Organophosphorus pesticides metabolites

Shafik TM, Bradway DE, Enos HR, et al. 1973a. Human exposure to organophosphorus pesticides A modified procedure for the gas-liquid chromatographic analysis of alkylphosphate metabolites in urine. J Agr Food Chem 21 625-629. 

Table 3 Alkylphosphates Detectable in Urine as Metabolites of Some Organophosphorus Pesticides...

Barr, Dana B., et al. (2004). Concentrations of dialkyl phosphate metabolites of organophosphorus pesticides in the U.S. population. Environmental Health Perspectives 112(2) 186-200. Greenlee, A. R., T. M. Ellis, and R. L. Berg. (2004). Low-dose agrochemicals and lawn-care pesticides induce developmental toxicity in murine preimplantation embryos. Environmental Health Perspectives 112(6) 703-709. 

In two cases of moderate intoxication from mevinphos, urinary excretion of dimethylphos-phate (a metabolite of mevinphos) was almost complete 50 hours after exposure/ Although a number of other organophosphorus pesticides also yield dimethyl phosphate, the presence of significant amounts of this metabolite in the urine may be useful in estimating the absorption of mevinphos. 

A multiresidue method for analyzing 28 common organophosphorus pesticides and three of their main metabolites (paraoxon-ethyl, paraoxon-methyl, and malaoxon) in a variety of crop samples has been developed (59). The use of LC-DAD techniques allowed identification of both organophosphorus pesticides and metabolites by means of standard and spectral comparisons, respectively. A typical chromatogram for fortified apple extract is shown in Figure 4. 

A Lagana, G D Ascenzo, G Fago, A Marino. Determination of organophosphorus pesticides and metabolites in crops by solid phase extraction followed by liquid chromatography/diode array detection. Chromatographia 46 256-264, 1997. 

Environmental Defence recently released Toxic Nation A Report on Pollution in Canadians (Environmental Defence 2005). Samples were collected from 11 people for the presence of 88 chemicals, including heavy metals, PBDEs, PCBs, perfluorinated chemicals, organochlorine pesticides, organophosphorus-insecticide metabolites, and VOCs. The study objectives included determining whether pollutants were present at measurable concentrations in Canadians, identifying chemicals of concern, and creating public awareness of methods for avoiding exposure. 

The first section of this book describes the application of LC/MS to the analysis of agricultural chemicals and their metabolites. Using LC/MS for residue analysis in agricultural chemistry has become routine in many laboratories. Many pesticides, such as the chlorophenoxy acid and sulfonyl urea herbicides or organophosphorus and methyl carbamate insecticides, are too polar or thermally labile for analysis via GC. The use of LC/MS for the identification of polar pesticide metabolites and conjugates, an area traditionally dominated by radiolabeled compounds, stands out as a particularly dramatic demonstration of the power of this technique. 

Table 9.5 Analytical procedures for the determination of different metabolites of organophosphorus pesticides in urine... 

Takade DY, Reynolds JM, Nelson JH. l-(4-Nitrobenzyl)-3-(4-tolyl)triazene as a derivatizing reagent for the analysis of urinary dialkylphosphate metabolites of organophosphorus pesticides by gas chromatography. J Agric Food Chem 2005 27 746-53. 

McNally and Wheeler [179,180] applied SFE to the analysis of sulfonylurea herbicides and their metabolites in soil-solids. Lopez-Avila et al [181] used SFE to extract a series of organochlorine and organophosphorus pesticides from sand using CO2 and CO2 modified with acetone. 

The organophosphorus pesticides oxydemeton-methyl, trichlorfon, dimethoate, dichlorvos, demeton-j-methyl, fenitrooxon, and fenamiphos (and two metabolites)... 

Human Exposure to Organophosphorus Pesticides. Modified Procedure for the Gas Chromatographic Determination of Alkyl Phosphate Metabolites in Urine... 

Nitrobenzyl)-3-(4-tolyl)tri-azene as a Derivatizing Reagent for the Analysis of Urinary Dialkyl Phosphate Metabolites of Organophosphorus Pesticides by Gas Chromatography J. Agric. Food Chem. 27(4) 746-753 (1979) CA 91 50421n... 

A Cis disk has been used to remove chlorotriazine, atrazine, metabolites, organophosphorus compounds, phenylurea, and carbamate pesticides from seawater prior to analysis by HPLC [392],... 

Reference ranges have been established for arsenic, lead, cadmium, mercury, platinum, nickel in blood and urine pentachlorophenol and metabolites of organophosphorus in serum and urine PCBs, fi-HCH, HCB, DDE in blood organochlorine pesticides (fi-HCH, HCB, total DDT) in human milk... 

Until now, many substances including pesticides, extracts of plants, and microbial metabolites have been bioassayed to find inhibitory activity on AF production. Organophosphorus insecticides with cholinesterase inhibitory activity, such as dichlorvos (116 in Figure 26), can inhibit AF production by inhibiting the esterase... 

Toxicity of organophosphates can be potentiated 15-20-fold in rats and mice by pretreatment with a metabolite of tri-O-cresylphosphate, CBDP (2-0-cresyl)-4H-l,3,2-benzodioxa-phosphorin-2-oxide), which is an irreversible inhibitor of CarbEs. In similar studies, tetraisopropylpyrophosphoramide (iso-OMPA), or mipafox, an organophosphate-irreversible inhibitor of CarbEs, potentiates three-to fivefold the toxicity of several OPs (soman, DFP, and methylparathion) and carbamates (carbofuran, aldicarb, propoxur, and carbaryl). Inhibition of CarbEs by CBDP, iso-OMPA, or mipafox pretreatment, particularly in plasma, liver, heart, brain, and skeletal muscles, is a major contributory factor in the potentiation of toxicity of organophosphates and carbamates. Thus, the toxicity of any drug, pesticide, or other type of agent that is normally detoxified by CarbEs, could be potentiated by pre-exposure to an organophosphorus or other carboxylesterase inhibitor. 

Heudorf, U., Angcrer, J.. and Drexlcr, H. (2004). Current internal exposure to pesticides in children and adolescents in Germany Urinary levels of metabolites of pyrethroid and organophosphorus insecticides. Int. Arch. Environ. Health 77, 67-72,... 

Pesticides such as those in the triazine, phenylyurea, pehoxy acid, acetanilide, carbamate, organophosphorus, and pyridylium classes and their metabolites... 

The purpose of Experiments 3 and 4 is to present methods for the TLC determination of pesticides. Experiment 3 describes procedures for the separation and detection of organochlorine (OCl), organophosphorus or organophosphate (OP), and Ai-methylcarbamate insecticides and metabolites (Sherma and Bloomer, 1977 Sherma et al., 1977, 1978 Sherma, 1978). Experiment 4 describes the quantitative TLC determination of three classes of herbicides after isolation from water by conventional separatory funnel extraction or solid-phase extraction (SPE) (Sherma, 1986c Sherma and Boymel, 1983). 

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