DETERMINATION OF MICRO QUANTITIES OF ANDROSTERONE, AETIOCHOLANOLONE AND DEHYDROEPIANDROSTERONE BY GAS-LIQUID CHROMATOGRAPHY

1964 ◽  
Vol 45 (4_Suppl) ◽  
pp. S71-S80 ◽  
Author(s):  
John T. France ◽  
Neal L. McNiven ◽  
Ralph I. Dorfman
Keyword(s):  
Stainless Steel ◽  
Liquid Chromatography ◽  
Trimethylsilyl Ether ◽  
Nitrogen Pressure ◽  
Gas Liquid Chromatography ◽  
Column Temperature ◽  
Steel Column ◽  
Stainless Steel Column ◽  
Reproducible Method

ABSTRACT A convenient, sensitive and reproducible method for the determination of androsterone, aetiocholanolone and dehydroepiandrosterone, as their trimethylsilyl ether derivatives, has been described. The conditions include: 3.3 % XE-60 on Anakrom ABS (90-100 mesh), 6 ft. × 3.8 mm i. d. stainless steel column, 225° column temperature, 327° vaporizer temperature, nitrogen pressure 11.0 p. s. i. (34 ml/min flow). The % variation between duplicate samples for androsterone, aetiocholanolone and dehydroepiandrosterone respectively was 1.5, 4.5 and 1.8 at the 0.3 μg level. Quantitation at the 0.05 μg level appears possible.

Gas-Liquid Chromatographic Determination of Chloroform in Toothpastes, Using the Headspace Analytical Technique

1974 ◽  
Vol 57 (3) ◽  
pp. 560-562
Author(s):  
Martin J Stutsman
Keyword(s):  
Stainless Steel ◽  
Liquid Chromatography ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Analytical Technique ◽  
Steel Column ◽  
Stainless Steel Column ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Chloroform in toothpastes is determined by gas-liquid chromatography of the vapors in the headspace over a diluted sample, using an electron capture detector. The method is sensitive to small amounts of chloroform and avoids the injection of materials deleterious to the column. The 12' × 1/8" od stainless steel column is packed with acid-washed Gas-Chrom R coated with 2 0% Carbowax 20M. Recoveries of chloroform added to toothpastes range from 95 to 104%.

Gas Chromatographic Determination of Pyrrolidonecarboxylic Acid

1970 ◽  
Vol 53 (4) ◽  
pp. 716-719
Author(s):  
C Y Lee
Keyword(s):  
Stainless Steel ◽  
Analytical Method ◽  
Chromatographic Determination ◽  
Gas Liquid Chromatography ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Extraction Apparatus ◽  
Steel Column ◽  
Stainless Steel Column

Abstract An analytical method is described for analysis of 2-pyrroIidone-5-carboxylic acid (PCA) in foods. PCA was extracted with ethyl acetate, using a modified Widmark extraction apparatus, and then silylated with trimethylchlorosilane and hexamethyldisilazane in the presence of pyridine. The trimethylsilylated PCA derivative was separated by gas-liquid chromatography on a 6′ × 1/4″ °d stainless steel column of 3% SE-30 on Gas Chrom Q and detected with a flame ionization detector. Recovery of PCA was 94-108%. This procedure is a relatively simple and rapid analytical method as compared to the conventional methods.

Gas-Liquid Chromatography of Trichlorfon in Soluble Powder Formulations

1974 ◽  
Vol 57 (5) ◽  
pp. 1128-1131
Author(s):  
Phil B Bowman ◽  
Peter W Dame
Keyword(s):  
Liquid Chromatography ◽  
Standard Deviation ◽  
Relative Standard Deviation ◽  
Trimethylsilyl Ether ◽  
Gas Liquid Chromatography ◽  
Mass Spectral ◽  
Powder Formulation ◽  
Relative Standard ◽  
Quantitative Recovery

Abstract A procedure is described for the determination of trichlorfon in a soluble powder formulation by gas-liquid chromatography. Silylation prevents on-column degradation of trichlorfon to dichlorvos. The procedure provides quantitative recovery from the formulation as demonstrated by a spiking study. A relative standard deviation of less than 2% was obtained for 6 replicate assays of a single lot of formulation. The mass spectral fragmentations of trichlorfon and trichlorfon-trimethylsilyl ether are described.

A method for serum octanoate in hepatic cirrhosis and hepatic encephalopathy.

1977 ◽  
Vol 23 (12) ◽  
pp. 2202-2206 ◽  
Author(s):  
J L Rabinowitz ◽  
J Staeffen ◽  
P Aumonier ◽  
P Ballan ◽  
J Ferrer ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Hepatic Cirrhosis ◽  
Venous Blood ◽  
Gas Liquid Chromatography ◽  
Ethanol Extraction ◽  
Reproducible Method ◽  
Cirrhotic Patients ◽  
Alkali Addition

Abstract We describe a new, more efficient, and more reproducible method for determination of octanoate in serum. This method involves ethanol extraction, followed immediately by alkali addition before concentration of the extract. The concentrate is made acidic only before it is to be steam distilled (in a special all-glass apparatus with an alkali trap). The material is acidified again just before separation by gas-liquid chromatography. The yield is 89-107%. When assayed by mass spectrometry, only octanoate was found in the fraction from chromatography. Previous methods yielded only 30-55% of the expected octanoate value and the recovered materials showed impurities by mass spectrometry. Octanoate concentrations were determined in the serum of 24 fasting controls and that of 85 fasting cirrhotic patients, of whom 50 had encephalopathy. Concentrations in arterial and venous blood were significantly higher in cirrhotic patients in coma than in those not in coma, and arterial concentrations were statistically higher than venous concentrations in the cirrhotic patients.

Serum estradiol-17 beta as determined by mass fragmentography and by radioimmunoassay.

1978 ◽  
Vol 24 (4) ◽  
pp. 627-630 ◽  
Author(s):  
J Zamecnik ◽  
D T Armstrong ◽  
K Green
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Trimethylsilyl Ether ◽  
Gas Liquid Chromatography ◽  
Mass Fragmentography ◽  
Serum Estradiol ◽  
Liquid Chromatography Mass Spectrometry ◽  
Serum Samples

Abstract We describe the preparation of [2,4,16,16-2H4]estradiol-17 beta. The method for quantitative determination of subpicomole amounts of estradiol-17 beta (trimethylsilyl ether derivatives) by gas-liquid chromatography-mass spectrometry with multiple ion detector and with [2H4]estradiol-17 beta as the carrier is presented and characterized. Values for serum samples, as measured by radioimmunoassay and by mass fragmentography, agreed well.

GASCHROMATOGRAPHIC DETERMINATION OF STEROIDS IN THE URINE OF PATIENTS WITH CUSHING'S SYNDROME

1971 ◽  
Vol 67 (2) ◽  
pp. 303-315 ◽  
Author(s):  
A. J. Moolenaar ◽  
A. P. van Seters
Keyword(s):  
Liquid Chromatography ◽  
Cushing’S Syndrome ◽  
Normal Subjects ◽  
Diagnostic Value ◽  
Cushing's Syndrome ◽  
Gas Liquid Chromatography ◽  
Obese Subjects

ABSTRACT The 17-oxosteroids were estimated in the urine of 27 patients with Cushing's syndrome by gas-liquid chromatography (G. L. C.). The values of the various steroid fractions are compared with those of normal subjects, patients with thyrotoxicosis and obese subjects. The effect of the age of the patients on the diagnostic value of the invidual 17-oxosteroids and their ratios is discussed.

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