2—THE HOMOGENEOUS ACID HYDROLYSIS OF METHYL CELLULOSE Part I—DETERMINATION OF REACTION RATE BY, REDUCING GROUP MEASUREMENTS

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%.

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

Clinical Chemistry ◽

10.1093/clinchem/13.3.215 ◽

1967 ◽

Vol 13 (3) ◽

pp. 215-219 ◽

Cited By ~ 4

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.

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Reaction Rate Studies of the Acid Hydrolysis of Some Chromium(III) Complexes. XIII. Water Exchange of mer-Triamminetriaqua- and Amminepentaaquachromium(III). Kinetic cis Effect of Ammonia vs. Water.

Acta Chemica Scandinavica ◽

10.3891/acta.chem.scand.36a-0555 ◽

1982 ◽

Vol 36a ◽

pp. 555-561 ◽

Cited By ~ 3

Author(s):

L. Mønsted ◽

O. Mønsted ◽

Johan Springborg ◽

Ingeborg Persdotter ◽

Johan Weidlein ◽

...

Keyword(s):

Acid Hydrolysis ◽

Reaction Rate ◽

Water Exchange ◽

Hydrolysis Of

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Reaction Rate Studies of the Acid Hydrolysis of Some Chromium(III) Complexes. VII. The Acid Hydrolysis of Tetraaqua(1,2-ethanediamine)-, Tetraaqua(1,3-propanediamine)- and Tetraaqua(trans-1,2-cyclohexanediamine)chromium(III) Ions in Aqueous Perchloric Acid.

Acta Chemica Scandinavica ◽

10.3891/acta.chem.scand.30a-0599 ◽

1976 ◽

Vol 30a ◽

pp. 599-608 ◽

Cited By ~ 4

Author(s):

Lene Mønsted ◽

Arvid Carlsson ◽

Bernt Carnmalm ◽

Birgitta Dahlén ◽

Jouko Koskikallio

Keyword(s):

Acid Hydrolysis ◽

Perchloric Acid ◽

Reaction Rate ◽

Aqueous Perchloric Acid ◽

Hydrolysis Of

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HPTLC determination of diosgenin in fenugreek seeds

Acta Pharmaceutica ◽

10.2478/acph-2018-0002 ◽

2018 ◽

Vol 68 (1) ◽

pp. 97-107 ◽

Cited By ~ 2

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 %.

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