DETERMINATION OF PLASMA OESTRIOL IN NORMAL PREGNANCY AND LABOUR USING GAS-LIQUID CHROMATOGRAPHY

1971 ◽  
Vol 51 (3) ◽  
pp. 447-454 ◽  
Author(s):  
W. COOPER ◽  
M. G. COYLE ◽  
J. A. MILLS
Keyword(s):  
Gas Chromatography ◽  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Internal Standard ◽  
Normal Pregnancy ◽  
Gas Liquid Chromatography ◽  
Chemical Purification ◽  
Peripheral Plasma ◽  
Pregnancy And Delivery

SUMMARY A method is described for estimating oestriol in 2–10 ml samples of human pregnancy peripheral plasma. It incorporates acid hydrolysis, chemical purification, methylation, chromatography on alumina columns, formation of a derivative and quantitative determination by gas chromatography. A radioactive internal standard was added to correct for procedural losses. Plasma oestriol determinations in five normal patients throughout pregnancy and delivery are reported.

Separation of Vitamins D2 and D3 as Isotachysterols D2 and D3 by Gas-Liquid Chromatography

1968 ◽  
Vol 51 (4) ◽  
pp. 834-838
Author(s):  
A J Sheppard ◽  
Denis E Lacroix ◽  
A R Prosser
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Infrared Absorption ◽  
Quantitative Measurement ◽  
Acetyl Chloride ◽  
Internal Standard ◽  
The Other ◽  
Gas Liquid Chromatography ◽  
Absorption Data

Abstract A method for the quantitative determination of 0.5—20 μg vitamins D2 and D3 by gas-liquid chromatography is described. Vitamins D2 and D3 are completely isomerized to their respective isotachysterol isomers by acetyl chloride as demonstrated by ultraviolet and infrared absorption data. Dihydrotachysterol D2, isotachysterol D2, and isotachysterol D3 are completely resolved with a 3% JXR on 100-120 mesh Gas Chrom Q column packing. Calibration studies show that each compound exhibited a characteristic dose-response plot. Therefore, one isomer cannot be used as a direct internal standard for the quantitative measurement of the other isomer.

Collaborative Study of Gas-Liquid Chromatographic Determination of Methaqualone in Pharmaceutical and Clandestine Preparations

1977 ◽  
Vol 60 (4) ◽  
pp. 935-939 ◽  
Author(s):  
Harold F Hanel
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Coefficients Of Variation ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Eight laboratories collaboratively studied a procedure for the quantitative determination of methaqualone. HCl in pharmaceutical and clandestine preparations. Methaqualone is extracted from an aqueous bicarbonate solution into chloroform and quantitated by gas-liquid chromatography on a 3% OV-1 column. Tetraphenylethylene is used as an internal standard. Two commercial preparations and 4 sample mixtures prepared by the author were studied. Recoveries for the 4 prepared samples ranged from 100.0 to 102.6%, and the coefficients of variation ranged from 1.58 to 4.15% for the 6 samples studied. The method has been adopted as official first action.

Mass Spectral Quantitation of Cocaine HCl in Powders

1981 ◽  
Vol 64 (4) ◽  
pp. 884-888
Author(s):  
Charles C Clark
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Mass Spectrometer ◽  
Internal Standard ◽  
Gas Liquid Chromatography ◽  
Relative Deviation ◽  
Mass Spectral ◽  
Hcl Concentration

Abstract Gas-liquid chromatography (GLC) using a mass spectrometer (MS) as a detector is used for the quantitative determination of cocaine HCl in powders. After the sample is dissolved in methanol containing deuterated cocaine HCl internal standard, an aliquot is injected into the GLC-MS system with the mass spectrometer operating in the scan mode. The cocaine HCl concentration is calculated from the 303/308 m/e ratio. The procedure has a relative deviation of approximately 2.3% and is applicable to samples containing a wide variety of diluents and adulterants.

Rapid Identification and Quantitative Determination of Barbiturates and Glutethimide in Blood by Gas—Liquid Chromatography

1971 ◽  
Vol 17 (7) ◽  
pp. 587-591 ◽  
Author(s):  
Joseph MacGee
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Whole Blood ◽  
Small Volume ◽  
Internal Standard ◽  
Rapid Identification ◽  
Gas Liquid Chromatography ◽  
Gas Chromatograph ◽  
Tetraethylammonium Hydroxide

Abstract Barbiturates and glutethimide can be identified and measured in whole blood, plasma, or serum in 20 min. An internal standard containing known amounts of five common barbiturates is added to the sample, the sample is acidified, and the sedatives are extracted rapidly into toluene, then from the toluene into a small volume of aqueous tetraethylammonium hydroxide. An aliquot of this last extract is introduced directly into the gas chromatograph, where the barbiturates are converted to their ethyl derivatives and separated on a silicone column. They are identified by observing which of the internal standard peaks has increased and measured by measuring the extent of increase. Glutethimide can be determined on the same chromatogram. Mephobarbital and phenobarbital can be simultaneously determined.

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