“S INTRODUCTION The concentration of sodium metabisulfite (Na2S2O5) in an ECP-2 bleach accelerator sample is determined by a manual or potentiometric titration using an iodine (I3) titrant. In the method an excess of iodine is added to the sample. Sodium metabisulfite and Kodak persulfate bleach accelerator, PBA-1, present in the sample react with a portion of the iodine. The iodine that did no...

The enzymatic activity of the mitochondrial oligomycin-sensitive ATPase was investigated during isoproterenol-induced cell injury of myocardium, using rat heart homogenates and a potentiometric method. The enzymatic activity of the oligomycin-sensitive ATPase and the inhibitory action of oligomycin do not show significant alterations upon treatment with isoproterenol. These results are inconsis...

The dynamic behaviour of the potentiometric carbon dioxide electrode is predicted by means of a digital simulation that considers both diffusion and reaction kinetics. The method allows for complete description of the electrode response without requiring the assumption that one of these processes can be neglected. The validity of the simulation was tested experimentally by using a commercial pC...

A plasticized Cr3+ ion sensor by incorporating 2,3,8,9-tetraphenyl-1,4,7,10-tetraazacyclododeca-1,3,7,9-tetraene (TTCT) ionophore exhibits a good potentiometric response for Cr3+ over a wide concentration range (1.0 x 10(-6)-1.0 x 10(-1) M) with a slope of 19.5 mV per decade. The sensor response is stable for at least three months. Good selectivity for Cr3+ in comparison with alkali, alkaline e...

The interactions of Zn(ll) ions with the blocked hexapeptide models -TESHHK-, -TASHHK- and -TEAHHK- of the -ESHH- motif of the C-terminal of historic H2A were studied by using potentiometric and IH-NMR techniques. The first step of these studies was to compare the pKa values of the two His residues inside each hexapeptide calculated by potentiometric or H-NMR titrations. Hereafter, the potentio...