Complexes obtained from the electrostatic interactions between chitosan, a cationic polysaccharide, and sodium decylsulfonate, an anionic surfactant, were characterized by their conductimetric and surface-active properties. Such surfactant/polyelectrolyte complexes (SPECs) present very interesting surface-active properties, even at very low surfactant concentrations (much lower than the critica...

Coordination compounds of 5-chloroacetamido-1,3,4-thiadiazole-2-sulfonamide (Hcaz) with V(IV), Cr(lll), Fe(ll), Co(ll), Ni(ll) and Cu(ll) have been prepared and characterized by standard procedures (spectroscopic, magnetic, EPR, thermogravimetric and conductimetric measurements). Some of these compounds showed very good in vitro inhibitory properties against three physiologically relevant carbo...

A simple and economical minibioreactor-gas collector system for determination of hydrogen sulfide produced by a microorganism was designed. The detection of hydrogen sulfide was based on the reaction between the hydrogen sulfide in the gas stream from the culture, and a lead acetate solution 0.090 mol/L, contained in a tube gas collector; the conductimetric back titration of lead excess was mad...

published for the determination of lactate using liquid chromatography. One method (1) involves reverse-phase separation with a phosphate buffer at pH 3 as the mobile phase. Following the separation, the lactate is converted to hydrogen peroxide by a lactate oxidase IMER and then detected amperometrically. The optimal pH for the enzyme lactate oxidase is around 7, and at pH 3 the enzyme is basi...