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 Spectrophotometric Determination of Bromhexine Hydrochloride in Its Pharmaceutical Preparations by Diazotization and Coupling Method

2020 ◽  
pp. 2172-2181
Author(s):  
Saad Hasani Sultan ◽  
Zainab Walid Majed
Keyword(s):  
Azo Dye ◽  
Acidic Medium ◽  
Diazonium Salt ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Water Soluble ◽  
Standard Methods ◽  
Alkali Medium

A simple, fast, and sensitive spectrophotometric method was suggested for the determination of Bromhexine Hydrochloride (BHH) in its pharmaceutical formulations. The method depends on the diazotization of BHH by sodium nitrite in acidic medium to produce the corresponding diazonium salt. The latter is coupled with phloroglucinol reagent in alkali medium to form a yellow water soluble azo-dye which has a maximum absorption at 405 nm with a molar absorptivity of 2.7×104 l.mol-1.cm-1 and Sandellʼs sensitivity of 0.01517 µg.cm-1. Beerʼs low is obeyed within a concentration range of 0.25-15 µg.mL-1 of BHH. The LOD and LOQ values of the proposed method were 0.087 µg.mL-1 and 0.293 µg.ml-1, respectively. The proposed method was validated with standard methods and successfully applied to the determination of Bromhexine in its pharmaceutical formulations as tablets, syrup, and injections.

Extraction Spectrophotometric Determination of [(2-Chlorophenyl)methylene]propane Dinitrile with Reactive Dyes of the Stabilized Diazonium Salt Type

1992 ◽  
Vol 57 (6) ◽  
pp. 1221-1229
Author(s):  
Emil Halámek ◽  
Zbyněk Kobliha
Keyword(s):  
Mass Spectrometry ◽  
Spectrophotometric Method ◽  
Azo Dye ◽  
Diazonium Salt ◽  
Reactive Dyes ◽  
Diazonium Salts ◽  
Fast Red ◽  
Hydrolysis Of ◽  
C Nmr

A spectrophotometric method has been developed for the determination of [(2-chlorophenyl)methylene]propane dinitrile (CS) stabilized by the diazonium salts Fast Red TR and Fast Blue B after extraction with chloroform. Mass spectrometry, 1H and 13C NMR and elemental analysis confirmed the presence of the hydrazoform of the azo dye formed by reaction with malononitrile, as a product of the alkaline hydrolysis of substance CS, and the diazonium salt Fast Red TR.

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%.

A simple procedure using trinitrobenzenesulphonic acid for monitoring proteolysis in cheese

1988 ◽  
Vol 55 (4) ◽  
pp. 585-596 ◽  
Author(s):  
Anna Polychroniadou
Keyword(s):  
Simple Procedure ◽  
Water Soluble ◽  
Acid Solutions ◽  
Amino Groups ◽  
Total N ◽  
Cheese Ripening ◽  
Amino Acid Solutions ◽  
Hydrolysis Of ◽  
Good Agreement

SummaryA simple, rapid and sensitive spectrophotometric assay was developed and evaluated for monitoring proteolysis during cheese ripening, based on the fact that α-amino groups released by hydrolysis of cheese proteins react with trinitrobenzenesulphonic acid to form products that absorb strongly at 420 nm. A linear relationship was shown to exist between A420 and concentration of free α amino groups up to 0·5 HIM (r = 0·999, 38 df, P < 0·001). Repeatability of the method was satisfactory. The coefficient of variance was 0·53% for amino acid solutions and 1·19% for cheese extracts. Average recovery of glycine added to the cheese was 104 ± 2·9%. A comparison of the above method with that of determination of water-soluble N to total N ratio showed that there was good agreement between these two methods of assessment of proteolysis in cheese (r = 0·857, 32 df, P < 0·001). Mainly Feta and Teleme cheese were examined, but a similar correlation was obtained with hard Greek cheeses. Analytical conditions of the procedure are discussed.

scholarly journals Spectrophotometric determination of metoclopramide hydrochloride in pharmaceutical tablets, by diazotization-coupling method with 1-naphthol as the coupling agent

2010 ◽  
Vol 7 (1) ◽  
pp. 704-712
Author(s):  
Baghdad Science Journal
Keyword(s):  
Detection Limit ◽  
Azo Dye ◽  
Diazonium Salt ◽  
Molar Absorptivity ◽  
British Pharmacopoeia ◽  
Pharmaceutical Tablets ◽  
Hydrochloric Acid Medium ◽  
Metoclopramide Hydrochloride ◽  
Sensitive Spectrophotometric Method

Simple, rapid and sensitive spectrophotometric method was proposed for the analysis of metoclopramide hydrochloride (MPH) in pure form as well as in pharmaceutical tablets. The method is based on the diazotization reaction of MPH with sodium nitrite in hydrochloric acid medium to form diazonium salt, which is coupled with 1-naphthol in sodium hydroxide medium to form azo dye, showing absorption maxima at 550 nm. Beer’s law is obeyed in the concentration range of 0.4 – 18 µg mL-1 of MPH with detection limit 0.5448 µg mL-1. The molar absorptivity and Sandell’s sensitivity are 3.4969 × 104 L mol-1 cm-1 and 0.0101 µg cm-2, respectively. The method was successfully applied to the determination of MPH in pharmaceutical tablets without any interference from common excipients used as additives in tablets. The results agree favorably with the official British Pharmacopoeia method.

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 %.

scholarly journals A New Generation of Glycoconjugated Azo Dyes Based on Aminosugars

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Lorenzo Guazzelli ◽  
Giorgio Catelani ◽  
Felicia D’Andrea
Keyword(s):  
Acid Hydrolysis ◽  
Azo Dyes ◽  
Azo Dye ◽  
Protecting Groups ◽  
Third Generation ◽  
Sugar Moiety ◽  
The Third ◽  
New Generation ◽  
Monoazo Dyes ◽  
Hydrolysis Of

The third generation of glycoconjugated azo dyes (GADs) was prepared linking monoazo dyes to 6-amino-6-deoxy-d-galactose or 6′amino-6′-deoxylactose through mixed amido-ester connections. The complementary conjugation reactions were studied using the succinyl derivative of either the acetal protected aminosugar or the azo dye. Target “naturalized” GADs were obtained after acid hydrolysis of the acetal protecting groups present on the sugar moiety.

Determination of 5-methylcytosine by acid hydrolysis of DNA with hydrofluoric acid

1987 ◽  
Vol 167 (2) ◽  
pp. 347-351 ◽  
Author(s):  
J. Catania ◽  
B.C. Keenan ◽  
G.P. Margison ◽  
D.S. Fairweather
Keyword(s):  
Acid Hydrolysis ◽  
Hydrofluoric Acid ◽  
Hydrolysis Of ◽  
Hydrolysis Of Dna
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