Modified Method for Electron Capture Gas-Liquid Chromatographic Determination of Hexestrol Residues in Bovine Tissues

1978 ◽  
Vol 61 (5) ◽  
pp. 1054-1057
Author(s):  
Hisaya Tobioka ◽  
Ryoji Kawashima
Keyword(s):  
Electron Capture ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Purification Step ◽  
Packing Materials ◽  
Modified Method ◽  
Extraction And Purification ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic (GLC) method with electron capture detection was developed for determining hexestrol residues based on a GLC method for diethylstilbestrol residues. The extraction and purification procedures were based on a published procedure. Pentafluoropropionic (PFP) and heptafluorobutyric (HFB) anhydrides and other halogenated compounds were compared as acylation reagents. PFP anhydride was selected because it provided reproducible GLC responses. Of the 3 column packing materials tested, OV-17, OV-210, and QF-1, OV-17 was the most stable under the GLC conditions used. A pH 10.5—10.6 in the purification step gave higher recoveries than pH 10.3 or pH 10.8 and was selected for use. The method is suitable for determining residues of 0.5 ppb. The limit of sensitivity ranges from 0.1 to 0.2 ppb.

Modified Method for Electron Capture Gas-Liquid Chromatographic Determination of Diethylstilbestrol Residues in Urine of Fattened Bulls

1983 ◽  
Vol 66 (5) ◽  
pp. 1230-1233
Author(s):  
Athanasios E Tirpenou ◽  
Stylianos D Kilikidis ◽  
Athanasios P Kamarianos
Keyword(s):  
Sodium Hydroxide ◽  
Electron Capture ◽  
Silica Gel ◽  
Chromatographic Determination ◽  
Trifluoroacetic Anhydride ◽  
Phenolic Fraction ◽  
Modified Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic (GLC) method with electron capture (EC) detection was developed fof determining diethylstilbestrol residues in the urine of fattened bulls. Diethylstilbestrol (DES) is extracted into benzene, and then into IN sodium hydroxide. The pH of the phenolic fraction (alkaline phase) is adjusted to 10.2 and DES is extracted again into benzene. Sample extracts are cleaned up on silica gel. Trifluoroacetic anhydride (TFAA) is used as acylation reagent, and the derivatized sample is chromatographed on a 3% OV-17 column and measured with a 63Ni EC detector. The method is suitable for determining residues at levels as low as 2 ppb.

Simultaneous Gas-Liquid Chromatographic Determination of Four Sulfonamides in Feeds

1971 ◽  
Vol 54 (6) ◽  
pp. 1277-1282 ◽  
Author(s):  
Robert J Daun
Keyword(s):  
Liquid Chromatography ◽  
Electron Capture ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Gas Liquid Chromatography ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A procedure is described for the gas-liquid chromatographic determination of sulfathiazole, sulfamerazine, sulfamethazine, and sulfaquinoxaline in finished feeds at levels from 0.002 to 0.05%. The procedure utilizes a double derivatization technique to modify the sulfonamides so that they can be determined by gas-liquid chromatography with electron capture detection. The conditions for extraction, derivatization, and gas-liquid chromatography are given, along with recovery data.

Gas-Liquid Chromatographic Determination of Technical Chlordane Residues in Food Crops: Interpretation of Analytical Data

1975 ◽  
Vol 58 (5) ◽  
pp. 1051-1061
Author(s):  
William P Cochrane ◽  
James F Lawrence ◽  
Young W Lee ◽  
Ronald B Maybury ◽  
Brian P Wilson
Keyword(s):  
Field Experiments ◽  
Stationary Phases ◽  
Analytical Data ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Food Crops ◽  
Liquid Chromatographic Determination ◽  
Consistent Method ◽  
Liquid Chromatographic

Abstract An interlaboratory investigation of technical chlordane residues in food crops was carried out to determine the most practical and consistent method of reporting results. Using a technical chlordane reference standard, 8 gas chromatographic stationary phases were studied for their resolution capabilities. The best separations were obtained with SE-30 and its OV-1 equivalent. Using these columns and electron capture detection, potatoes and carrots from supervised field experiments were analyzed in duplicate and quantitated by using 4 methods of calculation. The data were statistically treated to determine the precision and bias for each method. Also, 1 sample was analyzed in duplicate on 2 different occasions by 6 laboratories to substantiate the initial conclusions. Based on the criterion of high precision it is suggested that a comparison of total area under the chromatogram of the sample with total area of a standard technical chlordane be the method of quantitation. Only peaks which are common to both standard and sample have any significance in this type of calculation.

Gas-Liquid Chromatographic Determination of Total Inorganic Iodine in Milk

1977 ◽  
Vol 60 (6) ◽  
pp. 1307-1309 ◽  
Author(s):  
Hendrik J Bakker
Keyword(s):  
Liquid Chromatography ◽  
Iodine Content ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Gas Liquid Chromatography ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Inorganic Iodine ◽  
Liquid Chromatographic

Abstract Total inorganic iodine in milk is determined by conversion to iodobutanone, which is quantitated by gas-liquid chromatography and electron capture detection. As little as 10 μg/L can be determined. The thyroid-active iodine content of milk can be determined rapidly with a relative standard deviation of 1.9%. Average recoveries for added iodide and iodine were 95.5 and 94.6%, respectively.

Gas-Liquid Chromatographic Determination of Permethrin in Bovine Tissues

1979 ◽  
Vol 62 (6) ◽  
pp. 1309-1311
Author(s):  
Delbert D Oehler
Keyword(s):  
Liquid Chromatography ◽  
Electron Capture ◽  
Chromatographic Determination ◽  
Chromatographic Column ◽  
Gas Liquid Chromatography ◽  
Florisil Column ◽  
Bonded Phase ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A method is presented for the determination of permethrin (m-phenoxybenzyl cis,trans-(±)-3-(2,2-dichlorovinyl) - 2,2 - dimethylcyclopropanecarboxylate) in bovine tissues. Fat and muscle samples were cleaned up first by liquid-liquid partition on a bonded phase chromatographic column. Final cleanup of fat and muscle was performed on a short Florisil column. Liver, kidney, spleen, and heart tissues only required cleanup on a Florisil column before quantitation of permethrin by electron capture gas-liquid chromatography.

Gas-Liquid Chromatographic Determination of 3,6-Dichloropicolinic Acid in Soils

1976 ◽  
Vol 59 (2) ◽  
pp. 264-268
Author(s):  
Andrew J Pik ◽  
Gordon W Hodgson
Keyword(s):  
Electron Capture ◽  
Chromatographic Determination ◽  
Soil Samples ◽  
Percentage Recovery ◽  
Detectable Limit ◽  
Minimum Detectable Limit ◽  
Liquid Chromatographic Determination ◽  
Standard Deviations ◽  
Liquid Chromatographic

Abstract A gas-liquid chromatographic (GLC) method has been developed for the determination of the experimental herbicide 3,6-dichloropicolinic acid (Dowco 290) in soils. The method involves extraction of 1 g soil samples with 1N NaCl at approximately pH 7, methylation with diazomethane utilizing a microgenerator, and detection by electron capture GLC. Interferences are small, so that a cleanup step is not necessary even at the 6 ppb level. The procedure is rapid, requiring only 45 min/sample. Recoveries range from 84 to 94% at the 6–1000 ppb level with a minimum detectable limit of 6 ppb. Standard deviations for the percentage recovery values vary from 10.9 to 2.3 for the tested range of 6.7–670 ppb, respectively.

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