Detection of parathion in plasma by electron capture gas chromatography without prior cleanup

Abstract

A rapid sensitive method was developed for the ternal standard. Levels of parathion ranging from detection of the organophosphate insecticide, paraapproximately 0.1 to 0.3 microgram per milliliter thion (0,O-diethyl 0-p-nitrophenyl-phosphorothioof plasma were measured. Average recovery of ate) in mouse plasma. The insecticide is extracted CI4-parathion added to plasma was 93.4%. This from acidified plasma with n-hexane and quantitamethod may be of value in confirming suspected tively measured by means of electron capture gas cases of exposure to this insecticide. chromatography, with methyl parathion as an in-M any of the organophosphate compounds used as insecticides are thiophosphate derivatives. Since these agents are highly toxic, they are generally found in biological tissues in low concentrations after accidental exposure. Insecticides in the nanogram range are commonly measured by electron capture (Petitjean and Lantz, 1963), thermionic emission (Ford and Beroza, 1967) or flame photometric (Brody and Chaney, 1966) gas chromatography.Jain et al. (1965) extracted and identified 23 pesticides from rat blood using the electron capture detector. The method used by these workers did not involve extensive cleanup procedures as did those of earlier investigators. They extracted the pesticides with ether:acetone (1:l) which was then evaporated to dryness. The residue was taken into hexane which was then analyzed gas chromatographically.This report describes a simple gas chromatographic method for estimating nanogram quantities of the thiophosphate insecticide parathion (0,O-diethyl 0-p-nitrophenyl phosphorothioate) in mouse plasma by the use of a single solvent without prior cleanup. METHOD Apparatus.A Hewlett-Packard model 5750 B gas chromatograph fitted with a 63Ni electron capture detector was used to analyze plasma extracts for parathion. The glass column employed was 4 feet by 0.25-inch I.D. and was packed with 3.8% UCC-W982 on 80 to 100-mesh Diatoport S.Argon to methane (95 to 5) was used as the carrier gas and the flow rate was adjusted t o 85 ml. per minute. Column temperature was 195" C, detector temperature 240" C, and injection port temperature 235" C.Mature male mice of the Swiss-Webster strain weighing 20 t o 25 grams were injected intravenously with parathion at a dose of 4 mg. per kg. of body weight. The parathion was dissolved in 5% aqueous Tween 20 solution which was administered in a volume of 1% of the animal weight. The animals were bled by cervical incision at various time intervals after parathion administration and blood was collected in heparinized tubes. The red cells were sedimented by centrifugation in a Sorvall RC2-B refrigerated centrifuge at 3500 r.p.m. for 10 minutes. One milliliter of plasma was placed in a clear glass vial (1-dram capacity) fitted with a polyethylene stopper, and acidified by adding 0.02 ml. of concentrated HCI. This mixture was extracted by shaking for Procedure. 1190 J. AGR. FOOD CHEM. 20 minutes with 1.5 ml. of n-hexane containing methyl parathion (0.5 ng./2 pl....

Detection of Organophosphate Pesticides in Blood Serum from the Patients Suspected of Acute and Chronic Pesticides Poisonings and Its Clinical Significance

“…Many kinds of methods have been introduced to detect minor amounts of organophos phate pesticides (Jain et al 1965, Kanazawa 1969, Vukovich et al 1969, Kashiwa et al 1971). The present study, however, revealed that gas chromatography with flame thermio nic detector is quite sensitive and suitable for detecting such compounds.…”

Spectrophotometric determination of cyanide, sulfide, and sulfite with mercuric chloranilate

“…ride ion with mercuric chloranilate (2,3). The organic solvent presumably promotes the reaction by lowering the dissociation of mercuric chloride and also lowers the blank by decreasing the solubility of mercuric chloranilate.…”

Rapid method for the determination of some organophosphorus insecticides in a small amount of serum in emergency and occupational toxicology cases

“…To study this problem, serum or plasma concentrations of the insecticides would have to be determined. Several methods have been described in literature for the determination of organophosphorus insecticide levels in blood, e.g., gas chromatography without sample extraction,[ 3 4 ] gas chromatography with sample extraction using an electron capture detector,[ 5 6 ] a halogen phosphorus detector,[ 7 ] and a nitrogen detector. [ 8 ] The use of extraction followed by reversed phase high performance liquid chromatography has also been reported.…”