Antioxidants (BHA and BHT) in Breakfast Cereals

1965 ◽  
Vol 48 (4) ◽  
pp. 694-699
Author(s):  
David M Takahashi
Keyword(s):  
Gas Chromatography ◽  
Petroleum Ether ◽  
Chromatographic Method ◽  
Steam Distillation ◽  
Gas Chromatograph ◽  
Breakfast Cereals ◽  
Collaborative Studies ◽  
Different Types ◽  
Gas Chromatographic Method

Abstract Antioxidants (BHA and BHT) in different types of breakfast cereals were studied by argon ionization gas chromatography. Samples containing antioxidants were packed into the column, and antioxidants were eluted with redistilled petroleum ether. EIuates were concentrated under N2 and injected into a Barber-Colman Model 10 gas chromatograph. Recoveries ranged from about 92 to 110%. Results obtained by steam distillation-colorimetry methods were erratic. Colorimetric procedures were not free from interferences and could lead to highly erroneous results at the lower ppm levels. The gas chromatographic method is faster, simpler, and more accurate. Collaborative studies on corn and rice ready-to-eat breakfast cereals are recommended.

Determination of Menthol in Honey by Gas Chromatography

1993 ◽  
Vol 76 (6) ◽  
pp. 1289-1295 ◽  
Author(s):  
Li Maojuan ◽  
Donald L Nelson ◽  
Peter Sporns
Keyword(s):  
Gas Chromatography ◽  
Room Temperature ◽  
Chromatographic Method ◽  
Steam Distillation ◽  
Internal Standard ◽  
Acarapis Woodi ◽  
Hexane Extraction ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method was developed for the determination of L-menthol in honey at levels as low as 0.1 ppm. The method includes steam distillation and hexane extraction with an internal standard (2,6-dimethylphenol). Beehives treated to control Acarapis woodi over 21 days with 30-60 g L-menthol contained L-menthol residues in honey and beeswax. L-menthol was found only in treated portions of the hive and not later transferred to added honey supers. The highest levels of residues in honey (18 ppm) and beeswax (2790 ppm) were found when pure L-menthol was adsorbed into foam strips placed on top of the hives. L-menthol residues in honey were not reduced by storage in open containers at room temperature for up to 55 days. Untrained panelists could not detect L-menthol in honey until the levels approached 36 ppm.

Determination of Trifluralin in Formulations by Gas Chromatography

1971 ◽  
Vol 54 (1) ◽  
pp. 125-127
Author(s):  
Larry G Hambleton
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Flame Ionization Detector ◽  
Gas Chromatograph ◽  
Ionization Detector ◽  
Average Recovery ◽  
Flame Ionization ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method has been developed that is rapid and specific for trifluralin in formulations. The sample is extracted with acetone, an internal standard is added, and the solution is diluted to volume and injected into a gas chromatograph equipped with a flame ionization detector. Three typical trifluralin formulations were analyzed by both the gas chromatographic method and an ultraviolet method. The gas chromatographic method gave an average recovery of 101.2%.

Gas Chromatographic Determination of Carbetamide Residues in Rape and Soil

1989 ◽  
Vol 72 (4) ◽  
pp. 660-662
Author(s):  
Jia-Lun Wu ◽  
De-Fang Fan
Keyword(s):  
Gas Chromatography ◽  
Petroleum Ether ◽  
Chromatographic Method ◽  
Direct Determination ◽  
Chromatographic Determination ◽  
Soil Samples ◽  
Nitrogen Phosphorus Detector ◽  
Gas Chromatographic Method ◽  
Nitrogen Phosphorus

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.

The Importance of Alcohol Testing by Gas Chromatography vs the Cordebard Classical Method Modified in the Medico Legal Investigation

2018 ◽  
Vol 69 (9) ◽  
pp. 2407-2410
Author(s):  
Dan Perju Dumbrava ◽  
Carmen Corina Radu ◽  
Sofia David ◽  
Tatiana Iov ◽  
Catalin Jan Iov ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Method ◽  
Classical Method ◽  
Blood Alcohol Concentration ◽  
Alcohol Concentration ◽  
Blood Alcohol ◽  
Technical Details ◽  
Gas Chromatographic Method ◽  
Alcohol Testing ◽  
Living Person

Considering the growing number of requests from the criminal investigations authorities addressed to the institutions of legal medicine, testing of blood alcohol concentration both in the living person and in the corpse, we believe that a presentation of the two methods which are used in our country, is a topic of interest at present. The purpose of this article is to provide the reader with the technical details on how blodd alcohol concentration is realised by means of the gas chromatographic method and the classical one, (Cordebard modified by D. Banciu and I. Droc) respectively. Another purpose of this article is to also show, in a comparative way, the elements that make the gas chromatographic method superior to the former one.

Gas Chromatographic Determination of N-Butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine and α,α,α-Trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine in Formulations

1971 ◽  
Vol 54 (3) ◽  
pp. 711-712
Author(s):  
Martha Fuzesi
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Electron Capture ◽  
Chromatographic Method ◽  
Chromatographic Determination ◽  
Electron Capture Detector ◽  
Reference Solution ◽  
Gas Chromatographic Method

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.

scholarly journals The Use of Cryogenic Temperature Gas Chromatography for the Determination of Carbon Monoxide and Carbon Dioxide in Cigarette Smoke

1972 ◽  
Vol 6 (4) ◽  
Author(s):  
G.P. Morie ◽  
C.H. Sloan
Keyword(s):  
Carbon Dioxide ◽  
Gas Chromatography ◽  
Carbon Monoxide ◽  
Liquid Nitrogen ◽  
Cigarette Smoke ◽  
Cryogenic Temperature ◽  
Chromatographic Method ◽  
Porapak Q ◽  
Gas Chromatographic Method

AbstractA gas chromatographic method for the determination of carbon monoxide and carbon dioxide in cigarette smoke was developed. A column containing Porapak Q packing and a cryogenic temperature programmer which employed liquid nitrogen to cool the column to subambient temperatures was used. The separation of N

Gas-chromatographic method for plasma acetate analysis in acetate-intolerance studies.

1978 ◽  
Vol 24 (2) ◽  
pp. 348-350 ◽  
Author(s):  
L G Nielsen ◽  
K O Ash ◽  
E Thor
Keyword(s):  
Chromatographic Method ◽  
Hemodialysis Patients ◽  
Flame Ionization Detector ◽  
Gas Chromatograph ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Single Column ◽  
Gas Chromatographic Method

Abstract We describe a modified gas-chromatographic method for acetate in serum or plasma, intended for use in the investigation of acetate intolerance in hemodialysis patients. The assay may be adapted for use with a single-column gas chromatograph equipped with a flame ionization detector. The analysis, made isothermally, requires only 0.5 ml of plasma or serum. Only one deproteinizing step is required to prepare the sample for analysis. Additionally, we present preliminary findings of an ongoing acetate-intolerance study.

Comparison of Emmerie-Engel Method and Gas Chromatographic Method for Determination of Supplemental α-Tocopheryl Acetate in Feed Concentrates

1987 ◽  
Vol 70 (3) ◽  
pp. 417-419
Author(s):  
Michael P Labadie ◽  
Charles E Boufford
Keyword(s):  
Gas Chromatography ◽  
Vitamin E ◽  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Tocopheryl Acetate ◽  
High Potency ◽  
Gc Analysis ◽  
Gas Chromatographic Method ◽  
Official Procedure

Abstract The determination of supplemental a-tocopheryl acetate in high potency vitamin E powders and oils was compared using the Emmerie- Engel method and gas chromatography (GC). The Emmerie-Engel reaction requires saponification, extraction of the saponiflable fracaon, and quantitation by colorimetry. GC analysis requires only an extraction and/or dilution before quantitation. These are represented essentially by AOAC methods 43.147-43.151 (colorimetry) and 43.152-43.159 (GC) for high potency vitamin E concentrates. Each method was statistically evaluated for precision and sample-to-sample reproducibility. Each Emmerie-Engel value was divided by the GC value obtained for the same sample; an average of 1.049 with a coefficient of variation of 2.89% was obtained. It was concluded that (he GC procedure was superior to the Emmerie-Engel method, and ahould be the official procedure for determination of supplemental a-tocopheryl acetate in feed concentrates.

Capillary Column Gas Chromatographic Determination of Trace Residues of the Herbicide Chlorsulfuron in Agricultural Runoff Water

1987 ◽  
Vol 70 (4) ◽  
pp. 745-748
Author(s):  
Uaz Ahmad
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Method ◽  
Capillary Column ◽  
Methylene Chloride ◽  
Chromatographic Determination ◽  
Agricultural Runoff ◽  
Runoff Water ◽  
Florisil Column ◽  
Gas Chromatographic Method

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.

Assay of NF Ethylene by Gas Chromatography

1972 ◽  
Vol 55 (5) ◽  
pp. 1067-1069
Author(s):  
N Aubrey Carson
Keyword(s):  
Atmospheric Pressure ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Thermal Conductivity Detector ◽  
Gas Chromatograph ◽  
Gas Sampling ◽  
Gas Chromatographic Method ◽  
Standard Gas

Abstract A gas chromatographic method, utilizing a 6′ × 1/4″ Poropak R column and a thermal conductivity detector, was developed for the analysis of NF ethylene. The sample was introduced into the gas chromatograph at atmospheric pressure, using a gas sampling valve with calibrated loop. A high purity standard gas was used for comparison. With the instrument set for optimum operating conditions the precision for multiple injections of standard gas was excellent. The assay value of a sample was found to be 99.7%, when determined on 3 separate days. A collaborative study of the method is recommended.

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