Water Quality Research Journal of Canada

Vol. 42 (1): 11 - 19 (2007). General issue

A Microwave-assisted Extraction Method for the Determination of Synthetic Musks in Sewage Sludge

   M Lewina. Svoboda, Jian-Jun Yang, Patricia Falletta, Hing-Biu Lee

Abstract
An efficient microwave-assisted extraction (MAE) procedure has been optimized for the determination of polycyclic and nitro musks in sewage sludge. A centrifuged sludge cake sample (from 1 to 2.5 g ), mixed with 10 g of anhydrous sodium sulfate in a Teflon cell, was extracted with 30 mL of a 1:1 (v/v) mixture of acetone and hexane for 35 min, including a 15-min ramp with a 20-min hold at a controlled temperature of 110░C. After 30 min of cooling, the extract was evaporated and cleaned up on a silica gel column. A concentrated sample extract was then analyzed by gas chromatography/mass spectrometry (GC/MS) in the electron impact mode for the polycyclic musks and in negative ion chemical ionization mode for the nitro musks. This new method has been validated by comparing it to an established accelerated solvent extraction (ASE) method, with method detection limits ranging from 27 to 41 ng/g for the polycyclic musks, and approximately 4 ng/g for the nitro musks. Recoveries of most compounds in spiked samples ranged from 80 to 105%, although the MAE method produced lower recoveries for the nitro musks than the ASE method in archived sludge samples. The results generated by this MAE method were consistent with those prepared by previously reported techniques such as supercritical fluid extraction.

Keywords
microwave-assisted extraction, MAE, musk, sewage sludge

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