Profile of Sedatives and Tranquilizers in Serum, as Measured by Gas-Liquid Chromatography

1971 ◽  
Vol 17 (3) ◽  
pp. 222-228 ◽  
Author(s):  
Henning F Proelss ◽  
Herman J Lohmann
Keyword(s):  
Liquid Chromatography ◽  
Solvent Extraction ◽  
Liquid Phase ◽  
Screening Method ◽  
Gas Liquid Chromatography ◽  
Basic Drugs ◽  
Ph Values ◽  
Preliminary Separation ◽  
Glass Columns ◽  
Neutral And Basic Drugs

Abstract We describe here a rapid and comprehensive screening method for 40 commonly used sedatives and tranquilizers with use of gas-liquid chromatography. Barbiturates, nonbarbiturate sedatives, and tranquilizers of the phenothiazine, benzodiazepine, and dibenzazepine type can be both identified and measured in serum. A simple solvent extraction at different pH values, with subsequent solvent partition, effects a preliminary separation into acid, neutral, and basic drugs. The three fractions are separated on two standard 180-cm glass columns: acid and neutral drugs with the liquid phase XE-60 (3.5%) and basic drugs with the liquid phase OV-17(3%). Sera from more than 50 patients have been analyzed by this technique, and the concentrations of several sedatives and tranquilizers are reported.

Determination of Amphetamine and Methylamphetamine by Gas-liquid Chromatography (Head Space)

1983 ◽  
Vol 2 (2) ◽  
pp. 391-393 ◽  
Author(s):  
D. Martinez ◽  
M.P. Gimenez
Keyword(s):  
Liquid Chromatography ◽  
Solvent Extraction ◽  
Liquid Phase ◽  
Gas Phase ◽  
Urine Sample ◽  
Urine Samples ◽  
Gas Liquid Chromatography ◽  
Flame Detection ◽  
Therapeutic Doses

1 A method for determining amphetamine and methylamphetamine in urine by gas-liquid chromatography is described. 2 Chromatography is performed on a 10% Apiezon L, 10% KOH column with alkali-flame detection (NPD). This method avoids the losses of these volatile substances which are known to occur when solvent extraction is used. An alkalinized urine sample (1 ml) is introduced into a sealed vial which is heated in a water bath at 70°C for 20 min. A 1 ml portion of the gas phase in equilibrium with the liquid phase is chromatographed. 3 Amphetamine and methylamphetamine can be detected and measured in urine samples after single therapeutic doses of the drugs.

scholarly journals Gas Chromatographic Determination of Traces of Accelerants in Physical Evidence

1972 ◽  
Vol 55 (4) ◽  
pp. 840-845 ◽  
Author(s):  
Charles R Midkiff ◽  
Willard D Washington
Keyword(s):  
Liquid Chromatography ◽  
Solvent Extraction ◽  
Vapor Phase ◽  
Selection Criteria ◽  
Chromatographic Determination ◽  
Operating Parameters ◽  
Gas Liquid Chromatography ◽  
Internal Standards ◽  
Physical Evidence

Techniques developed for use with gas-liquid chromatography for the examination of evidence collected at the scene of suspected arson fires and firebombings are discussed. Both solvent extraction and vapor phase examinations are employed. Internal standards are used for the identification of specific components in actual samples to allow confirmation of hydrocarbon type, e.g., gasoline and kerosene. Operating parameters and solvent selection criteria are included. Results obtained from known materials and residual hydrocarbons in actual samples are compared.

Collaborative Study of the Extraction of Plant Sterols from Adulterated Butter Oil Using a Digitonin-impregnated Celite Column

1970 ◽  
Vol 53 (3) ◽  
pp. 535-538
Author(s):  
Denis E Lacroix
Keyword(s):  
Liquid Chromatography ◽  
Vegetable Oil ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Screening Method ◽  
Rapid Screening ◽  
Gas Liquid Chromatography ◽  
Butter Oil ◽  
Average Coefficient ◽  
Rapid Screening Method

Abstract A rapid screening method for the analysis of the phytosterol, β-sitosterol, in butter oil adulterated with vegetable oil has been studied collaboratively. The sterols are removed from the adulterated butter oil by passing the sample through a digitonin-impregnated Celite 545 column, eluting the sterols with dimethyl sulfoxide, and analyzing the eluate for β-sitosterol by gas-liquid chromatography using a 3% JXR column. The average coefficient of variation for those samples containing more than 4 mg β-sitosterol/100 g adulterated butter oil is 12.6%. Therefore, β-sitosterol can be used as an index to qualitatively detect vegetable oil adulteration of butter oil.

THE SEPARATION OF SOME TERPENOID COMPOUNDS BY GAS–LIQUID CHROMATOGRAPHY

1960 ◽  
Vol 38 (5) ◽  
pp. 631-640 ◽  
Author(s):  
E. von Rudloff
Keyword(s):  
Liquid Chromatography ◽  
Polyethylene Glycol ◽  
Liquid Phase ◽  
Diatomaceous Earth ◽  
Solid Support ◽  
Gas Liquid Chromatography ◽  
Polyphenyl Ether ◽  
Liquid Phases ◽  
Degree Of Separation ◽  
Separation Of Mixtures

A study has been made of the degree of separation of mixtures of some terpene hydrocarbons, some of their oxygenated derivatives, two sesquiterpene alcohols, and three monophenols on a variety of columns. Temperature and sample size affected the degree of separation and the solid support Chromosorb W, a calcined diatomaceous earth, was found to combine the advantages of Celite and C-22 firebrick without causing decomposition of the sample at higher temperatures. When Craig polyesters were used as liquid phases, separations equal to those obtained on polyethylene glycol were realized with the added advantage that these produced columns which are stable at 190 to 220 °C. Consequently, sesquiterpene alcohols and monophenols were also separated successfully. Another useful liquid phase for both low and high temperatures was found in a meta-linked polyphenyl ether. Squalene was found to be an efficient liquid phase for the separation of terpene hydrocarbons at 130 °C and lower. The possible application of the present findings for preparative work is discussed.

Gas-Liquid Chromatography and Flame Photometric Detection of Phosphine in Wheat

1978 ◽  
Vol 61 (4) ◽  
pp. 829-836 ◽  
Author(s):  
Thomas W Nowicki
Keyword(s):  
Liquid Chromatography ◽  
Screening Method ◽  
Gas Liquid Chromatography ◽  
Gas Chromatograph ◽  
Aluminum Phosphide ◽  
Photometric Detection ◽  
Residual Aluminum ◽  
Flame Photometric Detection ◽  
Rubber Septa ◽  
Electronic Integrator

Abstract A screening method using gas-liquid chromatography with flame photometric detection has been developed for determining phosphine in wheat. Phosphine is measured as the sum of physically bound intact phosphine and that derived from residual aluminum phosphide. Wheat is extracted in a closed, partially evacuated glass system by refluxing with 10% sulfuric acid. Liberated gases are swept into a gas-collection flask fitted with rubber septa to permit gas sampling. Aliquots of collected gas are injected into a gas chromatograph. Phosphine is quantitated by peak area as determined by an electronic integrator. Recoveries varied with concentration: 67% was recovered at 0.10 ppm and 98% was recovered at 19 ppm. For concentrations less than 1.5 ppm, the coefficient of variation was 9.95%. Using flame photometric detection, phosphine concentrations as low as 0.04 ppm were easily determined in wheat.

Gas—Liquid Chromatographic Measurement of Guanidino Acids

1975 ◽  
Vol 21 (7) ◽  
pp. 838-843 ◽  
Author(s):  
Harini Patel ◽  
Burton D Cohen
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Liquid Chromatography ◽  
Liquid Phase ◽  
Magnetic Resonance ◽  
Gas Liquid Chromatography ◽  
Butyl Esters ◽  
Silicone Liquid ◽  
Chromatographic Measurement ◽  
Liquid Chromatographic

Abstract We present a method for separating and measuring guanidino acids by gas—liquid chromatography. Compared to ion-exchange techniques, this system is faster, more sensitive, requires smaller sample volumes, is independent of colorimetric reactions, and permits simultaneous determination of both amino and guanidino acids. N-Trifluoroacetyl-n-butyl esters are formed and then are separated by using a column containing a mixed silicone liquid phase coated on Chromosorb W-HP. Analytical recoveries from plasma ranged from 86 to 112% and were optimal when purification and derivatization were done without prior protein precipitation. Speculations as to the cause of this interference by protein include coprecipitation, protein-binding, and cyclization of the guanidines in the acids used for denaturation. Evidence presented suggests that all three occur: ultrafiltrability is diminished in the presence of protein and nuclear magnetic resonance demonstrates cyclization of some of these esters.

Optimum use of paper, thin-layer and gas-liquid chromatography for the identification of basic drugs

1974 ◽  
Vol 90 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Anthony Christopher Moffat ◽  
Kenneth Wallace Smalldon ◽  
Colin Brown
Keyword(s):  
Liquid Chromatography ◽  
Thin Layer ◽  
Gas Liquid Chromatography ◽  
Basic Drugs
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