Screening of compost for PAHs and pesticides using static subcritical water extraction

Static subcritical water extraction (SubWE) along with solid phase extracti on (SPE) was used for the analysis of PAHs and pesticides in municipal soli d waste compost. Yields obtained for PAHs in certified reference sediment ( CRM 104) were acceptable. The extraction method was simple, rapid, used sma ll sample sizes, and no sample drying was required. Analysis of samples was performed by GC/MS and HPLC. Recovery of spiked pesticides was greatest at 110 degreesC for 20 min extraction time. The optimum extraction for PAH an alysis was achieved at 150 degreesC for 20 min. Addition of C-18 resin as a n "alternate sorbent" upon cooling increased recovery of PAHs but not of pe sticides, however, it increased the stability of atrazine and propazine at higher temperatures. Analysis of three municipal compost samples from the D ayton, OH (USA) area showed no pesticides above the detection limit, howeve r, PAH totals for I I PAHs were 15.97, 14.42, and 20.79 mug g(-1). The tota ls of six of the seven carcinogenic PAHs, for which remediation goals in th e United States is 4.6 mug g(-1), were determined to be 9.89, 6.77, and 13. 06 mug g(-1) dry weight. The highest PAH totals were obtained from compost containing sewage sludge. (C) 2001 Elsevier Science Ltd. All rights reserve d.