Separation and Micro Quantitative Determination of Dipterex and DDVP by Gas-Liquid Chromatography

1965 ◽  
Vol 48 (2) ◽  
pp. 374-379
Author(s):  
Abdel Rahman (Ali) El-Refai ◽  
Laura Giuffrida
Keyword(s):  
Liquid Chromatography ◽  
Simple Procedure ◽  
Gas Liquid Chromatography ◽  
Experimental Conditions ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of ◽  
Gas Chromatographic Separation ◽  
Sensitive Method ◽  
General Method

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.

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
Keyword(s):  
Liquid Chromatography ◽  
Electron Affinity ◽  
Gas Liquid Chromatography ◽  
Chicken Tissues ◽  
Cleanup Procedure ◽  
Hydrolysis Of

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.

Gas-Liquid Chromatographic Determination of Residues of Chlorpyriphos and Leptophos, Including their Major Metabolites, in Vegetable Tissue

1974 ◽  
Vol 57 (1) ◽  
pp. 182-188 ◽  
Author(s):  
Heinz E Braun
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Aqueous Sodium ◽  
Hydrolysis Products ◽  
Aqueous Sodium Carbonate ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Hydrolysis Of

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.

scholarly journals Spectrophotometric Determination of Fenpropathrin and Fluvalinate in Their Formulations

1999 ◽  
Vol 82 (4) ◽  
pp. 785-791 ◽  
Author(s):  
Nutan Kaushik ◽  
Swadesh Kumar Handa
Keyword(s):  
Liquid Chromatography ◽  
Spectrophotometric Determination ◽  
Alkaline Hydrolysis ◽  
Cyanogen Bromide ◽  
Gas Liquid Chromatography ◽  
Colored Complex ◽  
Precise Method ◽  
Hydrolysis Of

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.

Determination of Extractable Mirex in Whole Blood

1980 ◽  
Vol 63 (5) ◽  
pp. 965-969
Author(s):  
H Michael Stahr ◽  
Walter Hyde ◽  
Michael Gaul
Keyword(s):  
Liquid Chromatography ◽  
Whole Blood ◽  
Gas Liquid Chromatography ◽  
Fresh Blood ◽  
Before And After ◽  
Residual Blood ◽  
Hydrolysis Of ◽  
Hydroxy Metabolites ◽  
Acetone Hexane

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.

DETERMINATION OF VOLATILE ACID PRODUCTION OF CLOSTRIDIUM BY GAS CHROMATOGRAPHY

1967 ◽  
Vol 13 (8) ◽  
pp. 1033-1040 ◽  
Author(s):  
Vester J. Lewis ◽  
C. Wayne Moss ◽  
Wallis L. Jones
Keyword(s):  
Liquid Chromatography ◽  
Acid Production ◽  
Volatile Fatty Acid ◽  
Volatile Acid ◽  
Gas Liquid Chromatography ◽  
Experimental Conditions ◽  
Fatty Acid Production ◽  
Pure Cultures

Gas–liquid chromatography was used to determine volatile fatty acid production by pure cultures of 15 species of Clostridium. Acetic acid was detected from each of the 39 strains examined, although only in trace amounts from C. bulyricum. Butyric acid was detected in considerable amounts from all organisms except the three strains of C. sporogenes tested. In addition, several species produced one or more of the following acids: valeric, isovaleric, isobutyric, and isocaproic. The technique of gas–liquid chromatography proved to be both reliable and rapid for the characterization of volatile acids produced by the bacteria under the experimental conditions employed.

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