Simple and surprisingly effective one-step extraction-cleanup by Soxflo for DDT and its metabolites from environmental samples

A pilot study found that DDT breakdown at the GC inlet was extensive in extracts from some—but not all—samples with high organic carbon contents. However, DDT losses could be prevented with a one-step extraction-cleanup in the Soxflo instrument with dichloromethane and charcoal. This dry-column procedure took 1 h at room temperature. It was tested on spiked soil and peat samples and validated with certified soil and sediment reference materials. Spike recoveries from freshly spiked samples ranged from 79 to 111% at 20–4000 μg/kg concentrations. Recoveries from the real-world CRMs were 99.7–100.2% of DDT, 89.7–90.4% of DDD and 89.6–107.9% of DDE. It was concluded that charcoal cleanups should be used routinely during surveys for environmental DDX pollution in order to mitigate against unpredictable matrix-enhanced breakdown in the GC.