Cleanup with Two Florisil Columns for Gas Chromatographic Determination of Multiple Pyrethroid Insecticides in Products of Animal Origin

1994 ◽  
Vol 77 (6) ◽  
pp. 1634-1638 ◽  
Author(s):  
Guo-Fang Pang ◽  
Tie-Sheng Zhao ◽  
Yan-Zhong Chao ◽  
Chun-Lin Fan

Abstract A gas chromatographic method was developed for the simultaneous determination of 9 pyrethroid insecticides in products of animal origin. The multiresidues of the pyrethroids in different samples were extracted with acetone–petroleum ether (1+1), and extracts were cleaned up on a Florisil partition column and a Florisil adsorption column. Four animal tissue samples were examined at 0.05–0.25 ppm fortification levels. The average recoveries of all insecticides were 76.9–88.0%, and the coefficients of variation were <4.6% for all insecticides except permethrin. The detection limits of the method were ca 5 ppb for all insecticides but permethrin, which had a detection limit of ca 10 ppb.

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%.


1986 ◽  
Vol 69 (3) ◽  
pp. 488-490
Author(s):  
William R Betker ◽  
◽  
E W Balcer ◽  
O O Bennett ◽  
W R Coffman ◽  
...  

Abstract A collaborative study was conducted on a gas chromatographic method for determination of fensulfothion. Eleven laboratories analyzed 2 technical and two 6 lb/U.S. gal. spray concentrate samples. In the analysis, samples are dissolved in methylene chloride which contains 4-chlorophenyl sulfoxide as an internal standard, and solutions are injected into a gas chromatograph equipped with an OV-330 column. Withinlaboratory repeatability was 0.79% for technical product and 0.37% for the spray concentrate samples, with coefficients of variation of 0.88 and 0.58%, respectively. Among-laboratories reproducibility was 0.81% for technical product and 0.53% for the spray concentrate, with coefficients of variation of 0.91 and 0.84%, respectively. The method has been adopted official first action.


1987 ◽  
Vol 70 (1) ◽  
pp. 55-57
Author(s):  
Daniel E Terry

Abstract A gas chromatographic method for the determination of isofenphos (OFTANOL®) in isofenphos technical and liquid formulations has been developed and collaboratively studied by 11 laboratories. Two technical samples and 2 liquid flowable samples were analyzed after shaking/extracting in methanol which contained diisobutyl phthalate as an internal standard. The extracts were analyzed by gas chromatography using an SP-2100 column and either flame ionization or thermal conductivity detection. Coefficients of variation were 0.57 and 1.27% for the technical and formulated products, respectively. The GC method has been adopted official first action as a AOACCTPAC method.


1998 ◽  
Vol 81 (6) ◽  
pp. 1185-1189 ◽  
Author(s):  
Paolo Cabras ◽  
Alberto Angion ◽  
Vincenzo L Garau ◽  
Filippo M Pirisi ◽  
Vincenzo Brandolini

Abstract Azoxystrobin, fluazinam, kresoxim-methyl, mepanipyrim, and tetraconazole were determined in grapes, must, and wine by a gas chromatographic method with nitrogen-phosphorus (NP) and mass spectrometric (MS) detectors. Pesticides were isolated from the matrixes by online microextraction with acetone-hexane (50 + 50, v/v). Because of the high selectivity of NP and MS detectors, no interfered peaks were present and no cleanup was necessary. Recoveries from fortified grapes, must, and wine ranged from 80 to 111 %, with coefficients of variation ranging from 1 to 14%. Limits of determination were 0.05 mg/kg for kresoxim-methyl and 0.10 mg/kg for the other compounds.


1985 ◽  
Vol 68 (3) ◽  
pp. 419-421
Author(s):  
George Yip

Abstract Eleven collaborators participated in this study of a gas chromatographic method for the determination of pentachlorophenol (PCP) in gelatin. Following acid hydrolysis of a 2 g sample, PCP is extracted with hexane and partitioned into KOH solution. After reacidification, PCP is again extracted with hexane for determination by electron capture gas chromatography on a 1 % SP-1240DA column. Three duplicate practice samples (0.0, 0.5, and 1.5 ppm) and 5 blind duplicate collaborative samples (0.0, 0.02, 0.1, 0.5, and 2.0 ppm) were analyzed by each collaborator. Mean recoveries of PCP in the collaborative samples ranged from 88% at the 0.02 ppm fortification level to 102% at the 0.1 ppm level; the overall mean recovery was 96%. Interlaboratory coefficients of variation ranged from 16.4% for the 0.1 ppm fortification level to 22.9% for the 0.5 ppm level; the overall interlaboratory coefficient of variation was 19.5%. The method has been adopted official first action.


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.


1984 ◽  
Vol 67 (2) ◽  
pp. 284-289 ◽  
Author(s):  
James A Ault ◽  
Tim E Spurgeon ◽  
◽  
M M Anderson ◽  
R Bowers ◽  
...  

Abstract A gas chromatographic electron capture detector method is described for the quantitative determination of organochlorine pesticide residues in poultry fat. The samples are rendered and cleaned up using automated gel permeation chromatography. The collaborative samples consisted of 10 fortified samples and one incurred residue sample, all in duplicate. Fortification levels ranged from 0.15 to 1.0 ppm for a-BHC, lindane, cis- and frans-chlordane, octachlor epoxide, o,p' and p,p'-DDT, p,p'-DDE, p,p'-TDE, hexachlorobenzene, heptachlor epoxide, dieldrin, endrin, methoxychlor, mirex, and toxaphene. The average recovery was 91.9% with a range of 81-102%. The ranges of coefficients of variation were: CVo = 3.39-14.79%; CVL = 0-16.6%; and CVx = 5.82-19.0%. The results indicate accuracy and precision comparable to other official methodology. The method has been adopted official first action.


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.


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