Confirmation of N-Nitrosodimethylamine and N-Nitrosopyrrolidine in Foods By Conversion to their Nitramines with Pentafluoroperoxybenzoic Acid

1984 ◽  
Vol 67 (4) ◽  
pp. 751-756
Author(s):  
Walter I Kimoto ◽  
Leonard S Silbert ◽  
Walter Fiddler
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Thermal Energy ◽  
Milk Powder ◽  
Energy Analyzer ◽  
Detection Level ◽  
Electron Capture Detectors

Abstract Amethod is presented, wherein concentrated dichloromethane extracts from malt, beer, and nonfat dried milk powder containing N-nitrosodimethylamine (NDMA), and fried dry-cured and pump-cured bacon containing NDMA and iV-nitrosopyrrolidine (NPYR) undergo 3N HC104- Celite microcolumn cleanup followed by peroxidation with pentafluoroperoxybenzoic acid, a stable solid peroxyacid, to N-nitrodimethylamine and N-nitropyrroIidine, as an aid to nitrosamine confirmation. The nitramine-containing solution underwent further cleanup with 6N HC104-Celite and acid alumina-6 % H2O microcolumns for subsequent analysis by gas chromatography interfaced with thermal energy analyzer and 63Ni electron capture detectors. With a 20 g sample, 1 ppb NDMA and 2.5 ppb NPYR could be confirmed by this method. The extract can be concentrated further before analysis, so the detection level can be reduced to <1 ppb NDMA and 1 ppb NPYR.

Determination of /V-Nitrosodipropylamine in Trifluralin Emulsifiable Concentrates Using Minicolumn Cleanup and Gas Chromatography with Thermal Energy Analyzer

1988 ◽  
Vol 71 (2) ◽  
pp. 333-336
Author(s):  
Dave Wotherspoon ◽  
Ralph Hindle
Keyword(s):  
Gas Chromatography ◽  
Thermal Energy ◽  
Internal Standard ◽  
Energy Analyzer ◽  
Quick Method ◽  
Coefficients Of Variation ◽  
Significant Difference ◽  
Artifact Formation ◽  
And Control

Abstract A quick method for determining /V-nitrosodipropylamine (NDPA) levels in trifluralin emulsifiable concentrate formulations is described. At least 18 samples can be analyzed at one time in a minimum of fumehood space, with up to 90% savings on solvents and materials. A sample aliquot is mixed with a solution containing nitrosamine recovery standards, and nitrosamines are separated by minicolumn cleanup. Internal standard is added directly to the eluate containing the nitrosamines, and levels are determined by gas chromatography with thermal energy analyzer. Recoveries of spiked nitrosamines ranged from 98 to 102%. Coefficients of variation for samples containing 0.5 ppm NDPA are 13%. Minimum detectable limit, calculated as 3 times the noise, is 0.06 ppm. Comparison with the method formerly used by this laboratory shows no significant difference in the analytical results at 95% confidence limits, and control experiments were performed to ensure that there was no artifact formation of NDPA.

scholarly journals Determination of Malathion, Coumaphos, and Fluvalinate Residues in Honey by Gas Chromatography with Nitrogen–Phosphorus or Electron Capture Detectors

2000 ◽  
Vol 83 (1) ◽  
pp. 178-182 ◽  
Author(s):  
Urania Menkissoglu-Spiroudi ◽  
Grigorios C Diamantidis ◽  
Vassiliki E Georgiou ◽  
Andreas T Thrasyvoulou
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
High Selectivity ◽  
Order Model ◽  
First Order ◽  
Quantitation Limit ◽  
Coefficients Of Variation ◽  
Electron Capture Detectors ◽  
Nitrogen Phosphorus

Abstract A rapid, reliable, and inexpensive extraction method was developed to determine acaricide residues in honey by gas chromatography (GC) with nitrogen–phosphorus (NP) or electron capture (EC) detectors. Because of the high selectivity of the NP detector, no interfering peaks were present and no cleanup was necessary. A simple cleanup step is proposed for the GC–ECD analysis. Recoveries from spiked honey samples ranged from 79 to 94.4%, with coefficients of variation of 0.3–18.5%. The quantitation limit obtained was 0.015 mg/kg for malathion, 0.020 mg/kg for coumaphos, and 0.005 mg/kg for fluvalinate. The method was used to determine the disappearance of malathion and coumaphos residues from honey samples collected from beehives treated with these acaricides. The disappearance of both acaricides was rapid and followed a first-order model for the duration of the experiment.

Determination of Nitrate in Dried Foods by Gas Chromatography-Thermal Energy Analyzer

1985 ◽  
Vol 68 (1) ◽  
pp. 41-43
Author(s):  
Holly D Ross ◽  
Joseph H Hotchkiss
Keyword(s):  
Gas Chromatography ◽  
Ethyl Acetate ◽  
Thermal Energy ◽  
Energy Analyzer ◽  
Gas Chromatograph ◽  
Coefficients Of Variation ◽  
Dry Milk ◽  
Nonfat Dry Milk ◽  
Dried Foods

Abstract The method described for determining N03~ in dried foods is based on extraction of N03~ from the sample with subsequent nitration of benzene. The nitrobenzene is extracted with ethyl acetate, analyzed by using a gas chromatograph-thermal energy analyzer (GC-TEA), and quantitated against a nitrobenzene standard. Sensitivity is 100-200 μg/ kg. Coefficients of variation for analyses of dried foods were 3-13%. Recovery of N03" from nonfat dry milk spiked at 10 mg/kg averaged 100%.

Herbicidal Carbamates: Extraction, Cleanup, and Gas Chromatographic Determination by Thermionic, Electron Capture, and Flame Photometric Detectors

1971 ◽  
Vol 54 (6) ◽  
pp. 1366-1370 ◽  
Author(s):  
John H Onley ◽  
George Yip
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Chromatographic Determination ◽  
Food Crops ◽  
Water Mixture ◽  
Flame Photometric Detector ◽  
Photometric Detector ◽  
Electron Capture Detectors ◽  
Cellulose Column

Abstract Extraction, cleanup, and gas chromatographic procedures have been developed for the determination of carbamate herbicides in food crops. Each sample is extracted with ethanol or an ethanol-water mixture and then cleaned up on a MgO-cellulose column. Determinations are made by gas chromatography, using thermionic and electron capture detectors; a flame photometric detector may also be used to quantitate and confirm those carbamates containing sulfur. Recoveries from apples, potatoes, alfalfa, corn, and soybeans at fortification levels of 0.01 to 10 ppm exceeded 80%.

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