Gas-liquid chromatographic separation of some organophosphate pesticides, their hydrolysis products, and oxons

Abstract

A gas-liquid chromatographic technique has been developed to separate and detect, simultaneously, some organophosphate pesticides, their oxons, and hydrolysis products. Reoplex-400 (polypropylene glycol adipate), a polyester liquid phase, was used to separate the organophosphate systems of Diazinon, Baytex, parathion, and malathion. Two detection systems were used-flame ionization and electron-capture. Isothermal separations at 180°C. are described for individual systems of Diazinon. Baytex, and parathion. Also chromatograms and relative retention times indicate multiple analyses of these three pesticides, their hydrolysis products, malathion, and the oxons of parathion and Diazinon. Data are given under isothermal conditions which indicate the generally greater sensitivity of the electron-capture system except for the hydrolysis products of Diazinon and Baytex. The malathion system was examined with the flame ionization detector by techniques of dual isothermal analysis or programmed temperature.At present, there is an incomplete picture of the persistence l_ and fate of organophosphate pesticides in natural water environments. These pesticides have the potential of causing changes in water quality which may affect human and aquatic life. Their toxicity to fish and wildlife is well known. Breidenbach (1965) has outlined other water quality problems caused by organic pesticides.

The p-value approach to quantitative liquid-liquid extraction of pesticides from water. 1. Organophosphates. Choice of pH and solvent

“…An example of the use of p-value data will be discussed now for a specific experimental situation. The gas chromatographic procedure of Suffet and Faust (1967) was utilized for the hydrolytic studies of Diazinon and Diazoxon. Since IMHP and Diazoxon are incompletely separated by the glc procedure, Diazinon and Diazoxon were simultaneously extracted by hexane and quantitated by the electron capture detector to which both have a greater sensitivity.…”

“…Two gas chromatographs were used, a Research Specialities 600 Series with a flame ionization detector and a Microtek MT-220 with a 10 mCi of6 3Ni electron capture detector. Reoplex-400 gas-liquid chromatographic (glc) columns were utilized (Suffet and Faust, 1967). Diazinon, Diazoxon, IMHP, and MMTP were resolved and were quantitated under these conditions with a 4-ft column.…”

Method to determine fenthion and five oxidative metabolites in fat

“…Since the lipophilic properties of fenthion are well known (Mollhoff, 1971), one would expect greater residues of these compounds in fat than in muscle tissue of treated cattle. Methods for the extraction, separation, and quantitation of fenthion and metabolites from a variety of biological samples are available in Anderson et al (1966), Beroza (1968,1969), and Suffet et al (1967). Bowman and Beroza (1968) were the only ones to develop a method by which all six compounds could be analyzed individually by gas chromatography.…”

Μελέτη Της Υδρόλυσης Και Προσρόφησης Επιλεγμένων Οργανοφωσφορικών Φυτοπροστατευτικών Προϊόντων Σε Υδατικά Και Εδαφικά Συστήματα. Διερεύνηση Της Τοξικότητας Σε Θαλασσίους Φυτοπλαγκτονικούς Οργανισμούς

“…Ο χρόνος ηµίσειας ζωής του fenthion για νερό που προέρχεται από εκβολικά ποτάµια συστήµατα είναι της τάξεως των 4,6 d (Lacorte et al, 1995). phosphate (bayoxon) και 3-methyl-4-methylthiophenol (Suffet et al, 1967).…”

“…µετασχηµατίζουν το parathion της p-nitrophenol, στη συνεχεία της pnitrocatechol και τελικά της NO 2 ιόντα και CO 2 (Siddaramappa et al, 1973;Sudhakar-Barik et al, 1976;Sudhakar-Barik & Sethunathan, 1978;Ferris & Lichtenstein, 1980). Η υδρολυτική διάσπαση του parathion στο έδαφος έχει ως κύριο προϊόν την p-nitrophenol (Sethunathan, 1973b;Suffet et al, 1967;Miles et al, 1979;Camper, 1991;Somasundaram et al, 1991), το aminoparathion Rao & Sethunathan, 1979) και το desethyl-aminoparathion Wahid et al, 1980). Μάλιστα, ο ρυθµός της υδρολυτικής διάσπασης αυξάνεται α) αυξανόµενης της περιεχόµενης οργανικής ουσίας του εδάφους (Sethunathan, 1973b;Rajaram & Sethunathan, 1975), β) µετά από επαναλαµβανόµενες εφαρµογές του φυτοπροστατευτικού προϊόντος (Ferris & Lichtenstein, 1980;Sudhakar-Barik et al, 1979), γ) αυξανόµενης της περιεκτικότητας σε ανόργανα κολλοειδή της αργίλου, καθώς έτσι αυξάνεται η επιφάνεια κατάλυσης (Mingelgrid et al, 1977), και δ) παρουσία θειϊκού σιδήρου (Rao & Sethunathan, 1979 (Tomlin, 1997;Freed et al, 1979).…”