River-lettuce

Another groundwater contaminant that can be removed by reduction reactions is perchlorate. Ammonium perchlorate is a solid rocket fuel, and wastes from its manufacturing have contaminated some irrigation and drinking water sources, among them the lower Colorado River in the American Southwest. Elevated perchlorate levels have been linked to human health effects, and because perchlorate has been found in vegetable crops such as lettuce, there is concern that this contamination could have serious consequences. 

Four bioassays a) 120h lettuce germination test (Lactuca sativa) b) 48h acute crustacean test (Ceriodaphnia dubia) c) 96h acute amphipod test (Hyalella azteca) Waters collected from wells dug in an urban landfill, sediments collected in an adjacent river... 

Volmer et al. studied phenylureas and sulfonylureas by TSP-LC-MS after sample concentration by Cjg SPE [175]. 15 phenylurea- and 1 thiourea pesticides besides 112 polar pesticides from other pesticide classes were examined by TSP ionisation, detection limits and TSP mass spectra of these polar compounds were presented [245], Besides other polar pesticides, the phenylurea pesticides isoproturon and diuron were on-line concentrated on a precolumn from several surface and drinking water samples and then determined by TSP-LC-MS [247]. A multi-residue TSP-LC-MS method was published by Moore et al. for the determination of the urea pesticides chlortoluron, diuron, isoproturon, and Unuron in water samples after Cig-SPE [248]. Ci8 Empore disks were applied to concentrate phenylureas from river water and spiked seawater samples prior to TSP-LC-MS. Detection limits of 2-20 (ig L and recoveries between 80 and 125% were observed [239]. TSP-LC-MS (SIM) in the positive mode allowed determination of the urea pesticides chlor-bromuron, diuron, linuron, metobromuron, monuron, neburon in apples, beans, lettuce, peppers, potatoes and tomatoes with detection limits of 0.025-1 ppm [255]. 20 other polar pesticides, linuron, which was under suspicion of being a dietary oncogenic risk (US Natl. Res. Council) was determined by TSP-LC-MS a single rapid procedure in vegetables with detection limits of 0.05-0.10 ppm [270]. TSP-LC-MS and ESI were used in a multi-residue method for determination of the sul-... 

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