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

Static subcritical water extraction (SubWE) along with solid phase extraction (SPE) was used for the analysis of PAHs and pesticides in municipal solid waste compost. Yields obtained for PAHs in certified reference sediment (CRM 104) were acceptable. The extraction method was simple, rapid, used small 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°C for 20 min extraction time. The optimum extraction for PAH analysis was achieved at 150°C for 20 min. Addition of C-18 resin as an “alternate sorbent” upon cooling increased recovery of PAHs but not of pesticides, however, it increased the stability of atrazine and propazine at higher temperatures. Analysis of three municipal compost samples from the Dayton, OH (USA) area showed no pesticides above the detection limit, however, PAH totals for 11 PAHs were 15.97, 14.42, and 20.79 μgg−1. The totals of six of the seven carcinogenic PAHs, for which remediation goals in the United States is 4.6 μgg−1, were determined to be 9.89, 6.77, and 13.06 μgg−1 dry weight. The highest PAH totals were obtained from compost containing sewage sludge.