GLC Determination of Ethopabate in Chicken Tissues by Derivative Formation

1970 ◽  
Vol 53 (3) ◽  
pp. 461-464
Author(s):  
P R Handy ◽  
F J Holzer

Abstract The published method for the determination of ethopabate residues in chicken tissues has been improved by formation of the 2,4- dinitrophenyl derivative of m-phenetidine, which is produced by hydrolysis of ethopabate. The derivative is suitable for gas-liquid chromatography, using an electron affinity detector, and allows a simpler cleanup procedure. The sensitivity of the method is about 0.05 ppm; average recoveries at 0.5 ppm range between 66 and 97% for all tissues.

1974 ◽  
Vol 57 (5) ◽  
pp. 1046-1049
Author(s):  
Richard H Larose

Abstract A method is described which permits the removal of interfering co-extractives from lindane, using high-speed liquid chromatography. Fractions are collected from the liquid chromatograph for further analysis by gas-liquid chromatography. The cleanup procedure takes less than 5 min and recoveries of more than 90% are obtained. The detection limit for water samples is 5 ng/L.


1974 ◽  
Vol 57 (1) ◽  
pp. 182-188 ◽  
Author(s):  
Heinz E Braun

Abstract A method is described for the determination of residual chlorpyriphos (O, O-diethyl 0-3,5,6- trichloro- 2 - pyridyl phosphorothioate) and leptophos (O-(4-bromo-2,5-dichlorophenyl) O-methyl phosphonothioate), and their respective oxygen analogs and hydrolytic metabolites, in field-treated vegetables. Samples are extracted by blending with acetonitrile followed by liquid-liquid partitioning between benzene and aqueous sodium carbonate to separate the parent compounds and oxygen analogs from the hydrolytic metabolites. Both fractions are individually cleaned up on silica gel which also serves to fractionate the parent compounds from their oxygen analogs as the result of oncolumn hydrolysis of the oxygen analogs. Chlorpyriphos and leptophos are determined by flame photometric gas-liquid chromatography (GLC); the residual and derived hydrolysis products are derivatized with trimethylsilyl acetamide and determined by electron capture GLC. Overall recoveries from fortified samples averaged 95% for the parent compounds and 85% for the oxygen analogs and hydrolytic metabolites. Detection limits approximated 0.005 ppm for chlorpyriphos and leptophos, 0.002 ppm for the oxygen analogs, and 0.001 ppm for the hydrolytic metabolites.


1999 ◽  
Vol 82 (4) ◽  
pp. 785-791 ◽  
Author(s):  
Nutan Kaushik ◽  
Swadesh Kumar Handa

Abstract An economical and precise method for spectrophotometric determination of fenpropathrin and fluvalinate pyrethroids is reported. The method involves alkaline hydrolysis of the pyrethroids to release HCN, which is converted to cyanogen bromide to form a colored complex with benzidine-pyridine reagent. This method can be used effectively to determine actual concentrations of these pyrethroids in their formulations. Results are comparable with results obtained by gas-liquid chromatography.


1965 ◽  
Vol 48 (2) ◽  
pp. 374-379
Author(s):  
Abdel Rahman (Ali) El-Refai ◽  
Laura Giuffrida

Abstract A simple, rapid, and sensitive method was required for the determination of Dipterex and DDVP in water and insecticidal formulations. Existing methods were found to he unsatisfactory. This paper describes a rapid method for the gas chromatographic separation and estimation of Dipterex and DDVP in macro and micro amounts. The sodium thermionic detector (STD) was used, and the GLC conditions are described. A general method for extraction of the two compounds from water solutions was developed and applied in studying the rate of hydrolysis of Dipterex and DDVP in river water. A simple procedure has been developed for analysis of formulations of Dipterex and DDVP. Several commercial formulations have been analyzed by this method with a precision of 1–2% obtained under experimental conditions.


1980 ◽  
Vol 63 (5) ◽  
pp. 965-969
Author(s):  
H Michael Stahr ◽  
Walter Hyde ◽  
Michael Gaul

Abstract A method for the determination of free mirex in blood has been developed in which whole blood is extracted with acetone–hexane (9+91), passed through Na2SO4, concentrated, and analyzed by electron capture gas-liquid chromatography (GLC). Results were highest for fresh blood. Recoveries were verified by determining 14C-labeled mirex before and after extraction. Little mirex was detected in the samples after extraction. Hydrolysis of residual blood indicates that a metabolite of mirex is released. The possible metabolite has a CLC retention time and mass spectrum which resemble hydroxy metabolites of mirex.


1971 ◽  
Vol 67 (2) ◽  
pp. 303-315 ◽  
Author(s):  
A. J. Moolenaar ◽  
A. P. van Seters

ABSTRACT The 17-oxosteroids were estimated in the urine of 27 patients with Cushing's syndrome by gas-liquid chromatography (G. L. C.). The values of the various steroid fractions are compared with those of normal subjects, patients with thyrotoxicosis and obese subjects. The effect of the age of the patients on the diagnostic value of the invidual 17-oxosteroids and their ratios is discussed.


1992 ◽  
Author(s):  
Ronald L. Shippee ◽  
Avery A. Johnson ◽  
William G. Cioffi ◽  
James Lasko ◽  
Thomas E. LeVoyer

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