Determination of Ethyl Carbamate (Urethane) in Alcoholic Beverages Using Capillary Gas Chromatography with Thermal Energy Analyzer Detection: Collaborative Study

1994 ◽  
Vol 77 (1) ◽  
pp. 64-67 ◽  
Author(s):  
Randolph H Dyer
Keyword(s):  
Gas Chromatography ◽  
Thermal Energy ◽  
Capillary Gas Chromatography ◽  
Capillary Column ◽  
Collaborative Study ◽  
Ethyl Carbamate ◽  
Alcoholic Beverages ◽  
Energy Analyzer ◽  
Distilled Spirits

Abstract A gas chromatographic (GC) procedure for the determination of ethyl carbamate (urethane) in distilled spirits and wines using a thermal energy analyzer (TEA) system was collaboratively studied by 5 laboratories. Distilled spirits such as whiskey, brandy, gin, rum, and vodka containing low solids can be injected directly into the GC system without extraction. Liqueurs require extraction. Wine, beer, sake, and similar samples containing significant solids or other interferences are extracted prior to injection. The sample is analyzed by GC/TEA operating in the nitrogen mode with capillary column capability (30 m × 0.53 mm) and automatic injection. Helium is the carrier gas. The GC system is calibrated with a 100 ppb standard, followed by the samples. The concentration of ethyl carbamate is determined by multiplying peak area ratios by the concentration of the standard. For the distilled spirits, the recovery averaged 92%. The within-labora-tory repeatability (RSDr) ranged from 4.3 to 12.5%, with overall average of 8.0%, and reproducibility (RSDR) varied from 4.8 to 22.0%, with an overall average of 17.4%. For the wines, the recovery averaged 85%, and the RSDr ranged from 8.9 to 42.8%, with an overall average of 34.4%. The method has been adopted first action by AOAC INTERNATIONAL.

Determination of Ethyl Carbamate in Alcoholic Beverages and Soy Sauce by Gas Chromatography with Mass Selective Detection: Collaborative Study

1994 ◽  
Vol 77 (6) ◽  
pp. 1530-1536 ◽  
Author(s):  
Benjamin J Canas ◽  
Frank L Joe ◽  
Gregory W Diachenko ◽  
Gordon Burns
Keyword(s):  
Gas Chromatography ◽  
Internal Standard ◽  
Ethyl Carbamate ◽  
Soy Sauce ◽  
Alcoholic Beverages ◽  
Selective Detection ◽  
Distilled Spirits ◽  
Relative Standard ◽  
Standard Deviations

Abstract A method using gas chromatography with mass selective detection for the determination of ethyl carbamate (EC; also known as urethane) in alcoholic beverages and soy sauce was collaboratively studied by 17 laboratories including authors’ laboratories. The method uses prepacked columns for extraction of liquids with methylene chloride, and n-propyl carbamate as the internal standard. A practice sample and 6 samples of distilled spirits, fortified wines, table wines, and soy sauces were analyzed by each collaborator. Each matrix included blind duplicates of incurred and fortified EC at 3 levels. Distilled spirits contained 50–330 ng EC/g (ppb), fortified wine 40–160 ppb, table wine 10–50 ppb, and soy sauce 15–70 ppb. The ranges of the repeatability relative standard deviations, excluding outliers, were 4.03–6.63% for distilled spirits, 4.01–5.05% for fortified wine, 3.94–6.73% for table wine, and 4.70–8.49% for soy sauce. The ranges of the reproducibility relative standard deviations, excluding outliers, were 8.53–9.49% for distilled spirits, 6.84–12.02% for fortified wine, 8.86–18.47% for table wine, and 13.87–27.37% for soy sauce. Recoveries of added EC ranged from 87 to 93%. Recoveries relative to reference values, labeled as the internal standard, obtained by using gas chromatography/ tandem mass spectrometry with a triple quadrupole mass spectrometer ranged from 89 to 100%.

scholarly journals Determination of N-Octyl Bicycloheptene Dicarboximide, Pyrethrins, and Butylcarbityl 6-Propylpiperonyl Ether in Technical Materials, Concentrates, and Finished Products by Capillary Gas Chromatography: Collaborative Study

1998 ◽  
Vol 81 (3) ◽  
pp. 503-512 ◽  
Author(s):  
Khanh T Nguyen ◽  
Richard Moorman ◽  
Virginia Kuykendall ◽  
◽  
L Bura ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Collaborative Study ◽  
Piperonyl Butoxide ◽  
Capillary Gc ◽  
Split Injection ◽  
Flame Ionization ◽  
Accuracy And Precision ◽  
Insecticidal Compounds

abstract Nineteen collaborating laboratories (including the authors') analyzed 6 blind, duplicate pairs of various technical materials, pyrethrum extracts, concentrates, and finished products by split injection capillary gas chromatography (GC) with flame ionization detection. This procedure simultaneously quantitates with speed, ease, accuracy, and precision all 6 insecticidal compounds in pyrethrum: pyrethrin I, jasmolin I, cinerin I, pyrethrin II, jasmolin II, and cinerin II, as well as butylcarbityl 6-propylpiperonyl ether (BPE, the predominant compound in technical piperonyl butoxide, also commonly known as piperonyl butoxide) and both the endo and exo isomers of N-octyl bicycloheptene dicarboximide (MGK 264). Repeatability ranged from 4.28 to 7.22% for total pyrethrins, from 2.41 to 7.04% for BPE, and from 2.20 to 4.91 % for total MGK 264. Reproducibility ranged from 5.22 to 9.71 % for total pyrethrins, from 4.37 to 7.04% for BPE, and from 2.66 to 6.01 % for total MGK 264. The capillary GC method for these insecticidal compounds in technical materials, concentrates, and finished products has been adopted first action by AOAC INTERNATIONAL.

Determination of volatile alcohols and acetone in serum by non-polar capillary gas chromatography after direct sample injection.

1984 ◽  
Vol 30 (10) ◽  
pp. 1672-1674 ◽  
Author(s):  
N B Smith
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Capillary Column ◽  
Internal Standard ◽  
Fused Silica ◽  
Gas Chromatograph ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Split Ratio

Abstract In this method for detection and quantification of volatile alcohols by capillary gas chromatography, the serum sample is deproteinized, then directly injected into the gas chromatograph with 1-propanol as the internal standard. The capillary column is a 30-m bonded methylsilicone-coated, fused-silica column. With helium as the carrier gas, the injector inlet is set at a split ratio of 1/30 and the average linear velocity in the column is 25 cm/s. Injector and flame-ionization detector temperatures are 280 degrees C, oven temperature 35 degrees C. Chromatography time is less than 3 min.

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.

Surrogate-Assisted Determination of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin in Fish by Electron Capture Capillary Gas Chromatography

1986 ◽  
Vol 69 (6) ◽  
pp. 976-980
Author(s):  
Richard A Niemann
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Capillary Gas Chromatography ◽  
Capillary Column ◽  
Electron Capture Detection ◽  
Matrix Interference ◽  
Relative Standard ◽  
Tetrachlorodibenzo P Dioxin ◽  
Liquid Chromatographic

Abstract Surrogate spiking the sample with 1000 parts per trillion (pptr) 1,3,7,8-tetrachlorodibenzo-p-dioxin (1378-TCDD) has doubled analytical throughput in determining toxic 2378-TCDD (analyte) at the low partper- trillion level in fish, using multicolumn high resolution liquid chromatographic cleanup before quantitation by capillary gas chromatography with electron capture detection. The 1378- and 2378-TCDD were recovered equally and were well separated by the capillary column so that the earlier-eluting surrogate did not interfere with the quantitation of levels of analyte many-fold lower. Matrix interference contributed <1 % bias in surrogate quantitation. Using surrogate recovery to correct for analyte losses during analysis, accuracy averaged (n = 7) 105% in determining 18 or 45 pptr 2378-TCDD added to fish without detectable bioincurred analyte. Analyses of selected fish with bioincurred 2378-TCDD gave results comparable to earlier work where recovery correction required a second analysis of sample fortified with analyte. With surrogate fortification, repeatability of determination (n = 3 or 4) improved markedly to <5% relative standard deviation at 37-46 pptr.

Determination of N-Nitrosodimethylamine in Nonfat Dry Milk: Collaborative Study

1984 ◽  
Vol 67 (2) ◽  
pp. 232-236
Author(s):  
Nrisinha P Sen ◽  
Stephen Seaman ◽  
K Karpinsky ◽  
◽  
M Castegnaro ◽  
...  
Keyword(s):  
Thermal Energy ◽  
Collaborative Study ◽  
Sulfamic Acid ◽  
Complete Data ◽  
Energy Analyzer ◽  
Coefficients Of Variation ◽  
Dry Milk ◽  
Repeatability And Reproducibility ◽  
Nonfat Dry Milk

Abstract Ten laboratories participated in a collaborative study of a method for the determination of JV-nitrosodimethylamine (NDMA) in nonfat dry milk. NDMA is eluted with dichloromethane from a mixture of Celite, acidic sulfamic acid, and nonfat dry milk (all packed in a chromatography column), concentrated in a Kuderna-Danish concentrator, and finally analyzed by a GC-thermal energy analyzer technique. Ten samples were studied: 6 were naturally contaminated (NDMA levels 0.38- 3.56 ppb) and 4 were spiked with known levels (0.96 and 3.2 ppb) of NDMA. The coefficients of variation (CV) of the complete data for the naturally contaminated samples (excluding the 2 samples containing the lowest levels) were 8.5% and 22.5% for repeatability and reproducibility, respectively. The corresponding CVs for the spiked samples were 14.4% and 20.4%, respectively. The percent recoveries of the added NDMA in the spiked samples (at the 2 levels indicated above) were 101.6 ± 3.2 (omitting 1 outlier) and 95 ∓ 2.1, respectively. The method has been adopted official first action.

scholarly journals Quantitative Determination of Trans-Fatty Acids in Oils and Fats by Capillary Gas Chromatography: Results of a JOCS Collaborative Study

2007 ◽  
Vol 56 (8) ◽  
pp. 405-415 ◽  
Author(s):  
Seiichi Shirasawa ◽  
Makoto Shiota ◽  
Hiroshi Arakawa ◽  
Yasuhiko Shigematsu ◽  
Kazuhisa Yokomizo ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Gas Chromatography ◽  
Quantitative Determination ◽  
Capillary Gas Chromatography ◽  
Trans Fatty Acids ◽  
Collaborative Study

scholarly journals Determination of Residues of Eight Synthetic Pyrethroids in Tobacco by Capillary Gas Chromatography

1994 ◽  
Vol 16 (2) ◽  
pp. 65-75
Author(s):  
BS Dattilo ◽  
S Gallo ◽  
G Lionetti
Keyword(s):  
Gas Chromatography ◽  
Film Thickness ◽  
Stationary Phase ◽  
Capillary Gas Chromatography ◽  
Capillary Column ◽  
Limit Of Detection ◽  
Synthetic Pyrethroids ◽  
Gas Chromatograph ◽  
Limit Of Determination

AbstractA method was developed for the simultaneous determination of the residues of the following eight synthetic pyrethroids and their isomers in tobacco: tetramethrin, permethrin, cyfluthrin, cypermethrin, alfamethrin, flucythrinate, fluvalinate and deltamethrin. The pesticides were extracted from ground tobacco by means of acetone:water 9:1 for 5 hours. The extract was diluted with water and partitioned into n-hexane. The organic phase was concentrated to about 1 ml and then purified by a Florisil-SPE column. The gas-chromatographic analyses were run with a gas-chromatograph Carlo Erba Series Mega HRGC 5300 equipped with a capillary column (stationary phase OV-1 - 0.10-0.15 µm film thickness, 25 m long) and a 63Ni electron-capture detector. Two different injection ports were used: split-splitless and cold split-splitless, working both with isothermal and programmed temperatures. Both the limit of detection and the limit of determination were estimated for each compound. Recoveries from fortified samples at level of 1 µgKg-1 are reported.

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