DETERMINATION OF WATER IN FERMENTED FEEDS BY GAS CHROMATOGRAPHY

1981 ◽  
Vol 61 (3) ◽  
pp. 827-831 ◽  
Author(s):  
T. W. FENTON ◽  
MIRJANA FENTON ◽  
G. W. MATHISON
Keyword(s):  
Thermal Conductivity ◽  
Gas Chromatography ◽  
Chemical Method ◽  
Thermal Conductivity Detector ◽  
Gas Chromatograph ◽  
Water Determination ◽  
Chromatographic Procedure

A gas chromatographic procedure for measuring water in fermented feeds was developed and evaluated. The method involves extracting the water with alcohol followed by the separation of the water and alcohol with a Porapak QS column in a gas chromatograph equipped with a thermal conductivity detector. Linear responses were obtained when the ratios of the peak area of water to alcohol were plotted against the weight ratios of water to alcohol (mg/g). The method has the advantage of being very fast, and is as accurate as a chemical method used for water determination.

scholarly journals Experiments with a cyclic closed-loop gas chromatograph

1984 ◽  
Vol 62 (11) ◽  
pp. 2260-2263
Author(s):  
Roberta Back ◽  
R. A. Back
Keyword(s):  
Thermal Conductivity ◽  
Gas Chromatography ◽  
Closed Loop ◽  
Thermal Conductivity Detector ◽  
Gas Chromatograph ◽  
Peak Broadening ◽  
Equivalent Length ◽  
Length Separation ◽  
Carrier Gases ◽  
Better Than

A cyclic closed-loop gas chromatrograph, comprising a column, a thermal conductivity detector, and a peristaltic circulating pump, together with valves for sample pick-up and carrier gas admission, is described. Injected samples could be recycled many times, providing very long effective column lengths, and separations were markedly better than on a single-pass column of equivalent length. Separation of two components, and peak broadening with single components, were measured over many successive cycles for a variety of samples, carrier gases, and conditions. The use of the cyclic chromatograph for testing columns and for studying basic processes in gas chromatography is demonstrated and discussed.

scholarly journals New Method of Denitrification Analysis of Bradyrhizobium Field Isolates by Gas Chromatographic Determination of 15N-Labeled N2

2004 ◽  
Vol 70 (5) ◽  
pp. 2886-2891 ◽  
Author(s):  
Reiko Sameshima-Saito ◽  
Kaori Chiba ◽  
Kiwamu Minamisawa
Keyword(s):  
Thermal Conductivity ◽  
Detection Limit ◽  
Bradyrhizobium Japonicum ◽  
Chromatographic Determination ◽  
New Method ◽  
Thermal Conductivity Detector ◽  
Gas Chromatograph ◽  
Carrier Gas ◽  
Field Isolates

ABSTRACT To evaluate the denitrification abilities of many Bradyrhizobium field isolates, we developed a new 15N-labeled N2 detection methodology, which is free from interference from atmospheric N2 contamination. 30N2 (15N15N) and 29N2 (15N14N) were detected as an apparent peak by a gas chromatograph equipped with a thermal conductivity detector with N2 gas having natural abundance of 15N (0.366 atom%) as a carrier gas. The detection limit was 0.04% 30N2, and the linearity extended at least to 40% 30N2. When Bradyrhizobium japonicum USDA110 was grown in cultures anaerobically with 15NO3 −, denitrification product (30N2) was detected stoichiometrically. A total of 65 isolates of soybean bradyrhizobia from two field sites in Japan were assayed by this method. The denitrification abilities were partly correlated with filed sites, Bradyrhizobium species, and the hup genotype.

scholarly journals Determination of Carbon Monoxide in Tuna by Gas Chromatography with Micro-Thermal Conductivity Detector

2008 ◽  
Vol 46 (5) ◽  
pp. 392-394 ◽  
Author(s):  
C. Bernardi ◽  
L. M. Chiesa ◽  
S. Soncin ◽  
E. Passero ◽  
P. A. Biondi
Keyword(s):  
Thermal Conductivity ◽  
Gas Chromatography ◽  
Carbon Monoxide ◽  
Thermal Conductivity Detector

scholarly journals Study on the Correction Factor in the Determination of Fatty Acid Composition by a Gas Chromatograph with a Thermal Conductivity Detector

1973 ◽  
Vol 22 (2) ◽  
pp. 102-105
Author(s):  
Shoichiro WATANABE ◽  
Satoshi NAKASATO ◽  
Hideo KUWAYAMA ◽  
Yukihiro SASAMOTO ◽  
Shinsaku SHIRAISHI ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Acid Composition ◽  
Correction Factor ◽  
Thermal Conductivity Detector ◽  
Gas Chromatograph

scholarly journals VALIDATION OF ANALYTICAL METHOD FOR DETERMINATION OF HIGH LEVEL CARBON DIOXIDE (CO2) IN NITROGEN GAS (N2) MATRIX USING GAS CHROMATOGRAPHY THERMAL CONDUCTIVITY DETECTOR

2015 ◽  
Vol 12 (24) ◽  
pp. 7-16
Author(s):  
Harry BUDIMAN ◽  
Oman ZUAS
Keyword(s):  
Carbon Dioxide ◽  
Thermal Conductivity ◽  
Gas Chromatography ◽  
Limit Of Detection ◽  
Good Precision ◽  
Thermal Conductivity Detector ◽  
Limit Of Quantitation ◽  
Carbon Dioxide Co2 ◽  
High Level

High accurate result of carbon dioxide (CO2) measurement is of great importance since the result (data) is used as the foundation for decision making related to regulated monitoring program and law enforcement. In this study, therefore, method for measurement of high level of carbon dioxide (CO2) in nitrogen (N2) matrix using gas chromatography thermal conductivity detector (GC-TCD) was validated to achieve the optimum performance of the method. For this purposes, identity confirmation, selectivity, limit of detection (LoD), limit of quantitation (LoQ), repeatability, reproducibility, accuracy, and linearity of the method were evaluated. The result shows that the GC-TCD method has good precision in term of repeatability and reproducibility having values of 0.07 and 0.37%, respectively. No bias of the method can be found and an excellent linearity of the method was obtained in the range of 2 - 13.97% mol/mol. Thus, based on the result evaluation under given criteria of this study, it can be concluded that the GC-TCD method is reliable and suitable for determination of high level of CO2 in N2 matrix.

Gas Chromatographic Determination of O,O-Diethyl S-(N-Isopropylcarbamoylmethyl) Phosphorothiolothionate (Prothoate) in Technical Products and Liquid Formulations

1972 ◽  
Vol 55 (6) ◽  
pp. 1336-1338
Author(s):  
Brunetto Bazzi ◽  
Guglielmo Galluzzi ◽  
Luigi Abruzzese
Keyword(s):  
Thermal Conductivity ◽  
Gas Chromatography ◽  
Chromatographic Method ◽  
Concentration Level ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Thermal Conductivity Detector ◽  
Gas Chromatographic Method ◽  
Technical Products

Abstract A gas chromatographic method has been developed for the analysis of O,O-diethyl S-(N-isopropylcarbamoylmethyl) phosphorothiolothionate . The acaricide or a convenient amount of an acaricidal preparation is dissolved in xylene, together with malathion as an internal standard, and analyzed by gas chromatography, using a thermal conductivity detector. The precision (P = 0.05) of the method is ±1.5% of the concentration level.

Improved Cleanup and Derivatization for Gas Chromatographic Determination of Monosodium Glutamate in Foods

1983 ◽  
Vol 66 (6) ◽  
pp. 1528-1531 ◽  
Author(s):  
Hiroshi Nakanishi
Keyword(s):  
Glutamic Acid ◽  
Acid Derivative ◽  
Monosodium Glutamate ◽  
Chromatographic Determination ◽  
Flame Ionization Detection ◽  
Gas Chromatograph ◽  
Flame Ionization ◽  
Acetone Water ◽  
Chromatographic Procedure

Abstract A gas chromatographic procedure is described for determining monosodium glutamate (MSG) in several types of food. A sample is extracted with acetone- water (1 + 1). Acetone is evaporated and an aliquot of the extract is buffered with 1M NH4OH-1M NH4CI pH 9 solution, and chromatographed directly on a column of QAE Sephadex A-25 that has been pretreated with the same buffer. MSG is eluted with 0.1N HC1, and a portion of the eluate is evaporated to dryness and reacted with dimethylformamide( DMF)-dimethylacetal to form the glutamic acid derivative, which is injected into a gas chromatograph and measured by flame ionization detection. Recoveries of MSG from sample fortified at 5-500 mg ranged from 92.8 to 100%.

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