scholarly journals Gas Chromatographic Determination of Cyprodinil, Fludioxonil, Pyrimethanil, and Tebuconazole in Grapes, Must, and Wine

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.

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.


1983 ◽  
Vol 66 (6) ◽  
pp. 1322-1326
Author(s):  
Hing-Biu Lee ◽  
Alfred S Y Chau

Abstract A sensitive gas chromatographic method was developed for the multiresidue determination of 7 neutral herbicides in sediment. The sediment sample was ultrasonically extracted 3 times with acetone. The extract was concentrated to about 50 mL and then partitioned with 2% KHCO3 and CH2C12. The organic phase was dried over anhydrous Na2So4. The concentrated extract was then cleaned up on a 10% deactivated Florisil column, and the herbicides were separated into 2 fractions. Further cleanup of these fractions was performed on activated Florisil columns. Electron capture detection was used for analysis except for atrazine which was analyzed by nitrogen-phosphorus detection. Recoveries of the herbicides from fortified sediment samples at 3 levels were generally better than 80%. The practical detection limit of this method was 1 ppb or 1 ng/g based on a 50 g sediment sample.


1989 ◽  
Vol 72 (4) ◽  
pp. 660-662
Author(s):  
Jia-Lun Wu ◽  
De-Fang Fan

Abstract A gas chromatographic method is described for direct determination of carbetamide residues in rape and soil. Rapeseed, leaves and stem of rape, and soil samples are extracted with acetone and the extracts are cleaned up by coagulation and partition with petroleum ether, followed by extraction with dichloromethane. Carbetamide is determined by gas chromatography using a nitrogen-phosphorus detector. Recovery ranges for rapeseed, leaves and stem of rape, and soil samples fortified with 0.1-10 ppm carbetamide were 91.4-103% [average 97.2 ± 12% (n = 9)], 94.4-102% [98.2 ± 4.4% (n = 12)], 87.9-93.9% [91.2 ± 6.5% (n = 9)1, and 86.7-102% [94.5 ± 4.5% (n = 15)], respectively.


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.


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.


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