INTERLABORATORY EVALUATION OF AN OFF-LINE SUPERCRITICAL-FLUID EXTRACTION AND GAS-CHROMATOGRAPHY WITH ATOMIC-EMISSION DETECTION METHOD FOR THE DETERMINATION OF ORGANOTIN COMPOUNDS IN SOIL AND SEDIMENTS
V. Lopezavila et al., INTERLABORATORY EVALUATION OF AN OFF-LINE SUPERCRITICAL-FLUID EXTRACTION AND GAS-CHROMATOGRAPHY WITH ATOMIC-EMISSION DETECTION METHOD FOR THE DETERMINATION OF ORGANOTIN COMPOUNDS IN SOIL AND SEDIMENTS, Journal of chromatography, 785(1-2), 1997, pp. 279-288
Citations number
22
Categorie Soggetti
Chemistry Analytical","Biochemical Research Methods
A collaborative study was Conducted, with eight laboratories participa
ting, to determine the method accuracy and precision of an off-line su
percritical fluid extraction (SFE) method for organotin compounds. Thi
s method involves extraction of organotin compounds from solid matrixe
s with supercritical carbon dioxide, modified with 5% methanol, at 450
atm and 60 degrees C for 20 min in the static mode followed by 30 min
in the dynamic mode. The extracted material was collected in either m
ethylene chloride or on a C-18-bonded silica trap followed by a methyl
ene chloride rinse. The extracted material was derivatized with pentyl
magnesium bromide and analyzed by gas chromatography with atomic emis
sion detection (GC-AED). The study design was based on the AOAC blind-
replicate design with balanced replicates. The study samples consisted
of three solid matrixes that were spiked with organotin compounds at
1000 ng/g (as Sn) and one unspiked matrix that contained dibutyltin an
d tributyltin compounds at independently determined levels. The result
s of this interlaboratory study indicate that the SFE method works sat
isfactorily for the tri- and tetra-substituted organotin compounds but
that the di- and mono-substituted organotin compounds are quite diffi
cult to extract under these conditions. Higher pressures and different
modifiers may be required to enable extraction of the mono- and di-su
bstituted organotin compounds from soils and sediments. (C) 1997 Elsev
ier Science B.V.