A spectrophotometric method for determination of mesna (MA), 6-mercaptopurine (MP), 6-thioguanine (TG), and 6-propyl-2-thiouracil (PTU) has been developed. The method was based on the reaction of thiouracils with N,N-dimethyl-p-phenylenediamine (DMPD) in acidic solution in the presence of the Fe3+ ion, an oxidising agent. Absorbance of the obtained coloured products was measured at the correspo...

A heterogeneous catalyst containing manganese Schiff base complex (derived from 2,4-dihydroxybenzadehyde and 1,2-phenylenediamine) is produced by covalent anchoring in MCM-41 matrix. The synthesized catalyst was characterized by X-ray diffraction pattern (XRD), inductivity coupled plasma (ICP), Fourier transform infrared (FT-IR) spectroscopy, N2 sorbtion-desorbtion isotherm and by tr...

were performed according to the guidelines of the Spanish Contact Dermatitis Research Group (abbreviated in Spanish to GEIDAC) using the standard GEIDAC series and a rubber series (Chemotechnique, Malmö, Sweden). Readings at 48 and 96 hours were positive (++) for the carba mix, the thiuram mix, the black rubber mix, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, N-cyclohexylN-phe...

In this work, we studied the conditions of deposition of a semipermeable polyphenylenediamine (PPD)-based membrane on amperometric disk platinum electrodes. Restricting an access of interfering substances to the electrode surface, the membrane prevents their impact on the sensor operation. Two methods of membrane deposition by electropolymerization were compared-at varying potential (cyclic vol...

2-phosphonobutane-1,2,4-tricarboxylic acid is(pbtc) a member of phosphonate family, and used as corrosion and scale inhibitor in cooling water systems. phosphonocarboxylates as a member of organophosphorus compounds have c-p and p-o bonds in their structures. pbtc is mainly used as carbonate scale inhibitor (caco3), sulphate scale inhibitor (caso4), corrosion inhibitor of low alloyed steel, eff...

A series of aniline and m-phenylenediamine derivatives with electron-withdrawing 3,3,3-trifluoropropenyl substituents were synthesized as small and chemically stable fluorescent organic compounds. Their fluorescence performances were evaluated by converting 2,4-disubstituted aniline 1 to the non-fluorescent dipeptide analogue H-Gly-Pro-1 for the use as a fluorogenic substrate for dipeptidyl pep...

1. The rates of translocation of oxaloacetate and l-malate into rat liver mitochondria were measured by a direct spectrophotometric assay. 2. Penetration obeyed Michaelis-Menten kinetics, and apparent K(m) values were 40mum for oxaloacetate and 0.13mm for l-malate. 3. Arrhenius plots of the temperature-dependence of rates of penetration gave activation energies of +10kcal./mole for oxaloacetate...