Neal L. McNiven

Gas chromatographic determination of testosterone in human urine

Abstract A method has been developed for the analysis of testosterone in human urine. One tenth of a 24 hour urine sample was incubated with β-glucuronidase, and extracted with ethyl ether, the ketonic neutral fraction was subjected to thin layer chromatography and the eluted testosterone zone was analyzed gas chromatographically employing a stainless steel column containing 6.8% SE-30 Anakrom ABS (110–120) mesh and a flame ionization detector. Testosterone at the level of 15 μg per 24 hour sample or more could be determined with an error of ± 7.0 per cent (P = 0.99). The limits of uncertainty for the retention time of testosterone was ± 1.3% (P = 0.99).

A method for the determination of pregnanediol, pregnanetriol and pregnanetriolone by gas chromatography.

Abstract A method using gas-liquid chromatography (GLC) has been devised for the routine determination of urinary pregnanediol, pregnanetriol and pregnanetriolone. The procedure involves β-glucuronidase hydrolysis, extraction, thin-layer chromatography on alumina and finally quantitation as the trimethyl-silylather derivatives by GLC. using this technique quantities below 20 μg/24 hours can be determined. The method has been applied to the measurement of urinary levels of these steroids in normal and abnormal subjects.

Determination of Nicotine in Smokers' Urine by Gas Chromatography

THE highly controversial subject of the effects of smoking on health has been extensively investigated and reviewed in recent years1,2. It has been reported that nicotine has an effect on the cardiovascular system. However, its relation to coronary disease is not fully understood. The absorption of nicotine as the result of smoking is dependent on a number of factors3. The quantitation of nicotine and its metabolites in the body fluids of smokers would be helpful for the investigation of the relation between nicotine exposure and heart disease. It should also give a more reliable estimate of the quantities of other tobacco smoke ingredients to which the body is exposed. This communication describes such a method.

Identification of Testosterone Siilfate in Urine of Normal Adult Subjects.

Summary Testosterone sulfate was identified and quantitated in normal adult male urine. The method used involved a selective hydrolysis, thin-layer and paper chromatogra-phy followed by quantitation by gas chroma-tography. Values obtained were in the range of 5 to 10 micrograms per 24 hours.

Determination of isocaproic acid and isocaproic aldehyde in incubation media using gas chromatography

Abstract A gas Chromatographic method for the detection, separation and estimation of 0.030 μg of isocaproic acid and isocaproic aldehyde is described. Isocaproic acid resulting from the conversion of cholesterol incubated with a soluble enzyme system prepared from bovine corpus luteum was detected and quantitated. Under these conditions isocaproic aldehyde could not be detected due to loss by evaporation or rapid oxidation to the acid during incubation or both. Steroid hormone biosynthesis involves, in part, the hydroxylation of cholesterol at positions 20α and 22ξ followed by cleavage of the dihydroxy derivative to pregnenolone and isocaproic aldehyde 4–12 The isocaproic aldehyde may be farther oxidized to isocaproic acid 6–10 . Micromethods for the quantitative determination of these constituents are highly desirable for the detailed study of these reactions, and this communication presents a method using gas chromatography to satisfy the need.

Simple Slit Servomechanism for the Rudolph Spectropolarimeter

The Rudolph spectropolarimeter (model 656) in our laboratories is equipped with a dual monochromator containing entrance, intermediate, and exit slits.