SULPHINIC ACIDS AS ANALYTICAL REAGENTS

4H-1-Benzopyrans as Analytical Reagents - A Review

4H-1-benzopyrans and their derivatives have been used widely as analytical reagents for the spectrophotometric determination of several transition metal ions. The present article reviews the importance of 4H-1-benzopyrans as analytical or complexing or chelating agent and fundamental conditions of several methods used for analytical determination of metal ions spectrophotometrically. Received d...

Comparative Gas Chromatography of Halides Using Different Substituted Phenylboronic Acids as Derivatizing Reagents

The GC of halides (chloride, bromide and iodide) using phenylboronic acid (PBA), 4-bromophenylboronic acid (BPBA), 3, 5 bis (trifluoromethyl) phenylboronic acid (FPBA) and 2,4- dichlorophenylboronic acid (CPBA) as derivatizing reagents are compared. The reactions are carried out in the presence of mercuric salts. The detection systems used are FID and ECD. The thermal analysis of the compou...

Prenyl sulfates as alkylating reagents for mercapto amino acids.

A new methodology for prenylation of thiol compounds has been developed. The approach is based on the use of prenyl sulfates as new reagents for S-prenylation of benzenethiol and cysteamine in aqueous systems. The C(10)-prenols geraniol and nerol that differ in the configuration (E or Z, correspondingly) of the alpha-isoprene unit were efficiently O-sulfated in the presence of a pyridine-SO(3')...

Pyridoxal phosphate as the coenzyme of the mammalian decarboxylase for L-cysteine sulphinic and L-cysteic acids.

Simple spectrophotometric methods for quantification of modafinil using 1,2-naphthoquinone-4-sulphonate and 2,4-dinitrophenol as analytical reagents

Two simple visible spectrophotometric methods are developed and validated for the quantification of modafinil using 1,2-naphthoquinone-4-sulphonic acid (NQS method) and 2,4-dinitrophenol (DNP method) as analytical reagents. The NQS method involves the reaction of modafinil with 1,2-naphthoquinone-4-sulphonate in alkaline medium at room conditions to form a yellow colored product exhibiting maxi...