PURPOSE Measurement of intravaginal pH provides a reasonable assessment of vaginal health but is fraught with the potential for several sampling errors. The purposes of the study were to determine the variability of self-sampled vaginal pH among women using an inexpensive swab-based pH test compared with a clinician-obtained specimen, and variability of vaginal pH within 3 regions of the normal...

___________________________________________________________________________________________ Abstract In this work, equations describing the effect of pH on the electrophoretic behaviour are used to investigate migration of a series of polyprotic amphoteric peptide hormones between pH 2 and 12 in polybrenecoated capillaries. Polybrene (hexadimethrin bromide) is a polymer composed of quaternary a...

This study involves the determination of mucous histochemistry at various regions of the alimentary canal of the Scardinius erythrophtholmus using light microscopy. Histochemical analysis showed that the gastrointestinal mucous content included sulphate-esters and/or carboxylic [Alcian blue (AB) pH 2.5 +], glycogene and/or oxidable dioles [periodic acid/Schiff+ (PAS+)], neutral or acid-rich (PA...

The voltammetric oxidation of all deoxyribonucleic acid (DNA) monophosphate nucleotides is investigated for the first time over a wide pH range by differential pulse voltammetry with a glassy carbon electrode. Experimental conditions such as the electrode size, supporting electrolyte composition, and pH were optimized to obtain the best peak potential separation and higher currents. This enable...

BACKGROUND In this study, a RP - HPLC method was applied for determination of pKa value by using the dependence of the capacity factor (k) on the pH of the mobile phase for oxysophocarpine (OSP). FINDINGS The effect of the mobile phase composition on the ionization constant was studied by measuring the pKa value at different MeOH concentrations, ranging from 10 to 20% (v/v). Based on all pH -...

A set of indicator molecules was selected and applied to elaborate an NMR-based pH determination method, free of glass electrode errors in highly basic media. Accurate measurement of pH values and protonation constants was achieved by a successive build-up of overlapping, increasingly high pH solutions, using a collection of 8 compounds of appropriately incremented basicities. In order to verif...

a simple and sensitive extraction-fluorimetric method for the determination of mercury is reported. the method is based on the quantitative extractionof a ternary crown-mercury-rose bengal complex into chloroform at ph 10 followed by fluorimetric measurements at 580 nm. a linear working range from 0.05 to 2.00 mg/ml is obtained. the relative standard deviation for 1.0 mg/ml mercury is 3.5%. the...

in this study a new simple selective and sensitive spectrophotometric procedure for determination of fe(iii) is described. it is based on the formation of a colored complex between ferric iron and ethyl maltol, a strong and highly selective ligand for fe(iii). after mixing sample and reagent, and incubating at the room temperature, fe(iii)-ethyl maltol complex was extracted with different solve...

1. Acetylated chymotrypsinogen was prepared by the reaction of crystallized chymotrypsinogen with acetic anhydride at pH 6.7 and 4O, and purification of the product. End group analysis and Van Slyke amino nitrogen determination indicated that all the free Eand or-amino groups of the chymotrypsinogen molecule had been blocked by acetylation. 2. Activation of acetylated chymotrypsinogen by trypsi...

in the present study, a simple and sensitive extractive spectrophotometric method is described for determination of buspirone. the method is based on the reaction of buspirone and bromocresol green. the ion-pair complex was quantitatively extracted into chloroform at ph 2.3 followed by spectrophotometric determination at 415 nm. the complex was stable up to 2 days and obeyed beer's law over the...