Three extraction methods, ultrasonic assisted extraction (USE), microwave assisted extraction (MSE), and conventional single extraction (CSE), in conjunction with the modified three-stage BCR sequential extraction procedure (SEP) were applied to examine the contents of Cd, Cu, Cr, Ni, Pb and Zn from lake sediment samples, to know whether these techniques can reduce extraction time and improve reproducibility. The SEP and developed alternative single extrac- tion methods were validated by the analysis of certified reference material BCR 601. By the use of optimized sonication and microwave conditions, steps 1, 2 and 3 of the BCR sequential extraction methods (excluding the hydrogen peroxide digestion in step 3, which was not performed with sonication and microwave) could be completed in 15-30 min and 60- 150 s, respectively. The recoveries of total extractable metal contents in BCR 601, obtained by three single extractions ranged from 93.3%-102%, 88.9%-104% and 81.2%-96.2% for CSE, USE and MSE, respectively. The precision of the single extraction methods was found in the range of 3.7%-9.4% for all metals (n = 6).
展开▼
