Improved cleanup technique for gas chromatographic-mass spectrometric determination of alkylphenols from iota extract

Abstract

A simple and economical cleanup technique was developed to determine alkylphenols by GC-MS from biological extracts containing relatively high lipids. The lipids were successfully removed from bivalve extracts through a two-step cleanup. The new method is a combination of Florisil adsorption chromatography and silyl derivatization technique. Low and high (non-polar and highly polar) molecular weight lipids were removed from the biota extract with deactivated Florisil column in the first step. And in the second step, middle molecularweight (middle polar) lipids were removed in an activated Florisil column after the alkylphenols were converted to corresponding silyl derivatives with bis(trimethylsilyl)trifluoroacetamide (BSTFA). On the basis of the above results, a simple cleanup kit was developed for convenience. The technique was optimized with reference to the activity of packing materials and polarity of eluting solvents. Only 3 g of Florisil, 25 mL of hexane and 10 mL of dichloromethane were required for one sample. The recoveries of alkylphenols from spiked samples varied from 88 to 103% with a low relative standard deviation (mean value: 5.3%) and the recovery was similar or even higher than other methods currently in use. The technique was successfully applied to mussel samples from Masan Bay, South Korea. Simultaneous measurement of these compounds in water, sediment and biota; the resulting bio-concentration factor and their relationships confirm previously published works, validating the method applied. (c) 2007 Elsevier B.V. All rights reserved.