scholarly journals Determination of Total Free and Glucose-Conjugated 3-Phenoxybenzyl Alcohol Residues in Foods by Gas Chromatography with Electron Capture Detection

1996 ◽  
Vol 79 (4) ◽  
pp. 967-971 ◽  
Author(s):  
Richard D Mortimer ◽  
J Brian Shields
Keyword(s):  
Gas Chromatography ◽  
Enzymatic Hydrolysis ◽  
Electron Capture ◽  
Field Trial ◽  
Fruits And Vegetables ◽  
Food Samples ◽  
Electron Capture Detection ◽  
Pyrethroid Insecticides ◽  
Heptafluorobutyric Anhydride

Abstract A method was developed to determine the combined amounts of residual, free 3-phenoxybenzyl alcohol (permethrin alcohol) and its acetone-extractable glucosides in representative fruits and vegetables after application of pyrethroid insecticides such as permethrin or cypermethrin. 3-Phenoxybenzyl glucoside was synthesized and used to spike food samples. Conditions were developed for extraction, enzymatic hydrolysis, derivatization with heptafluorobutyric anhydride, and cleanup prior to detection and quantitation by gas chromatography with electron capture detection. Limits of detection in various foods were ≤0.01 ppm. In addition, 2 sets of field trial samples that were sprayed with permethrin and collected at intervals were also analyzed. In general, the amounts of total permethrin alcohol in foods were small.

Modification of AOAC Multiresidue Method for Determination of Synthetic Pyrethroid Residues in Fruits, Vegetables, and Grains. Part I: Acetonitrile Extraction System and Optimization of Florisil Cleanup and Gas Chromatography

1995 ◽  
Vol 78 (6) ◽  
pp. 1481-1488 ◽  
Author(s):  
Guo-Fang Pang ◽  
Yan-Zhong Chao ◽  
Chun-Lin Fan ◽  
Jin-Jie Zhang ◽  
Xue-Min Li ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Fruits And Vegetables ◽  
Electron Capture Detection ◽  
Synthetic Pyrethroids ◽  
Capillary Gc ◽  
Pyrethroid Insecticides ◽  
Multiresidue Method ◽  
Polished Rice ◽  
The Individual

Abstract We present a multiresidue method for determination of synthetic pyrethroids in fruits, vegetables, and grains. The method is a modification of AOAC Method 970.52. Residues are extracted with acetonitrile (for fruits and vegetables) or acetonitrile–water (2 + 1) (for grains) and then transferred to hexane. Coextractives are removed by acetonitrile partitioning and open-column chromatography with deactivated Florisil. The final extract is analyzed by gas chromatography with electron capture detection (GC–ECD). An HP-17 wide-bore column is used to determine the total isomeric content of each insecticide, and a DB-5 narrow-bore column is used to determine the individual isomeric contents of each insecticide. The method was used to recover 8 pyrethroids (biphenthrin, fenpropathrin, cyhalothrin, permethrin, cypermethrin, fluvalinate, fenvalerate, and deltamethrin) spiked at 0.01–4.0 mg/kg in 20 crops (apple, pear, peach, banana, grape, strawberry, potato, tomato, cucumber, pepper, cabbage, carrot, celery, polished rice, wheat, green gram, buckwheat, sorghum, maize, and barley). Recoveries of the 8 pyrethroid insecticides in 6 crops ranged from 83.8 to 112.8%, with a coefficient of variation (CV) of 2.00 to 12.09% for the narrow- bore capillary GC (n = 6) and from 82.8 to 106.4%, CV = 2.93–12.19%, for the wide-bore capillary GC (n = 6). The minimum detectable levels of 0.004–0.028 mg/kg (for fruits and vegetables) or 0.01–0.08 mg/kg (for grains) for the 8 pyrethroids are easy to detect.

Determination of Residues of Alachlor and Its Metabolite in Corn, Soybeans, and Potatoes as Heptafluorobutyryl-2,6-Diethylaniline

1986 ◽  
Vol 69 (4) ◽  
pp. 591-593
Author(s):  
W Harvey Newsome ◽  
Peter Collins ◽  
David Lewis
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Silicic Acid ◽  
Steam Distillation ◽  
Electron Capture Detection ◽  
Heptafluorobutyric Anhydride

Abstract Alachlor [2-chloro-2'6'-diethyl-N-(methoxymethyl)acetanilide] was determined by hydrolysis to 2,6-diethylaniline with 6N HC1 and quantitation of the heptafluorobutyryl derivative by gas chromatography with electron capture detection. 2,6-Diethylaniline was isolated from the hydrolysate by steam distillation, derivatized with heptafluorobutyric anhydride, and the derivative was purified by chromatography on silicic acid with 60% toluene in hexane as eluant. Recoveries from potatoes, soybeans, and corn spiked at levels from 3 to 26 ppb averaged 81,90, and 96% respectively.

Determination of Captan, Folpet, and Captafol in Fruits and Vegetables, Using Two Multiresidue Methods

1984 ◽  
Vol 67 (5) ◽  
pp. 909-912
Author(s):  
Dalia M Gilvydis ◽  
Stephen M Walters
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Fruits And Vegetables ◽  
Electron Capture Detection ◽  
Florisil Column ◽  
Analytical Behavior

Abstract Two multiresidue methods, the Mills method and the Luke et al. method, are widely used for the determination of pesticides in foods. These methods were evaluated for the determination of the fungicides captan, folpet, and captafol in selected fruits and vegetables. The analytical behavior of standards through these methods was investigated first. Recoveries from apples, strawberries, lettuce, and tomatoes fortified with these compounds at levels of 0.2-5.9 ppm were then obtained. The analytes were quantitated by gas chromatography with electron capture detection, using a column of 5% SP-2401 on 100-120 mesh Supelcoport. Recoveries of captan, folpet, and captafol from fortified crops ranged from 69 to 78, 90 to 93, and 67 to 83%, respectively, by the Mills procedure and from 87 to 102, 81 to 106, and 91 to 109%, respectively, by the Luke et al. method modified to include additional solvent elution of the optional Florisil column.

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