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 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

Gas Chromatographic Determination of Ethyl O,O-Dimethyldithiophosphoryl- 1-Phenyl Acetate in Technical Grade Cidial and Its 50% Liquid Formulation

1969 ◽  
Vol 52 (1) ◽  
pp. 52-55
Author(s):  
B Bazzi ◽  
L Abbruzzese ◽  
G Galluzzi
Keyword(s):  
Thermal Conductivity ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Phenyl Acetate ◽  
Thermal Conductivity Detector ◽  
Liquid Formulation ◽  
Technical Grade ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method has heen developed for analysis of ethyl O,O-dimethyldithiophosphoryl- 1-phenyl acetate. The insecticide or a convenient amount of an insecticidal preparation is dissolved in toluene, together with a suitable 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 found.

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.

Gas Chromatographic Determination of Propionic Acid and Sodium and Calcium Propionate in Bread and Cake1

1983 ◽  
Vol 46 (4) ◽  
pp. 284-286 ◽  
Author(s):  
YASUHIDE TONOGAI ◽  
AMARA KINGKATE ◽  
WANTHANEE THANISSORN ◽  
UDOMKIAT PUNTHANAPRATED
Keyword(s):  
Detection Limit ◽  
Phosphoric Acid ◽  
Ethyl Acetate ◽  
Propionic Acid ◽  
Chromatographic Determination ◽  
Accurate Method ◽  
Gas Chromatograph ◽  
Calibration Curves ◽  
Calcium Propionate

A simple and accurate method for determination of propionic acid and sodium and calcium propionate was developed. These compounds were simultaneously extracted with ethyl acetate made acidic with phosphoric acid. The extract was injected directly into the gas chromatograph. Calibration curves of the three compounds ranged from 25–125mu;g/ml. The detection limit of these compounds were 25 ppm by this method. Commercial biscuits, breads and cakes were analyzed by this method and all of them contained less than the limit permitted by Thai regulations.

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%.

Liquid Chromatographic Determination of Sulfamoyldapsone in Swine Tissues

1987 ◽  
Vol 70 (6) ◽  
pp. 1031-1032
Author(s):  
Yuuko S Endoh ◽  
Ryozo Yamaoka ◽  
Nobuo Sasaki
Keyword(s):  
Detection Limit ◽  
Quantitative Determination ◽  
Chromatographic Determination ◽  
Alumina Column ◽  
Average Recovery ◽  
Diaminodiphenyl Sulfone ◽  
Alumina Column Chromatography ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method is described for the quantitative determination of sulfamoyldapsone (2-sulfamoyl-4,4'-diaminodiphenyl sulfone) in swine muscle, liver, kidney, and fat. Sulfamoyldapsone was extracted from tissues with acetonitrile saturated with n-hexane. The extract was washed with n-hexane saturated with acetonitrile, concentrated, and cleaned up by alumina column chromatography. Sulfamoyldapsone was separated on an ODS column by using acetonitrile-methanol-water (6 + 18 + 76) and was detected at 292 nm. Overall average recovery of sulfamoyldapsone added to tissues at levels of 0.1 and 0.5 /μg/g was 93.3% ± 6.0. Detection limit was 0.02 μg/g in these tissues.

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