Preliminary Studies on Weathering of Chlordane Residues

1965 ◽  
Vol 48 (5) ◽  
pp. 952-954
Author(s):  
Alfred D Thruston
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Plant Extracts ◽  
Room Temperature ◽  
Agricultural Products ◽  
Qualitative And Quantitative ◽  
Chromatographic Peaks ◽  
The Many ◽  
Ppm Level

Abstract The qualitative and quantitative determination of chlordane residues on raw agricultural products has been best achieved by gas chromatography techniques. While good recoveries (90–100% at the 0.1 ppm level) have been obtained from plant extracts with added standard chlordane, weathered chlordane residues show changes in number and size of gas chromatographic peaks. Chlordane at the 50 µg level, when exposed to the air at room temperature over a period of time, showed progressive decomposition and loss of the many components that make up chlordane.

Qualitative and Quantitative Determination of Methaqualone in Serum by Gas Chromatography

1974 ◽  
Vol 20 (2) ◽  
pp. 249-254 ◽  
Author(s):  
M A Evenson ◽  
G L Lensmeyer
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Serum Concentrations ◽  
Single Extraction ◽  
Qualitative And Quantitative ◽  
Gas Chromatographic Method ◽  
Isothermal Gas

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.

Qualitative and quantitative determination of extractives in heartwood of Scots pine (Pinus sylvestris L.) by gas chromatography

2006 ◽  
Vol 1109 (2) ◽  
pp. 267-272 ◽  
Author(s):  
Dag Ekeberg ◽  
Per-Otto Flæte ◽  
Morten Eikenes ◽  
Monica Fongen ◽  
Carl Fredrik Naess-Andresen
Keyword(s):  
Gas Chromatography ◽  
Pinus Sylvestris ◽  
Quantitative Determination ◽  
Scots Pine ◽  
Qualitative And Quantitative

Quantitative Determination of Medazepam, Diazepam, and Nitrazepam in Whole Blood by Flame-Ionization Gas—liquid Chromatography

1974 ◽  
Vol 20 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Mavis S Greaves
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Whole Blood ◽  
Chromatographic Analysis ◽  
Gas Liquid Chromatography ◽  
Trimethylsilyl Derivative ◽  
Ionization Detector ◽  
Qualitative And Quantitative ◽  
Flame Ionization

Abstract Accurate methods are described for the qualitative and quantitative determination of medazepam, diazepam, and nitrazepam in 5 ml of whole blood. Medazepam and diazepam are analyzed intact and nitrazepam is chromatographed as its trimethylsilyl derivative by flame-ionization gas-chromatography on "1% OV-17." A supplementary column of "2% OV-1" is used to separate nitrazepam TMS from diazepam when both are present in the same extract. Essential data given include the percentage recovery of medazepam, and the flame-ionization detector responses of diazepam and silylated nitrazepam relative to medazepam, calculated after extraction from blood and gas-chromatographic analysis. Chromatograms are illustrated of extracts of blood taken from patients on medazepam and diazepam therapy and from a patient who had taken an overdose of nitrazepam.

scholarly journals Methods for the Quantitative Determination of Biocides in Tobacco and Tobacco Products: Part VI: A Modified Procedure for Organochlorine, Organophosphorus and Carbamate Insecticide Residues in Tobacco

1974 ◽  
Vol 7 (5) ◽  
Author(s):  
E. Nesemann ◽  
F. Seehofer
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Coefficient Of Variation ◽  
Tobacco Products ◽  
Insecticide Residues ◽  
Carbamate Insecticides ◽  
Carbamate Insecticide ◽  
Cleanup Procedure ◽  
Ppm Level

AbstractThe screening procedure for the determination of pesticide residues in tobacco (organochlorine, organophosphorus and carbamate insecticides) published in 1970 has been improved by introduction of the dry-column chromatography as cleanup procedure. A new procedure has been developed for the detection of carbaryl and propoxur by gas chromatography. The extraction and cleanup method developed can be used to determine 11 organochlorine, 11 organophosphorus and 3 carbamate insecticides. The procedure can be applied to determine further insecticides and, in addition, fungicides, herbicides and metabolites. The recoveries of added pesticides at 0.5 ppm level are between 75 and 102 %. The coefficient of variation detected with parathion is 4.4 %

The Determination of Tobacco Additives1st Report: A Method for the Qualitative and Quantitative Determination of Vanillin, Ethylvanillin, Coumarin and Dihydrocoumarin in Tobacco and Tobacco Products/Zur Bestimmung von Tabakadditiven: 1. Mitteilung: Eine Methode zur qualitativen und quantitativen Bestimmung von Vanillin, Aethylvanillin, Cumarin und Dihydrocumarin in Tabak und Tabakerzeugnissen

1970 ◽  
Vol 5 (6) ◽  
Author(s):  
E. Nesemann ◽  
F. Seehofer
Keyword(s):  
Gas Chromatography ◽  
Thin Layer ◽  
Quantitative Determination ◽  
Thin Layer Chromatography ◽  
Screening Method ◽  
Tobacco Products ◽  
Qualitative And Quantitative ◽  
Trimethylsilyl Derivatives ◽  
Layer Chromatography

AbstractA screening method has been developed for the qualitative and quantitative determination of vanillin, ethylvanillin, coumarin and dihydrocoumarin. The compounds are qualitatively determined by thin-layer chromatography after extraction of tobacco and purification of the extract. The quantitative determination is made by gas chromatography: Coumarin and dihydrocoumarin are determined directly and vanillin and ethylvanillin after silylation in the form of trimethylsilyl derivatives. Detection limit: thin-layer chromatography = 1 µg, gas chromatography = 0.02 µg. The coefficient of variation of the results obtained amounts to 2.4 % for vanillin and to 6.7 % for coumarin

scholarly journals Determination of asparagine, glutamine and pyrrolidonecarboxylic acid in total enzymic hydrolysates of peptides and glycopeptides by gas–liquid chromatography

1973 ◽  
Vol 133 (3) ◽  
pp. 551-561 ◽  
Author(s):  
Hedy Hediger ◽  
Richard L. Stevens ◽  
Hans Brandenberger ◽  
Karl Schmid
Keyword(s):  
Amino Acids ◽  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Room Temperature ◽  
Butyl Ester ◽  
Gas Liquid Chromatography ◽  
Qualitative And Quantitative ◽  
Elution Pattern

A new procedure for the qualitative and quantitative determination of asparagine, glutamine and pyrrolidonecarboxylic acid in total enzymic hydrolysates of peptides and glycopeptides based on g.l.c. has been developed. Under the conditions of esterification and trifluoroacetylation N-trifluoroacetylaspartic acid mono-n-butyl ester was formed from asparagine and N-trifluoroacetylglutamic acid mono-n-butyl ester from both glutamine and pyrrolidonecarboxylic acid. To distinguish between the latter two compounds, the esterification was carried out at room temperature yielding 30% of esterified pyrrolidonecarboxylic acid but less than 1% of esterified glutamine. In extending the g.l.c. of amino acids, the previously unknown positions in the g.l.c. elution pattern of the following amino acids could also be reproducibly determined: carboxymethylcysteine, homoserine, hydroxylysine and ∈-methyl-lysine. Further, certain glycopeptides were investigated and the artifacts due to their carbohydrate moieties were determined.

Qualitative and quantitative determination of trace aldehydes and ketones in food preservative propionic acid for quality improvement

2021 ◽  
Author(s):  
Yiwen Cao ◽  
Shenjie Zhu ◽  
Lin Zhang ◽  
Qun Cui ◽  
Haiyan Wang
Keyword(s):  
Quality Improvement ◽  
Quantitative Analysis ◽  
Quantitative Determination ◽  
Propionic Acid ◽  
Qualitative And Quantitative Analysis ◽  
Food Preservative ◽  
Qualitative And Quantitative ◽  
Aldehydes And Ketones ◽  
Aldehyde Content

Aiming at the difficulty in qualitative and quantitative analysis of trace compositions in food preservative propionic acid, the trace compositions and the key components influencing the total aldehyde content in...

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