United States
                     Environmental Protection
                     Agency
Environmental Monitoring
and Support Laboratory
Cincinnati OH 45268
                     Research and Development
EPA-600/S4-84-078  Nov. 1984
«»EPA          Project  Summary

                     EPA  Method  Study  28,
                     PCBs  in  Oil
                     Susan M. Sonchik and Richard J. Ronan
                       The full report describes the experi-
                     mental design  and the results of the
                     U.S. Environmental Protection Agency
                     (USEPA)  Method  Study  28 for two
                     analytical methods to detect polychlo-
                     rinated biphenyls (PCBs) in oil. In this
                     study,  the  methods were  used to
                     analyze for four PCB Aroclors {1016,
                     1242, 1254, and  1260), 2-chlorobi-
                     phenyl (2-MCB),  and decachlorobi-
                     phenyl  (DCB). The first  method
                     consists of diluting the oil in hexane and
                     analyzing by gas chromatography using
                     an electrolytic conductivity detector in
                     the halogen mode. The second method
                     consists of diluting the oil in hexane,
                     cleaning/separating with sulfuric acid
                     extraction or with column chromatog-
                     raphy, and analyzing by gas chromatog-
                     raphy using an electron capture detec-
                     tor. Four oil types  were tested in this
                     study: capacitor fluid, hydraulic fluid,
                     transformer oil, and waste oil.. Each.oil
                     was spiked with six concentration levels
                     of PCBs that constituted three Youden
                     pairs. Capacitor fluid was spiked with
                     Aroclor 1016, hydraulic flulid with
                     Aroclor 1242 and 2-MCB, transformer
                     oil with Aroclor 1260 and DCB, and
                     waste oil with Aroclor 1254.
                       Statistical analyses and conclusions
                     presented in the full report are based on
                     analytical data   obtained  by  18
                     participating  laboratories   and  two
                     volunteer laboratories.  The two
                     methods are assessed quantitatively
                     with respect to their expected precision
                     and accuracy. In addition, aspects of
                     the methods, such as sample stability
                     and  methods  detection  limits,   are
                     discussed.
                       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 document-
ed in a separate report of the same title
(see  Project  Report  ordering
information at back).

Introduction
  In  1976, polychlorinated biphenyls
(PCBs)  became regulated substances
under the U.S. Toxic Substances Control
Act (TSCA, PL  94-496). In support of
Section 6 (e)(1) of TSCA, Final Rules Pre-
scribing Requirements for Disposal and
Marking of PCBs  in  PCB-Containing
Materials, an interlaboratory study was
conducted for two test procedures for the
analyses of PCBs in oil. The PCBs studied
were  Aroclor  1016,  Aroclor  1242,
Aroclor 1254, Aroclor 1260, 2-MCB and
DCB.
  The interlaboratory study involved the
analyses of four PCB-spiked oil  types by
20  laboratories  and  was  conducted
between September. 1981 and December
1981. The method  evaluated in this study
is described in the USEPA Draft Method
"The  Analysis  of  Polychlorinated
Biphenyls  in  Transformer  Fluid and
Waste Oils" (revised June 1981).

Procedure
  The  study  'was  patterned  after
Youden's   non-replicate  plan  for
collaborative  evaluation of analytical
methods, in which samples are analyzed
in pairs, each member of a pair  having a
slightly different  concentration of  the
constituent of interest.  The analyst is
directed to conduct a single analysis and
to report one value for each sample, as for
a normal routine  sample.  Samples of
three Youden pairs  used in this study
contained low,  medium, and high con-
centrations of the PCBs, 2-MCB, and DCB,
spiked into four different oil types and
then analyzed.

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  Prior  to  the interlaboratory method
study, participants were familiarized with
both the study design and the analytical
procedure through  a preliminary study
involving analyses  of  two oil samples
spiked  at  mid-level  concentrations
following prescribed instructions. After
resolving method interpretation and ana-
lytical problems,  participating  laborato-
ries were supplied with the test materials
required by the formal collaborative study
and instructed to begin the analyses.
  Statistical analyses of the data were
performed   using   the  Interlaboratory
Method Validation Study computer pro-
gram, which was  developed at  Battelle's
Columbus Laboratories for USEPA. The
program is  designed to output the raw
data in tabular form and compile summary
statistics including:
  • Number of data points

  • True value

  • Mean recovery

  • Accuracy as percent relative error

  • Overall standard deviation

  • Overall  percent  relative  standard
    deviation

  • Single-analyst standard deviation

  • Single-analyst percent relative
    standard deviation

  The   overall  standard  deviations
indicate the dispersion expected  among
values  generated from  multiple
laboratories. The single-analyst standard
deviations  indicate  the  dispersion
expected among replicate determinations
within a single  laboratory.
Results and Discussion

  The data collected during this interlab-
oratory study were statistically analyzed
in order to  establish  the relationship
between accuracy and  the true concen-
tration,  and between precision and the
mean recovery. Those  relationships are
summarized  by  the linear regression
equations presented  in Table 1.
  The final  rules under the U.S. Toxic
Substances   Control  Act  prescribe  a
concentration of 50 mg/kg of PCB in oil
for disposal and marking. Therefore, this
value (except for DCB) was substituted
into the respective regression equations
and the accuracy and precision compared
for   the   HECD  and   ECD  methods.
Percentage recoveries for all PCBs/oils
averaged  approximately 84  percent for
both detection systems. The overall and
single-analyst  standard  deviation
approximated   10.0  and 7.0  mg/kg,
respectively, for both detection systems.
  Percentage  recoveries of  DCB  in
transformer oil were unusually high for
the HECD and ECD methods and were
attributed to data submitted from four
laboratories on three of the six ampules.
Subsequent recalculation without  their
data resulted in the following regression
equations:

   HECD X= 1.02C+0.05

   S = 0.39 X + 0.00
   Sr = 0-12 X +0.08

   ECD X = 1.01  C + 0.00

   S = 0.37 X + 0.03
   Sr = 0.06 X + 0.08
                      Conclusions and
                      Recommendations
                        Based  upon   the   results  of  the
                      interlaboratory study for PCBs in oils, it is
                      concluded that:

                        • At a concentration level of 50 mg/kg,
                          the HECD and ECD methods gave
                          comparable results.

                        • Outlier tests  rejected 19 percent of
                          the data from 20 laboratories.

                        • The HECD  and ECD methods in
                          general gave  a pronounced negative
                          bias for recovery.

                        • The minimum detection level for the
                          ECD method is consistently  lower
                          than for the HECD method.

                        Some laboratories  had  difficulty
                      integrating the DCB peak area, especially
                      at  concentrations  approximating  0.4
                      mg/kg. It is recommended that the oven
                      temperature be optimized to provide the
Table 1.    Summary of Accuracy and Precision Regression Equations
Oil/PCB
   X, mg/kg
   S, mg/kg
   Sr, mg/kg
Capacitor Fluid/1016 (33-492 mg/kg)

     HECD        X = 0.86T + 1.21
     ECD          X = 0.81T+3.10

Hydraulic Fluid 1242 (39-492 mg/kg)

     HECD        ~X = 0.89T- 4.28
     ECD          X = 0.92T-5.87

Hydraulic Fluid/2-MCB (41-1O18 mg/kg)

     HECD        ~X = 0.977 - 13.00
     ECD          X = 0.88T -  5.35

Transformer Oil/1260 (32-392 mg/kg)
     HECD
     ECD
X_ = 1.02T - 2.62
X = 1.04T - 4.46
 Transformer Oil/DCB* (0.37-16.6 mg/kg)
     HECD
     ECD
X = 1.63T - 0.20
X = 1.26T - 0.09
 Waste Oil/1254 (46-461 mg/kg)
     HECD
     ECD
X = 0.84T - 2.00
X = 0.95T - 7.02
                     S = 0.23X + 0.90
                     S = 0.35X- 2.70
                     S = 0.12X. + 2.50
                     S = 0.13X + 5.45
                     S = 0.16X + 1.74
                     S = 0.32X + 2.42
S = 0.15X + 5.97
S =
S = 0.74X - 0.14
S = 0.55X- 0.06
S = 0.17X^6.28
S = 0.12X + 3.29
                    Sr. = 0.09X + 4.98
                    Sr = 0.24X- 1.86
                    Sr = 0.08X^ + 3.29
                    Sr = 0.11X- 0.67
                     Sr = 0.13X -0.40
                     Sr = 0.24X + 0.73
Sr = 0.11X +3.50
Sr = 0.04X + 1.89
Sr = 0.12X + 0.08
Sr = 0.39X - 0.07
Sr = 0.09X + 5.59 '
Sr = 0.09X + 2.07
X = Mean Recovery.
S = Overall Method Precision.
Sr = Single-Analyst Method Precision.
T = True Value for the Concentration.
* = See recalculated regression equations in text.

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best peak geometry to assure the best
accuracy and precision for the HECD and
ECD methods.
  AM. SonchikandR. J. Ronan are with Versar, 'inc., Springfield, VA 22151
  Edward L Berg and Robert L. Graves are the EPA Project Officers (see below)
  Incomplete report. entitled"EPA Method Study 28,'PCB's in Oil," (Order No PB
    85-115178; Cost: $8.50, 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
  U.S. GOVERNMENT PRINTING OFFICE; 1984 — 559-016/7849

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