The study is to measure the serum concentration of ascorbic acid in pregnant women during all the trimesters. Methods: Total serum concentration was measured using the 2,4-Dinitrophenylhydrazine method, which involves the conversion of vitamin C to dehydroascorbic acid in the presence of copper ions and subsequent measurement of the resulting bishydrazone at 540nm. Results revealed that total v...

0x0 compounds (2,4-dinitrophenylhydrazine-reactive) formed during the Maillard reaction between glucose and glycine were converted into 2,4_dinitrophenylhydrazones and were separated into five main fractions by reversed-phase chromatography on Separon SGX Cl8 using a methanol-water gradient. Four of these fractions were homogeneous, as shown by thin-layer chromatography. One of the fractions st...

A spectrophotometric method was developed for the determination of methyldopa. The is based on oxidative coupling reactions with 4,2-dinitrophenylhydrazine as a reagent and in presence oxidizing agent potassium periodate acidic medium. product exhibits maximum absorption at 428 nm, Beer's law-subjective concentration range (1-30) µg/ml, molar absorbance 6589,908 liters. mol-1.cm-1. relative sta...

Rapid, sensitive and simple spectrophotometric method for the determination of oxymetazoline hydrochloride (OXMZ) is developed. The based on an oxidative coupling reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH) in a basic medium (pH 11.2) presence potassium periodate to produce green colour, soluble water , stable product absorbs at 607 nm. Beer's law was linear range 2.5-30 μg/ml OXMZ, mol...

Two vanillin-hydrazone compounds as the colorimetric amine detection during chicken meat spoilage are described. hydrazone (1 and 2) have been synthesized from condensation reaction of vanillin with phenylhydrazine 2,4-dinitrophenylhydrazine. Their properties for recognition were determined by naked eye UV-vis spectra. indicators investigated toward primary amine: butylamine (BA); secondary dim...

Low levels of thermal degradation products such as carbonyls (formaldehyde, acetaldehyde, acrolein, crotonaldehyde) have been reported in e-cigarette aerosols. The collection and analysis of e-cigarette aerosol carbonyls are often adapted from methods developed for tobacco cigarette smoke. These methodologies are often not sensitive enough to detect low carbonyl levels in e-cigarette aerosols. ...

d(-) Lactate oxidation in Azobacter vinelandii strain O is readily carried out by the membrane bound enzyme that concentrates in the electron transport fraction (R(3)). This oxidation in the R(3) fraction is not dependent on externally added nicotinamide adenine dinucleotide, flavine adenine dinucleotide, or flavine mononucleotide. Phenazine methosulfate, O(2), and menadione all served as good ...