scholarly journals Determination of Oligofructose, a Soluble Dietary Fiber, by High-Temperature Capillary Gas Chromatography

2000 ◽  
Vol 83 (4) ◽  
pp. 1020-1026 ◽  
Author(s):  
Dirk Joye ◽  
Hubert Hoebregs

Abstract A high-temperature capillary gas chromatographic method was developed for the quantitative determination of oligofructose in foods and food products. Sample preparation involves oxymation and silylation of the extracted sugars. The oximetrimethylsilyl derivatives are analyzed on an apolar capillary column, with detection by flame ionization. The method is accurate, with recovery of spiked samples at >96%. Repeatability was excellent; RSD values of 1.1% were obtained. Other common oligosaccharides, such as malto-, isomalto-, and galactooligosaccharides, and levan do not interfere, making the method specific and reliable.

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.


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.


1974 ◽  
Vol 20 (2) ◽  
pp. 249-254 ◽  
Author(s):  
M A Evenson ◽  
G L Lensmeyer

Abstract A rapid, simple, accurate, and precise isothermal gas-chromatographic method is introduced for determination of methaqualone (2-methyl-3-o-tolyl-4(3H)-quinazolinone) in serum. A single extraction of 2 ml of serum, without derivative formation, will give adequate sensitivity for quantitation of therapeutic serum concentrations of the drug within 15 min. The method is free of interferences from biological substances, as well as from commonly used drugs. A non-drug internal standard compensates for variables in extraction, injection, and instrumental changes during analysis. The coefficient of variation, day-to-day, is 5.6%. Mean recovery of added methaqualone was 80%. To compensate for the nonquantitative yield and ensure accurate results, we prepared all analytical methaqualone standards in serum.


1970 ◽  
Vol 53 (3) ◽  
pp. 566-568
Author(s):  
J E Paterson

Abstract A gas chromatographic method is described for the quantitative determination of dioxathion and chlorfenvinphos in emulsifiable concentrates and livestock dips. A convenient quantity of the emulsifiable formulation is dissolved in xylene and the aqueous dip is extracted with xylene for gas chromatographic analysis, using a mixed silicone oil stationary phase and a flame ionization detector. The coefficients of variation for the dioxathion and chlorfenvinphos determinations in the emulsifiable concentrate are 2.4 and 1.0%, respectively. Recoveries of the former from a fouled dip ranged from 97 to 103% and recoveries of the latter ranged from 92 to 97%.


1974 ◽  
Vol 57 (1) ◽  
pp. 189-191
Author(s):  
James B Leary

Abstract A gas chromatographic method is described for determining acephate (O,S-dimethyl acetylphosphoramidothioate) and a metabolite, Ortho 9006 (O,S-dimethyl phosphoramidothioate), in a variety of crops. After extraction of the sample with ethyl acetate, the solvent is evaporated, and an ether solution of the residue is passed through a silica gel column to remove interferences. Acephate and Ortho 9006 are eluted from the column with 10% methanol in ether and measured simultaneously by programmed temperature gas chromatography, using an alkali flame ionization detector.


1987 ◽  
Vol 70 (1) ◽  
pp. 55-57
Author(s):  
Daniel E Terry

Abstract A gas chromatographic method for the determination of isofenphos (OFTANOL®) in isofenphos technical and liquid formulations has been developed and collaboratively studied by 11 laboratories. Two technical samples and 2 liquid flowable samples were analyzed after shaking/extracting in methanol which contained diisobutyl phthalate as an internal standard. The extracts were analyzed by gas chromatography using an SP-2100 column and either flame ionization or thermal conductivity detection. Coefficients of variation were 0.57 and 1.27% for the technical and formulated products, respectively. The GC method has been adopted official first action as a AOACCTPAC method.


1979 ◽  
Vol 62 (4) ◽  
pp. 931-936
Author(s):  
Thomas J Birkel ◽  
Charles R Warner ◽  
Thomas Fazio

Abstract A gas chromatographic method is presented for the quantitative determination of 1,4- dioxane in polysorbate 60 and polysorbate 80. Dioxane is isolated from the matrix by closedsystem vacuum distillation with water as the carrier solvent. The distillate is chromatographed on Chromosorb 104 and detected by flame ionization. Recoveries of dioxane from polysorbate 60 samples fortified at 0.5, 1, 2, and 20 ppm averaged 90, 91, 85, and 75%, respectively. Recoveries from polysorbate 80 fortified at the same levels averaged 100, 88, 95, and 95%, respectively. Samples of polysorbate 60 and polysorbate 80 were found to contain from 5.5 to 378 ppm dioxane.


1968 ◽  
Vol 14 (7) ◽  
pp. 595-609 ◽  
Author(s):  
Irving Sunshine ◽  
Robert Maes ◽  
Rosalie Faracci

Abstract A gas chromatographic method for the quantitative determination of glutethimide was developed. This method was applied to samples obtained from patients who were comatose because of acute glutethimide intoxication. The results obtained from this procedure were compared with those obtained by using an ultraviolet method. The patients’ clinical conditions were assessed and correlated with the blood concentrations of glutethimide. The samples were processed to isolate glutethimide, as well as its metabolites. The metabolites were separated using thin-layer chromatography and were checked for purity by both thin-layer and gas chromatography.


2019 ◽  
Vol 70 (2) ◽  
pp. 555-559
Author(s):  
Anca Maria Juncan ◽  
Luca Liviu Rus ◽  
Felicia Gabriela Gligor ◽  
Claudiu Morgovan

A gas chromatographic method was applied by using the GC-FID tehnique for the determination of a-tocopherol acetate in an anti-aging properly developed cosmetic formulation. A simple methanol:acetonitrile organic solvent mixture (50:50v/v) was required for sample preparation and the separation of the studied compound was carried out in specific chromatographic conditions. The analysis was carried out in proper developed anti-aging cream sample and satisfactory results were obtained for the recovery of the studied compound.


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