J. Deboer et al., DETERMINATION OF CHLOROBIPHENYLS IN CLEANED-UP SEAL BLUBBER AND MARINE SEDIMENT EXTRACTS - INTERLABORATORY STUDY, Journal of AOAC International, 77(6), 1994, pp. 1411-1422
An interlaboratory study on the determination of individual chlorobiph
enyl congeners (CBs) in cleaned-up seal blubber and marine sediment ex
tracts was organized by the International Council for Exploration of t
he Sea, the Intergovernmental Oceanographic Commission, and the Oslo a
nd Paris Commissions, as the second part of a stepwise-designed interl
aboratory study on the determination of CBs in marine media. Fifty-eig
ht laboratories from 16 countries participated in this exercise, which
involved the determination of 10 CBs in a standard solution, a cleane
d-up seal blubber extract, and a cleaned-up marine sediment extract. S
uggestions were given for instrument optimization. Standard errors of
1.16-1.17 for the standard solution, 1.20-1.33 for the seal blubber ex
tract, and 1.31-1.56 for the sediment extract were obtained for CBs 52
, 101, 118, 138, 153, and 180 by all laboratories with the exception o
f the laboratories giving consistently outlying results. The results f
or CBs 28, 31, 105, and 156 showed larger standard deviations. The 2 m
ajor difficulties for participants in this exercise were correct prepa
ration of a calibration solution and chromatographic separation. The r
esults of the sediment analysis showed a complete lack of agreement. I
t is recommended that, prior to the organization of the third part of
this study, participants should install gas chromatographic columns wi
th minimum lengths of 50 m and maximum internal diameters of 0.25 mm a
nd should prepare calibration solutions from solids of known purity.