Gas Chromatographic Determination of Trace Amounts of the Insect Chemosterilants Tepa, Metepa, Methiotepa, Hempa, and Apholate and the Analysis of Tepa in Insect Tissue

1966 ◽  
Vol 49 (5) ◽  
pp. 1046-1052
Author(s):  
Malcolm C Bowman ◽  
Morton Beroza

Abstract A gas chromatographic method, sensitive to as little as 0.1 nanogram, was devised for analysis of the insect chemosterilants tepa, metepa, methiotepa, hempa, and apholate. The method is needed to monitor amounts and persistence of chemosterilant in treated insects. The procedure uses a flame-photometric detector. Response is linear (phosphorus analysis) between 0.1 and at least 200 ng. The procedure was shown to be directly applicable to analysis of methanol extracts of insects fed tepa. Concurrent gas chromatographic and radiometric analyses indicated that the radiometric method would not give satisfactory results without a suitable cleanup, whereas virtually no cleanup was required for the gas chromatographic analysis. The gas chromatographic method is rapid and easily carried out.

1970 ◽  
Vol 53 (3) ◽  
pp. 566-568
Author(s):  
J E Paterson

Abstract A gas chromatographic method is described for the quantitative determination of dioxathion and chlorfenvinphos in emulsifiable concentrates and livestock dips. A convenient quantity of the emulsifiable formulation is dissolved in xylene and the aqueous dip is extracted with xylene for gas chromatographic analysis, using a mixed silicone oil stationary phase and a flame ionization detector. The coefficients of variation for the dioxathion and chlorfenvinphos determinations in the emulsifiable concentrate are 2.4 and 1.0%, respectively. Recoveries of the former from a fouled dip ranged from 97 to 103% and recoveries of the latter ranged from 92 to 97%.


1987 ◽  
Vol 70 (5) ◽  
pp. 870-874
Author(s):  
Rachel S Greenberg

Abstract A gas chromatographic method is described for determining residues of mecarbam and 3 of its metabolites, mecarboxon, diethoate, and diethoxon, in cottonseeds. For mecarbam analysis, following Soxhlet extraction with chloroform (after blending), the oily extract is partitioned with propylene carbonate and cleaned up on a silica gel column. Metabolites are extracted by the same method, followed by cleanup of mecarboxon on a silica gel column or diethoxon on an alumina column; cleanup of diethoate can be performed on either column. AH 4 compounds are determined using a flame photometric detector equipped with a phosphorus filter. Average recoveries for cottonseed samples fortified with 0.03-1.0 ppm mecarbam ranged from 80 to 88%. Average recoveries were 81-88% for mecarboxon and 90-92% for diethoate (alumina column) and diethoxon from samples fortified with 0.05-1.0 ppm. Average recovery of diethoate from samples cleaned up on the silica gel column were 84-88% in the range of 0.05-0.2 ppm. Values obtained for mecarbam residues in field-treated samples are also presented.


1971 ◽  
Vol 54 (3) ◽  
pp. 711-712
Author(s):  
Martha Fuzesi

Abstract A gas chromatographic method is described for the quantitative determination of N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-tolindine and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyI-p-toluidine herbicides in formulations. The sample is extracted with benzene, and equal amounts of sample and reference solution in the same concentration range are analyzed by gas chromatography, using an electron capture detector and an SE-30/Diatoport S column. The method has been applied successfully to laboratory-prepared and commercial samples.


1996 ◽  
Vol 79 (2) ◽  
pp. 587-588 ◽  
Author(s):  
Lan Zhao ◽  
De-Fang Fan

Abstract A gas chromatographic method is described for determination of chlorothalonil residues in leaves and roots of Scrophularia and in soil. Samples were extracted with acetone and cleaned up on a Florisil column. Chlorothalonil residues are chromatographed directly on a glass column of 1.5% OV-17 and 2% QF-1 coated on 80-100 mesh Chromosorb W (HP) support and measured with a 63Ni electron capture detector. Detection limits are 0.001 ppm for leaf, 0.005 ppm for root, and 0.001 ppm for soil.


1987 ◽  
Vol 70 (4) ◽  
pp. 745-748
Author(s):  
Uaz Ahmad

Abstract A capillary column gas chromatographic method is described for determining parts-per-trillion (ppt) levels of chlorsulfuron in agricultural runoff water. The water sample is acidified with acetic acid and extracted with methylene chloride. The chlorsulfuron in the extract is derivatized to its monomethyl derivative. After Florisil column cleanup, the methylated chlorsulfuron is determined by electron-capture gas chromatography. Recovery of chlorsulfuron from fortified water samples is greater than 80%. Detection limit of the method is 25 ng chlorsulfuron/L water (25 ppt). There are 2 reaction sites on the chlorsulfuron molecule, both of which are susceptible to methylation leading to monomethyl chlorsulfuron and dimethyl chlorsulfuron. A procedure is described to methylate selectively the sulfonamide nitrogen of chlorsulfuron.


1986 ◽  
Vol 69 (4) ◽  
pp. 612-613
Author(s):  
Ramesh T Sane ◽  
Vipul J Doshi ◽  
Sanjay K Joshi ◽  
Vijay K Shastri ◽  
Dhananjay S Sapre ◽  
...  

Abstract A simple gas chromatographic method is described for the determination of histapyrrodine HC1 in marketed formulations. Chlorpheniramine maleate is used as the internal standard. The amount of histapyrrodine HC1 found by the proposed method averaged 19.91 mg/tablet, compared with the label claim of 20 mg/tablet. The method was statistically evaluated for accuracy and precision.


1996 ◽  
Vol 79 (6) ◽  
pp. 1459-1462
Author(s):  
Bernard DeWitt ◽  
Gunnar Finne

Abstract Because of interference by coeluting capsaicinoids, the commonly used liquid chromatographic method for determining butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) in pepperoni and spice blends is not reliable. A gas chromatographic method is described that cleanly separates these antioxidants from interfering substances. Average recoveries of BHA and BHT from oleoresin spiked at 5 concentrations were 97.6 and 104.3%, respectively. From pepperoni spiked at 4 levels, average recoveries were 79.1 and 87.9%, respectively. The repeatability of the method when applied to 5 replicates of pepperoni toppings was 36.4 ± 1.1 ppm for BHA and 32.2 ± 0.8 ppm for BHT.


1997 ◽  
Vol 80 (4) ◽  
pp. 867-870 ◽  
Author(s):  
Paolo Cabras ◽  
Alberto Angioni ◽  
Vincenzo L Garau ◽  
Elizabeth V Minelli

Abstract A rapid and simple gas chromatographic method for determinating cyprodinil, fludioxonil, pyrimethanil, and tebuconazole in grapes, must, and wine is described. An on-line microextraction method was used with a one-step extraction–partition procedure. Nitrogen–phosphorus and mass spectrometric detectors were used, because of their low sensitivity and high selectivity. Because of high selectivity of detector, no cleanup was necessary and the extract was concentrated 5 times. Recoveries from fortified grapes, must, and wine ranged from 93 to 110%. Limits of determination were 0.05 mg/kg for cyprodinil and pyrimethanil and 0.10 mg/kg for fludioxonil and tebuconazole.


1976 ◽  
Vol 22 (6) ◽  
pp. 772-776 ◽  
Author(s):  
S A Harding ◽  
G F Johnson ◽  
H M Solomon

Abstract We describe a sensitive and precise gas-chromatographic method, in which cytosine is used as the internal standard, for determination of an antifungal agent, 5-fluorocytosine, in serum. The trimethylsilyl derivative of this drug is well separated from the internal standard and from normal serum constituents. Amphotericin B does not interfere with the determination of 5-fluorocytosine. The lower limit of detection for 5-fluorocytosine is 1 mg/liter when 200 mul of serum is analyzed. Within-run precision (CV), established by analysis of 10 replicates, was 4.5% at a concentration of 19.9 mg/liter. Twenty-five serum samples were analyzed for 5-fluorocytosine by a microbiological assay and by the gas-chromatographic method. Mean value observed with the bioassay was 78.5 mg/liter and with our procedure was 69.4 mg/liter. When values for our assay were regressed against values for the bioassay, slope of the least-squares line was 0.85, intercept was 2.7 mg/liter, and r was 0.93.


1984 ◽  
Vol 67 (1) ◽  
pp. 192-193 ◽  
Author(s):  
Anthony J Cutaia

Abstract The American Society of Brewing Chemists collaboratively tested a gas chromatographic method for determination of ethanol in beer. Ten laboratories collaborated in a comparison of the ASBC reference method for alcohol by distillation with the GC method. The latter was shown to be at least as precise as the former, it is more rapid, and it can be used for in-line or process monitoring. The method has been adopted official first action.


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