Several methods are available in literature for the determination of percentage purity of diazepam (pharmaceutical raw material) either by non aqueous titration or spectrophotometric methods. For the quantitative determination of diazepam from the commercial pharmaceutical preparations, the current official B.P method (nonaqueous titration and spectrophotometric assay) has been utilized and a c...

The most commonly used technique for water content determination is Karl-Fischer titration with electrometric detection, requiring specialized equipment. When appropriate equipment is not available, the method can be performed through visual detection of a titration endpoint, which does not enable an analysis of colored samples. Here, we developed a method with spectrophotometric detection of a...

Rat liver nuclei were separated into two fractions, the nucleolus and the nucleoplasm, by a combined salt-enzymic extraction. RNA was purified from both sources and analysed on sucrose density gradients. In both fractions a prominent heterogeneous RNA class with mean sedimentation coefficient of 18S was found. This material was analysed by measuring the rate of reaction with formaldehyde, the u...

Potentiometric and spectrophotometric titrations of staphylococcal enterotoxin B have been carried out in 0.16 M KC1 at 25”. Potentiometric titration results indicate that the titration curves are essentially reversible between pH 1.50 and 11.0. All of the ionizable groups in enterotoxin B found from the titration curves are consistent with the amino acid composition which has been reported in ...

Several researchers have proposed spectrophotometric modifications of the Winkler titrimetric method for measuring dissolved oxygen (DO). These modifications, although simple, are not widely used because of concern about accuracy, calibration, and possible sources of interference. Here we show, using natural samples from lakes and rivers as well as samples manipulated in the laboratory, that th...

the interaction of p-sulphonatocalix [6] arene towards l-arginine and l-lysine has been studied inacidic aqueous solution (p1-1 2) using uv-vis spectrophotometric titration technique. the psulphonatocalix[6] arene was found to be able to form 1:1 complexe with amino acids in water.the values of the association constant were determined at different temperatures to evaluate thethermodynamic funct...