Pesticide parathion

D. H. Chunga, Comparative study of three immunoassays based on monoclonal antibodies for detection of the pesticide parathion-methyl in real samples. Anal. Chim. Acta 511, 323-331 (2004). 

A.Y. Kolosova, J.H. Park, S.A. Eremin, S.J. Kang and D.H. Chung, Fluorescence polarization immunoassay based on a monoclonal antibody for the detection of the organophosphorus pesticide parathion-methyl. J. Agric. Food Chem. 51, 1107-1114 (2003). 

Organophosphorus acid pesticides Parathion and methylparathion Insecticide 300-800... 

Many enzymes have been entrapped successfully in sol-gel matrices44,45d h. The entrapment of parathion hydrolase44,51, which is capable of detoxifying and detecting the pesticide Parathion, demonstrates the potential of the sol-gel methodology in environmental applications. 

Switzerland, was 61 ppt. These are very small numbers, and exposure from breathing air containing such low levels of these substances may not be very harmful. Except for one case of polluted water, these two substances have not been found in U.S. public drinking waters. The background levels of these compounds in foods eaten by humans are not known either. Because the chemicals break down rapidly, any exposure from these levels will be small. 4-Nitrophenol has been found in the urine of people who did not have any known exposure to this substance. The 4-nitrophenol found in human urine comes from the breakdown within the body of a pesticide, parathion, that is commonly used on certain agricultural products that many of us eat. 

The major metabolic route for 2-nitrophenol and 4-nitrophenol is conjugation, with the resultant formation of either glucuronide or sulfate conjugates. Conjugates are more polar than the parent compounds and, therefore, are easier to excrete in the urine. Other possible routes of metabolism include reduction to amino compounds or oxidation to dihydric nitrophenols (catechols). In humans, the evidence is indirect and comes from studies of exposure to the pesticide parathion, of which 4-nitrophenol is a metabolite (Fatiadi 1984). 

Biomarkers of Exposure and Effect. Information regarding populations exposed specifically to 2-nitrophenol or 4-nitrophenol is not available. However, data derived from animal studies indicate that unchanged 2-nitrophenol or 4-nitrophenol or the sulfate and/or glucuronide conjugates monitored in the urine represent biomarkers of exposure. The same would probably occur in humans. This assumption is based on studies in populations exposed to the pesticide parathion, of which 4-nitrophenol is a metabolite. Individuals exposed to parathion excreted 4-nitrophenol and conjugates in the urine (Fatiadi 1984). 4-Nitrophenol is also a metabolite of pesticides other than parathion (Fatiadi 1984) and of nitrobenzene (Piotrowski 1967 Robinson et al. 1951b). However, because 2-nitrophenol and 4-nitrophenol and their metabolites are rapidly excreted in the urine, these biomarkers are only valuable in evaluating acute situations, as demonstrated by Arterberry et al. (1961) in humans exposed to parathion. Hence, the development of methods to detect alternative biomarkers, the presence of which in body fluid or tissues can be associated with chronic exposure levels of nitrophenol, would be useful. 

As an example of differences in soil residue persistence between the organophosphates and chlorinated hydrocarbon pesticides, parathion and malathion residues were present at the 0.1 p.p.m. level within 8 days of application whereas aldrin [according to Lichtenstein (23)] when applied at the same concentration, persisted 5 months longer as did aldrin and dieldrin at 40% of the applied dosage. Decker et al. (12) report that aldrin and dieldrin residues in soils never exceeded 13.2% of the total applied when tested one year after the last application. Other workers (24) have reported that on a loamy soil, under existing weather conditions, aldrin and dieldrin residues were present at a level of approximately 20% of the total applied insecticidal dosage over a 5-year period. 

The use of protein-coated acoustic wave devices for detection of gas-phase species has also been reported with claims of good sensitivity and selectivity. Guilbault et al. reported TSM sensors for the reversible gas-phase detection of formaldehyde [227], and organophosphorous pesticides [228,229]. More recent studies have cast some doubt as to whether the gas-phase sensitivity was the result of selective immunochemical binding, or simply due to nonspecific adsorption. In work reported by Thompson et al. [230], sensors coated with parathion antibody exhibited sensitivities to the pesticides parathion, malathion, and disul-foton that were remarkably similar to sensors coated with nonspecific proteins (valproic acid antiserum, human immunoglobulin G, and bovine serum albumin). The fact that the previous study [228] reported significantly larger sensitivity at... 

The stratum comeum, composed of keratinized dead cells that are continually being replaced, is the first major barrier to chemical agents. The barrier qualities of the stratum comeum depend on a number of factors, including its location on the body, which affects thickness, and how much hair is present. Thus, hair follicles and sweat glands can either provide charmels through the stratum comeum, and thereby bypass its barrier attributes, or at least provide increased surface area for penetration of compounds, since a number of compounds were shown to penetrate faster in hair follicle-rich areas (lUel et al, 1991). Maibach studied three radiolabeled pesticides -parathion, malathion, and carbaryl - for their permeability at 13 different anatomical sites in humans (Maibach et al, 1971). Variations in percutaneous penetration were observed higher penetration of the pesticides occurred at the abdomen and dorsum of the hand. 

The Council directive concerning the quality required of surface water intended for the abstraction of drinking-water in the Member States 75/440/EEC of 16 June 1975 lays down mandatory levels of phenols, dissolved or emulsified hydrocarbons, polycyclic aromatic hydrocarbons, total pesticides (parathion, BHC, dieldrin) which the treated waters must reach after application of the appropriate treatment. 

Recently SuflFet (25) and Faust and Suffet (26) reported an intensive study on the separation and identification of the phosphate ester pesticides parathion, diazinon, and fenthion and their degradation products. A summary of a microspectrophotometric ultraviolet technique that was utilized as an aid in identifying these compounds is presented here. 

The main advantage of MS/MS is its abihty to analyse specific target molecules directly from biological matrices without any sample preparation. One important application of MS/MS in food analysis can be the rapid screening of intact fruits or vegetables for the presence of mycotoxins or pesticides. For example intact lettuce leaves can be introduced directly into the ion source and analysed for the presence of the pesticide parathion. The CAD (methane gas) spectrum of this pesticide shows the parent ion at m/z 291 and two daughter ions at m/z 169 and m/z 154. If the peak at m/z 291 of the normal spectrum of the contaminated lettuce leaf is selected and its CAD spectrum is recorded and... 

Misik J, Pavilkova R, Josse D, Cabal J, Kuca K. In vitro skin permeation and decontamination of the organophosphosus pesticide parathion under various physical conditions - evidence for a wash-in effect. Toxicol Mech Methods. 2012 22 520-5. 

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