Analysis of 4-nonylphenols, phthalates, and polychlorinated biphenyls in soils and biosolids

When sewage sludge is added to agricultural land, organic chemicals contaminants are also added. The fate of these chemicals, particularly those shown to have oestrogenic potential, has received much research and regulatory interest in recent years. A method was developed for the analysis of 4-nonylphenols, phthalates, and PCB congeners in soils, mesophilic anaerobially digested dewatered (MADD) sewage sludge, and MADD sludge-amended soil. After Soxhlet-extraction, the 4-nonylphenols and phthalates were separated from the PCBs on an isolute cyanopropyl SPE cartridge and analysed by GC-MS directly. The PCBs were acid treated on a Bakerbond PCB-A cartridge, then passed through a gel filtration column of Biobeads SX-3 resin, before GC-MS analysis. The method was successfully validated and then used for routine analysis, where average recoveries of the surrogate standards were 83 ± 17% (4-n-heptylphenol), 96 ± 11% (dimethyl-tere-phthalate), 101 ± 12% (dibenzyl-phthalate), and 79 ± 13% (PCBs 6, 54, 104, 155, and 198).