DETERMINATION OF MICRO-AMOUNTS OF 5β-PREGNAN-3α-OL-20-ONE IN URINE USING INFRARED-SPECTROMETRY

1962 ◽  
Vol 41 (2) ◽  
pp. 234-246 ◽  
Author(s):  
H. J. van der Molen
Keyword(s):  
Infrared Spectrum ◽  
Quantitative Determination ◽  
Acid Hydrolysis ◽  
Chromatographic Separation ◽  
Pure Form ◽  
Infrared Spectrometry ◽  
Hydrolysis Of

ABSTRACT A procedure for the quantitative determination of 5β-pregnan-3α-ol-20-one in urine is described. After acid hydrolysis of the pregnanolone-conjugates in urine, the free steroids are extracted with toluene. Pregnanolone is isolated in a pure form as its acetate; after chromatographic separation of the free steroids on alumina, the fraction containing pregnanolone is acetylated and rechromatographed on alumina. Quantitative determination of the isolated pregnanolone-acetate is carried out with the aid of the infrared spectrum recorded by a micro KBr-wafermethod. The reliability of the method under various conditions is discussed under the headings, specificity, accuracy, precision and sensitivity. It is possible to determine 30–40 μg pregnanolone in a 24-hours urine portion with a precision of 25%.

The determination of acetone using mass spectrometry after acid hydrolysis of polymer acetals

1983 ◽  
Vol 48 (7) ◽  
pp. 2015-2020 ◽  
Author(s):  
Slavko Hudeček ◽  
Jaroslava Otoupalová ◽  
Miroslav Ryska ◽  
Jan Světlík ◽  
Pavel Čefelín
Keyword(s):  
Mass Spectrometry ◽  
Quantitative Determination ◽  
Methyl Methacrylate ◽  
Acid Hydrolysis ◽  
Internal Standard ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Hydrolysis Of

A mass spectrometric method for the determination of acetone in the presence of polymers has been suggested. Perdeuterated acetone was used as the internal standard. The method was employed in a quantitative determination of (2,2-dimethyl-1,3-dioxolane-4-yl) methyl methacrylate units in copolymers with methyl methacrylate and in the determination of copolymerization parameters.

Determination of Unconjugated and Total N-Acetyl-p-aminophenol (NAPA) in Urine and Serum

1967 ◽  
Vol 13 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Karel P M Heirwegh ◽  
Johan Fevery
Keyword(s):  
Liver Disease ◽  
Acid Hydrolysis ◽  
Azo Dye ◽  
Acidic Medium ◽  
Diazonium Salt ◽  
Accurate Method ◽  
Total N ◽  
Hydrolysis Of ◽  
Urine And Serum

Abstract A sensitive and accurate method is described for the determination of N-acetyl-p-aminophenol (NAPA) and its metabolites in urine and serum. In strongly acidic medium, p-aminophenol (PAP) resulting from differential extraction and acid hydrolysis of total NAPA and unconjugated NAPA, is diazotized and the diazonium salt coupled with N-(1-naphthyl)ethylenediamine (NED) in the presence of ethanol. The blue azo dye formed is determined spectrophotometrically. Application to liver disease is briefly reported.

scholarly journals HPTLC determination of diosgenin in fenugreek seeds

2018 ◽  
Vol 68 (1) ◽  
pp. 97-107 ◽  
Author(s):  
Barbara Król-Kogus ◽  
Khenifi Mohammed Lamine ◽  
Piotr Migas ◽  
Messaoud Boudjeniba ◽  
Mirosława Krauze-Baranowska
Keyword(s):  
Ethyl Acetate ◽  
Acid Hydrolysis ◽  
Methanolic Extract ◽  
Soxhlet Extraction ◽  
African Origin ◽  
Fenugreek Seeds ◽  
Hydrolysis Products ◽  
Hydrolysis Of

Abstract A new HPTLC-densitometric method for diosgenin determination in fenugreek seeds was established after optimization of the conditions for efficient saponin extraction and acid hydrolysis. Several procedures were tested, the best of which was a three-step Soxhlet extraction, followed by hydrolysis of the obtained methanolic extract with 2 mol L-1 H2SO4. Best diosgenin separation from other hydrolysis products was obtained on HPTLC Si60F254 plates u sing a mixture of n-heptane/ethyl acetate (7:3, V/V) and modified anisaldehyde as a spraying reagent. The method was preliminarily validated and the determined amounts of diosgenin in fenugreek seeds of Polish and African origin were found to be similar and ranged from 0.12-0.18 %.

Determination of Carbaryl Residues in Honey Bees

1965 ◽  
Vol 48 (4) ◽  
pp. 771-774
Author(s):  
D P Johnson ◽  
H A Stansbury
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Quantitative Determination ◽  
Honey Bees ◽  
Methylene Chloride ◽  
Hydrolysis Product ◽  
Separate Analysis ◽  
Yellow Substance ◽  
Hydrolysis Of

Abstract A method has been developed for detecting residues of carbaryl (1-naphthyl methylcarbamate) as well as its hydrolysis product, 1-naphthol, in dead bees. The method is based on extraction of the bees with benzene, followed by a cleanup involving liquid partitioning and chromatography on Florisil. The quantitative determination involves hydrolysis of carbaryl to 1-naphthol and coupling of the latter with p-nitrobenzenediazonium fluoborate in acetic acid to form a yellow substance. For separate analysis, free 1-naphthol is separated from methylene chloride into a basic aqueous solution. The sensitivity of the method is about 0.1 ppm; recoveries averaged 85.6 ± 6.6% for 1- naphthol and 83.8 ± 2.7% for carbaryl.

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