • 0.19
X = Mean Recovery
C = True Value for the Concentration
-------
Table 1-4. Regression Equations for Accuracy and Precision for Compounds 13
Water Type
Applicable Cone. Range -ug/L
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precis/on
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
Endosulfan Sulfate
(14.0 - 750.0)
SR = 0.1 2X + 2.47
S = 0.63X- 1.03
X = 0.390 + 0.41
SR = 0.20X + 1.28
S =0.66X-0.60
X =0.68C-4.82
SR = 0.22X - 0.86
S =0.67X-2.55
X =0.63C - 1.95
SR = 0.40X - 0.24
S =0.70* -0.34
X =0.650-4.67
Fluoranthene
16.0 - 700.0)
SR -0.22X-0.73
S -0.28X-0.60
X = 0.81C + 1.10
SR = 0.12X + 0.93
S = 0.22X + 0.12
X =0.760 + 0.84
SR = 0.23X - 0.70
S = 0.29X - 0.64
X = 0.71C + 1.15
SR = 0.1 9X+ 0.73
S =0.36X + 0.17
X = 0.68C + 1.53
Heptachlor
(11.0-600.01
SR = 0.24X - 0.56
S = 0.50X-0.23
X = 0.87C - 2.97
SR = 0.37X - 0.68
S =0.44X-0.17
X =0.730-2.31
SR=0.38X- 1.70
S =0.50X-1.20
X =0.730-2.07
SR = 0.39X - 0.95
S = 0.49X + 0.09
X =0.680-1.44
Hexachlorobenzene
(6.0 - 535.0)
SR=0.18X-0.10
S = 0.43X - 0.52
X = 0.74C + 0.66
SR = 0.25X + 0. 15
S = 0.30X + 0,19
X =0,720 + 0.20
SR = 0.23X - 0.52
S =0.32X-0.22
X = 0.69C + 0.65
SR=0.17X + 0.14
S =0.38X-0.52
X = 0.58C + 0.22
X = Mean Recovery
C = True Value for the Concentration
Table 1-5. Regression Equations for Accuracy and Precision for Compounds 17
Water Type
Isophorone
Applicable Cone. Range -ug/L (5.0 '- 600.0)
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
X = Mean Recovery
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.27X+0.77
= 0.33X +
= 1.12C +
= 0.30X-
= 0.52X -
= 1.10C +
= 0.20X +
= 0.35X +
0.26
1.41
0.22
0.34
2.07
1.36
0.94
= 1.05C + 0.65
= 0.42X -
3.27
= 0.57X + 0.64
= 1.00C +
9.41
Naphthalene
(6.0 - 700.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.21X -
= 0.30X-
= 0.76C +
= 0. 18X -
= 0.24X -
= 0.77C +
= 0.24X -
= 0.27X -
= 0.78C +
= 0.20X-
= 0.33X •
= 0. 70C +
0.41
0.68
1.58
0.36
0.34
1.28
0.84
0.09
1.39
0.18
0.51
1.82
PCB-1260
(36.0 - 667.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.35X + 3.61
= 0.43X +
= 0.81C -
= 0.50X -
1.82
10.86
2.60
= 0.51X + 4.39
= 0.68C -
= 0.72X -
= 0.65X-
= 0.51C -
= 0.43X +
= 0.57X -
= 0.46C -
17.11
4.51
1.11
11.95
2.02
0.49
12.56
1 ,3-Dichlorobenzene
(5.0 - 600.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.25X + 0,68
= 0.41X + 0.11
= 0.86C-0.70
= 0.24X + 0.90
= 0.42X - 0.03
= 0.89C - 1.10
= 0.32X + 0. 14
= 0.34X-0.15
= 0.92C - 0.86
= 0.33X + 0.49
= 0,41 X + 0,73
= 0.79C -0.27
C = True Value for the Concentration
Table 1 -6. Regression Equations for Accuracy and Precision for Compounds 21
Water Type
2, 6-Dinitrotoluene
Applicable Cone. Range -ug/L (11.
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
X = Mean Recovery
SR
S
X
SR
S
X
SR
S
X
SR
S
X
0 - 600.0)
= 0.14X+ 1.26
= 0. 19X + 0.35
= 1.06C - 3.60
= 0.1 8X + 0.20
= 0.21 X- 0.01
= 1.02C - 2.81
= 0.20X + 0.75
= 0.26X + 2.25
= 1.06C - 3.52
= 0.27X - 1.66
= 0.31X + 0.53
= 1.05C - 1.78
3, 3-Dichlorobenzidine
(36.0 - 667.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.28X +
7.33
= 0.47X + 3.45
= 1.23C •
= 0.23X +
= 0.44X +
= 1.11C-
= 0.65X -
= 0.70X-
= 1.22C -
= 0.23X +
= 0.42X +
= 1.33C -
12.65
4.38
5.46
12.56
11.31
9.34
20.68
7.55
0.78
20.41
4-Chlorophenyl Phenyl Ether 4.4 -ODD
(9.0 - 500.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.20X -
= 0.30X -
= 0.91C +
= 0. 15X -
= 0.25X -
= 0.95C +
= 0. 15X -
= 0.25X -
0,94
0.46
0.53
0.28
0.26
0.04
0.43
0.68
= 0.97C + 0.65
= 0.19X-
= 0.35X -
0.20
1.34
= 0.81C + 0.42
(7.0 - 400.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.29X
= 0.66X
= 0.56C
-0.32
-0.96
-0.40
= 0.31 X + 0.64
= 0.55X
= 0.54C
= 0.45X
= 0.68X
-0.33
- 0.16
- 1.47
- 1.33
= 0.49C + 0.31
= 0.45X
= 0.58X
= 0.46C
-0.55
-0.79
-0.38
C = True Value for the Concentration
-------
Table 1-7. Regression Equations for Accuracy and Precision for Compounds 25
Water Type
4,4 -DDE
Applicable Cone. Range
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
(14.0 - 750.0)
SR=0.26X-1.17
S =0.39X-1.04
X =0.700-0.54
SR=0.35X+0.38
S =0.38X-O.J4
X =0.570-0.28
SR = 0.21 X-0.44
S =0.39X-1.06
X =0.470-0.30
SR =0.39X^0.37
S =0.49X-0.47
X =0.470 + 0.03
X = Mean Recovery
0 = True Value for the Concentration
Table 1-8. Regression Equations for Accuracy and Precision for Compounds I
Water Type
BenzofG, H. l)Perylene
Benzo(K)Fluoranthene
Benzyl Butyl Phthalate
X = Mean Recovery
C = True Value for the Concentration
Bis(2-Chloroethoxy)Methane
Applicable Cone. Range -ug/L (7.4 - 232.0)
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.29X +
= 0.51X -
= 0.980 -
= 0.43X -
= 0.54X -
= 0.700 -
2.40
0.44
0.86
1.02
0.85
1.79
= 0.47X^0.39
= 0.64X -
= 0.65C -
= 0.35X -
= 0.68X -
= 0.600 -
0.53
2.98
0.02
0.12
1.71
(7.2 - 548.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.19X + 1.03
= 0.35X + 0.40
= 0.87C - 1.56
= 0.20X-0.17
= 0.36X + 0.35
= 0.65C -0.64
= 0.39X^0.69
= 0.55X*0.48
= 0.630-0.44
= 0.27X*0.89
= 0.64X^0.22
= 0.54C + 0.55
(7.2 - 548.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.18X*0.94
= 0.53X*0.92
= 0.66C - 1.68
= 0.17X^2.17
= 0.52X + 1.34
= 0.61 C - 0.26
= 0.51 X - 0.33
= 0.61 X+ 0.29
= 0.52C - 0.65
= 0.51 X - 0.39
= 0.57X*0.75
= 0.620 + 0.21
{} 1.0 -646.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.16X + 1.34
= 0.26X^2.01
= 1.12C - 5.04
= 0.15X^2.85
= 0.26X^2.75
= 1.05C - 4.58
= 0.32X -0.34
= 0.33X + 1.28
= 0.95C - 2.98
= 0.23X^2.70
= 0.30X + 1.76
= t.OJC + 0.12
Table 1-9. Regression Equations for Accuracy and Precision for Compounds 5
Water Type
Bis(2-Chloroisopropyl)Ether
Bis(2-EthylhexyltPhthalate
Chrysene
D-BHC
Applicable Cone. Range -ug/L (14.0 - 508.0)
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
SR = 0.24X + 0.28
S = 0.25X + 1.04
X = 1.03C - 2.31
SR = 0.15X + 1.23
S = 0.28X^0.70
X =0.93C - 1.95
SR = 0.33X - 1.59
S = 0,30X + 1.21
X = 0.85C + 0.87
SR = O.12X + 0.88
S = 0.21X^0.09
X =0.950*0.13
(7.2 - 548.0)
SR = 0.26X + 0.73
S =0.36X^0.67
X =0.840-1.18
SR = 0.27X + 0.50
S =0.48X^0.44
X =0.63C-2.33
SR = 0.39X - 0.45
S =0.49X-0.17
X =0.510-1.81
SR = 0.32X^0.69
S =0.64X^0.13
X =0.520-0.94
(5.4 -411.0)
SR = 0.28X^0.13
S =0.33X-0.09
X = 0.93C - 1.00
SR = 0.17X^0.80
S = 0.25X + 0.62
X = 0.80C - 0.55
SR = 0.35X - 0.14
S = 0.44X - 0.21
X = 0.62C + 0.16
SR = 0.33X + 0.28
S =0.52X^0.14
X =0.66C + 0.27
(7.2 - 547.0)
SR= 0.34X^0.86
S =0.93X-0.17
X = 0.290 - 1.09
SR = 0.20X + 0.75
S =0.91X-0.14
X =0.350-0.75
SR =0.62X -2.52
S =0.90X-0.67
X =0.330-0.91
SR = 0.32X + 0.95
S =0.78X-0.35
X =0.420*0.23
X = Mean Recovery
C = True Value for the Concentration
-------
Table 1-10. Regression Equations for Accuracy and Precision lor Compounds 9
Water Type
Di-N-Octylphthalate
Applicable Cone. Range -ug/L (7.2 - 548.01
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
X = Mean Recovery
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.21X +
= 0.37X +
= 0.760 -
- 0.26X +
1.19
1.19
0.79
0.52
= 0.53X+0. JO
= 0.550 -
= 0.45X -
= 0.57X-
= 0.57C-
= 0.32X +
= 0.75X +
= 0.490-
2.26
0.59
0.26
1.69
0.65
0.09
1.30
Dieldrin
17.2 - 548.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.20X -
= 0.26X -
= 0.820 -
= 0.20X -
= 0.29 X -
= 0.710 +
= 0.26X -
= 0.32X -
0.16
0.07
0.16
0.46
0.84
0.47
0.88
0.92
= 0.690 + 0.84
= 0.26X -
= 0.33X-
= 0.670 +
0.18
0.23
1.29
Dimethyl Phthalate
(4.5 - 343.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.54X + 0.19
= 1.05X - 0.92
= 0.20C + 1.03
= 0.27X + 0.08
= 1.01X - 0.26
= 0.300 - 0. 13
= 0.75X -0.98
= 1.07X - 0.88
= 0.29C + 0.50
= 0.70X-0.35
= 0.89 X - 0.39
= 0.350-0.63
Endrin Aldehyde
(22.0 - 658.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0, 18X +
= 0.73X-
= 0.76C-
= 0.38X-
= 0,65X +
= 0,590 -
= 0. J5X +
= 0.66X -
= 0.600 +
= 0.46X -
3.91
0.62
3.86
0.02
C.32
4.02
2.12
1.32
0.78
2.89
= 0.74X + 0.92
= 0.57C -
1.58
C - True Value for the Concentration
Table 1-11. Regression Equations for Accuracy and Precision for Compounds 13
Water Type
Applicable Cone. Range -ug/L
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
X = Mean Recovery
Fluorene
(5.4-
SR =
o —
x =
SR =
S =
X =
SR =
S =
X =
SR =
S =
X =
411.0)
0. 12X +
0. 13X +
0.900 -
0.26
0.61
0.00
0.10X + 0.53
0.13X +
0.830 +
0.23X -
0.27X -
0.780 +
0. 14X +
0.56
0.30
0.47
0.20
0.30
1.20
0.25X + 0.92
0.720 +
1.26
Heptachlor Epoxide
17.2 •
SR =
S =
X =
SR =
S =
X =
SR =
S =
X =
SR =
S =
X =
• 548.0)
0.33X -
0.28X +
0.920 -
0.1 6X +
0.36X -
0.880-
0.24X -
0.35X -
0.850 -
0.42X +
0.46
0.64
1.87
0.55
0.15
1.80
0.08
0.18
0.69
0.15
0.42X + 0.05
0.690-
1.03
Hexachlorobutadiene
(9.0 -
SR =
S =
X =
SR =
S =
X =
SR =
S =
X =
SR =
S =
X =
685.01
0. 19X +
0.26X +
0.710-
0.92
0.49
1.01
0.16X+0.85
0.16X +
0.63 C -
1.22
0.74
0.19X + 0.09
0.21X +
0.620 -
0.23X +
0.28X +
0.87
0.10
0.88
1.06
0.590 + 0.11
Hexachloroethane
(6.3-
SR =
S =
X =
SR =
S =
X =
SR =
S =
X =
SR =
S =
X =
480.0)
0.17X + 0.67
0.17X + 0.80
0.730 - 0.83
0.2JX + 0.60
0.21X + 0.56
0.680 - 0.23
0.29X - 0.54
0.26X + 0.44
0.690-0.70
0.20X + 0.39
0.23X+ 1.02
0.69C - 0.24
C = True Value for the Concentration
Table 1-12. Regression Equations for Accuracy and Precision for Compounds 17
Water Type
lndeno(1,2.3-C.D)Pyrene
N-Nitrosodi-N-Propylamine Nitrobenzene
Phenanthrene
Applicable Cone. Range -ug/L (7.4 - 292.0)
Distilled Water
Single-Analyst Precision SR = 0.29X + 7.46
Overall Precision S =0.50X^0.44
Accuracy X =0.780-3.10
Tap Water
Single-Analyst Precision SR = 0.26X + 0.18
Overall Precision S =0.50X^0.57
Accuracy X = 0.580 - 2.55
Surface Water
Single-Analyst Precision SR = 0.53X - 0.20
Overall Precision S =0.57X^0.21
Accuracy x =0.490-1.73
Industrial Effluent
Single-Analyst Precis/on SR = 0.36X + 0.49
Overall Precision S =0.60X^0.08
Accuracy X =0.540-1.91
(18.0 - 527.0)
SR = 0.27X + 0.68
S =0.44^ + 0.47
X =1.120-6.22
SR = 0.30X + 3.39
S =0.44X^2.69
X = 7.09C - S. 78
SR = 0.43X - 3.07
S = 0.55X - 3.33
X = 1.030 - 3.35
Sff = 0.36X+ 7.77
S =0.47X^1.52
X =0.880*0.64
(9.0 - 685.0)
SR = 0.19X^0.92
S =0.27^ + 0.27
X = 7.09C - 3.05
SR = 0.14X^0.92
S =0.28X + 0.81
X = 1.010 -3.19
SR = 0.34X - 2.25
S =0.34X^0.84
X =0.970 - 1.13
SR = 0,18X+ 1.58
S = 0.34X - 0.7 7
X =1.010-2.70
(9.0 - 685.0)
SR = 0.12X^0.57
S =0.15X^0.25
X =0.870-0.06
SR = 0.09X - 0.04
S =0.10X^0.23
X =0.780 + 0.73
SR = 0.16X -0.24
S =0.19X-0.35
X =0.750+ 1.40
SR = 0.12X +0.94
S =0.29^-0.06
X =0.810+1.08
X = Mean Recovery
C = True Value for the Concentration
-------
Table 1-13. Regression Equations for Accuracy and Precision for Compounds 21
Water Type Pyrene 1.2-Dichlorobenzene
Applicable Cone. Range -ug/L (4.5 - 343.0)
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
SR
S
X
SR
S
X
SR
S
X
= 0.16X +
= 0. 15X +
= 0.840 -
= 0.10X +
= 0. 73X +
= 0. 76C -
= 0.16X -
= 0. 18X +
= 0.730 +
0.06
0.31
0.16
0.22
0.50
0.06
0.17
0.26
0.39
SR = 0.17X + 0.16
S
X
= 0.36X +
= 0.690 +
0.51
1.52
(5.4 - 411.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.20X + 0.47
= 0.24X +
0.39
= 0.80C + 0.28
= 0.17X +
= 0.25X +
= 0.780 +
= 0.28X -
= 0.25X +
= 0.750 +
= 0.25X -
= 0.35X +
= 0. 730 +
7.00
0.93
0.54
0.36
7.46
7.78
0.05
0.26
7.27
1 ,2,4-Trichlorobenzene
(10.0 - 622.01
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0. 15X + 0.85
= 0.27X + 0.39
= 0.940-0.79
= 0.1 6X + 0.11
= 0.23X + 0.67
= 0.800 - 0.04
= 0. 19X + 0.27
= 0.20X+ 1.60
= 0.780 + 0.44
= 0.13X+ 1.04
= 0.24X + 0.48
= 0.810 + 0.01
1.4-Dichlorobenzene
(1 7.0 - 646.0;
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.24X +
= 0.29X +
= 0.73C-
0.23
0.36
7.47
= 0.78X + 0.03
= 0.32X -
= 0.75C-
= 0.30X -
= 0.37X-
= 0.6SC -
= 0.22X +
0.00
1.90
1.14
0.19
1.37
0.21
= 0.30X + 0.75
= 0.70C-
0.65
X = Mean Recovery
C = True Value for the Concentration
Table 1 -14. Regression Equations for Accuracy and Precision for Compounds 25
Water Type
2-Chloronaphthalene
Applicable Cone. Range -ug/L (4.5 - 342. Oj
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.07X + 0.52
= 0.1 3X + 0.34
= 0.89C + 0.07
= 0.70X + 0.32
= 0.74X + 0.49
= O.S5C + 0.03
= 0.24X + 0.2S
= 0.24X + 0.42
= 0.79C + 0.36
= 0. 75X + 0.24
= 0.23X -0.05
= 0.820 + 0.63
2.4
(11
SR
S
X
SR
S
X
SR
S
X
SR
S
X
-Dinitrotoluene
.0 - 646.01
= 0. 12X +
= 0.27X +
= 0.92C -
= 0. 18X +
= 0.27X +
= 0.83C -
= 0.21X +
= 0.31X +
= 0.83C -
= 0.11X +
= 0.1 IX +
= 0.93C -
1.06
1.50
4.81
0.89
2.08
2.57
0.46
1.03
2.91
2.28
2.41
0.64
4-Bromophenyl Phenyl Ether 4.4
(7.2 - 548.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0. 13X +
0.66
= 0.76X + 0.66
= 0.97C-
7.34
= 0.1 5X + 0.23
= 0.17X +
= 0.85C -
= 0.16X +
= 0. 14X +
= O.S3C -
= 0.27X +
= 0.30X +
= 0.72C-
0.88
1.21
0.22
1.26
0.58
0.50
0.02
0.19
-DDT
(7.0 - 548.0)
SR
S
X
SR
S
X
SR
S
X
SR
S
X
= 0.42X + 0. 79
= 0.65X
= 0. 79C
= 0.57X
= 0.6SX
= 0.66C
= 0.60X
= 0.64X
= 0.56C
= 0.46X
= 0.77X
= 0.53C
-0.5S
-3.2S
- 0.64
-0.54
-2.77
- 7.76
-0.07
-2.73
-0.30
-0.42
-2.72
X = Mean Recovery
C = True Value for the Concentration
Table 1-15. Regression Equations for Accuracy and Precision for Compounds 1
Water Type
Pentachlorophenol
Phenol
2-Chlorophenol
2-Methyl-4.6-Dinitrophenol*
Applicable Cone. Range -pg/L (13.0 - 480.0)
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
SR = 0.24X + 3.03
S =0.30X + 4.33
X = 0.93C + 7.99
SR = 0.38X - 0.69
S =0.38X+3.79
X = 0.82C + 3.68
SR = 0.19X + 0.33
S = 0.30X + 2.10
X =0.85C + 2.89
SR = 0.18X+ 1.09
S =0.26X + 4.51
X =0.73C + 3.38
(6.0 - 467.01
SR = 0.26X + 0.73
S =0.35X^0.58
X = 0.43C + 7.26
SR = 0.24X+ 1.50
S =0.43X^0.64
X =0.44C+ 1.14
SR = 0.23X + 0.47
S =0.28X+0.63
X =0.470+1.11
SR = 0.27X -0.19
S =0.35X-0.05
X =0.44C+1.37
(7.0 - 533.0)
SR = 0.18X+ 1.46
S =0.28X + 0.97
X =0.78C + 0.29
SR = 0.23X + 0.77
S =0.32X + 0.27
X =0.750 + 0.16
SR = 0.17X + 0.16
S = 0.24X - 0.76
X =0.750-0.07
SR = 0.14X -0.35
S =0.21X + 0.48
X =0.720 + 0.63
(72.0 - 1067.0)
SR = 0.22X + 9.86
S =0.30X+ 77.37
X = 7.05C - 33.88
SR = 0.26X + 9.38
S =0.36X+ 77.44
X = 0.99C - 28.14
SR = 0.24X -2.78
S =0.40X + 6.33
X =1. IOC -22.92
SR = 0.23X - 5.99
S = 0.41 X +3.52
X = 1.01C - 14.22
\ X = Mean Recovery
C = True Value for the Concentration
'Revised regression equations and estimates of accuracy and precision are given in Table 13
-------
Table 1-16. Regression Equations lor Accuracy and Precision for Compounds 5
Wafer Type
Applicable Cone. Range -ug/L
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
A ccuracy
2-Nitrophenol
114.0
S =
V —
S =
X =
S =
X =
SR =
S =
X =
- 520.0)
0.16X + 1.94
0.27X+ 2.60
1.07C - 1.15
0. 19X + 7.93
0.24X + 2.32
0.95C - 0.46
0.1 7X + 0.24
0.26X + 2.27
0.97C -0.78
0. 75* + 0.77
0.33X + 1.66
0.90C+0.78
2. 4 -Dichlorophenol
(8,0 - 600.01
SR =
S =
X =
S =
X =
SR =
S =
X =
S =
X =
0.1 5X + 1.25
0.21X+ 1.28
0.87C + 0.13
0. 79* +0.67
0.24X + 1.00
0.82C + 0.57
0.1 4X + 0.33
0.22X + 0.82
0.89C + 0.01
0.17X-0.24
0.23X+0.46
0.81C+0.61
2.4-Dimethylphenol
19.0 •
S =
X =
S =
X =
S =
X =
SR =
S =
X =
• 667.0)
0.1 6X + 1.21
0.22X+ 1.31
0.71C + 4.41
0.24X + 0.71
0.38X+ 1.71
0.58C+ 1.13
0.30X - 0.58
0.41X-0.41
0.62C + 2.10
0.29X + 0. 10
0.59X-0.15
0.49C+ 1.91
2,4-Din/trophenol''
(90.0
SR =
S =
X =
SR =
S =
X =
SR =
S =
X =
SR =
S =
X =
- 7333.0;
0.3SX + 2.39
0.42* + 26.26
7.55C - 700.90
0.33X+6.1S
0.48X + 13.01
1.48C - 98.47
0.28X+ 1.15
0.30X + 26.92
7.56C - 85.38
0.25X + 6.45
0.36X + 22.05
1.24C -54.41
X = Mean Recovery
C = True Value for the Concentration
"Revised regression equations and estimates of accuracy and precision are given in Table 13
Table 1-17. Regression Equations for A ccuracy and Precision for Compounds 9
Water Type
Applicable Cone. Range -fjg/L
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
X = Mean Recovery
C = True Value for the Concentration
2, 4. 6- Trichlorophenol
(11.9 -440.0)
SR = 0. 16X + 2.22
S =0.22X^1.81
X = 0.91 C- 0.18
SR = 0. 17X+ 2.35
S = 0.1 9X+ 1.85
X =0.fiSC+ 1.26
SR = 0.16X^0.42
S =0.28X^0.92
X =0.88C-0.36
SR = 0.08X + 3.09
S =0.23X+ 1.35
X =0.82C+ 1.36
4-Chloro-3-Methylphenol
(9.0 - 667.0)
SR = 0.23X + 0.75
S =0.29X+ 1.31
X =0.84C + 0.35
SR = 0.18X+ 1.49
S =0.27X^1.33
X =0.77C + 0.67
SR = 0.18X+0.30
S =0.28X^1.28
X = 0.81 C- 0.03
SR = 0.14X+ 1.31
S =0.27X+ 1.46
X =0.76C + 0.95
4-Nitrophenol
(21.6 - 800.0)
SR=0.38X+2.57
S =0.44X+3.24
X =0.610-1.22
SR=0.28X+2.44
S =0.44X+2.09
X =0.560-2.16
SR = 0.3JX-0.33
S =0.43X+2.90
X =0.580 + 0.74
SR=0.43X-2.96
S =0.39X+5.09
X =0.520+7.02
Table 2. Revised Regression Equations for Accuracy and Precision
Water Type
Applicable Cone. Range -ug/L
Distilled Water
Single-Analyst Precision
Overall Precision
Accuracy
Tap Water
Single-Analyst Precision
Overall Precision
Accuracy
Surface Water
Single-Analyst Precision
Overall Precision
Accuracy
Industrial Effluent
Single-Analyst Precision
Overall Precision
Accuracy
X = Mean Recovery
C = Prepared Concentration
2-Methyl-4, 6-Dinitrophenol
1144 - 1067)
SR = 0.05X + 42.29
S =0.26X+ 23.10
X = 1.04C - 28.04
SR = 0.15X+0.38
S = 0.31 X+ 23.39
X =1.000-29.72
SR = 0.11X^0.66
S =0.35X+ 21.03
X = 1.07C - 13. 19
SR = 0. 15X - 26.29
S =0.42X-2.86
X =0.96C + 0.41
2.4-Dinitrophenol
(90 - 2666)
SR = 0.38X + 2.36
S =0.42X^26.29
X = 0.81 C- 18.04
SR= 0.33X^6.20
S =0.48X^-13.02
X =0.820-24.25
SR=0.28X+ 1.15
S =0.29X^26.97
X =-0.870 + 8.09
SR = 0.25X + 6.43
S =0.36X+ 22.11
X =0.680+7.82
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of 21%. One-half of the RSD-SAs for the
acid compounds are between 17% and
30%. In 95% of the cases, the RSD-SAs
are less than 43%.
The effect of water type was different
for the various base/neutral and acid
compounds. For most compounds, the
water matrix does not have a great effect
on either the accuracy or precision.
Overall, recoveries for the base/neutral
compounds averaged 81% in distilled
water, 74% in tap water, 71% in surface
water, and 69% in the industrial effluent
matrix. Recoveries for the acid compounds
averaged 77% in distilled water, 71% in
tap water, 77% in surface water, and
72% in the industrial effluent. Precision
(RSD and RSD-SA) for the base/neutral
compounds tended to be poorer for the
surface water and industrial effluent
(median RSD = 38% and median RSD-SA
= 28%) than the distilled and tap water
(median RSD = 32% and median RSD-SA
= 22%). Precision for the acid compounds
tended to be poorer for the tap water
(median RSD = 41 % and median RSD-SA
= 25%) than for the distilled water,
surface water and industrial effluent
(median RSD = 32% and median RSD-SA
= 19%).
Conclusions and
Recommendations
It is highly recommended that the
column be checked for resolution of
compounds, peak geometry (tailing), and
total response of the compound. An
improperly performing column can lead
to problems of misidentification and
poor accuracy and precision of the
reported values. Suggested compounds
for checking the column include: 1,3-
dichlorobenzene (7.4 min) and 1,4-
dichlorobenzene (7.8 min) for the early
eluters, acenaphthylene (17.4 min) and
acenaphthene (17.8 min) for the middle
eluters; and chrysene (31.5 min) and di-
n-octylphthalate (32.5 min) for the late
eluting compounds. For the acids, 2,4-
dinitrophenol (15.9 min) and 2-methyl-
4,6-dinitrophenol (16.2 min) are suggested.
Excessive tailing may be minimized by
coating contact surfaces with phosphoric
acid or a weak organic acid.
Some laboratories reported problems
with nonlinearity and poor response with
the following compounds: nitrophenols,
pentachlorophenol, aldrin, DDT, ODD,
DDE and BHC isomers. It is recommended
that the analyst should prepare one of the
standards used for the standard curve
close in response to the sample response.
I It is recommended that the retention
times be checked, especially for the
highly polar compounds, by frequent use
of standards.
Multiple internal standards, such as
deuterated naphthalene, phenanthene,
and chrysene, were recommended by
several of the participating laboratories.
It is recommended that a pure DDT
standard be used to detect possible
degradation of DDT to ODD or DDE.
It is suspected that the low molecular
weight phthalate esters may hydrolyze
under basic conditions used in the
extraction procedure. It is recommended
that this step be performed as quickly as
possible.
This Project Summary was prepared by staff of Radian Corporation, Austin. TX
78766.
Raymond Wesselman and Robert L. Graves are the EPA Project Officers (see
below).
The complete report, entitled "EPA Method Study 30. Method 625—Base/
Neutrals. Acids and Pesticides." (Order No. PB 84-206 572: Cost: $34.00.
subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA22161
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
*USGPO: 1984-759-102-10633
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