Photometric Titration with Photoelectric Spectrophotometer

A Method for Measuring Bacterial Pigments by the Use of the Spectrophotometer and the Photoelectric Colorimeter.

A photoelectric spectrophotometer suitable for the measurement of vitamin A by the antimony-trichloride reaction.

The measurement by visual methods of the fleeting blue colour of vitamin A in the antimony-trichloride reaction presents considerable difficulties which can be largely overcome by the use of photoelectric methods with corresponding increase in accuracy. The photoelectric spectrophotometer now described was constructed in I 941 when no comparable instrument of this type was commercially availabl...

Determination of polyhexamethylene biguanide hydrochloride using photometric colloidal titration with crystal violet as a color indicator.

A solution of polyhexamethylene biguanide hydrochloride (PHMB-HCl) was titrated with a standard solution of potassium poly(vinyl sulfate) (PVSK) using crystal violet (CV) as an photometric indicator cation. The end point was detected by a sharp absorbance change due to an abrupt decrease in the concentration of CV. A linear relationship between the concentration of PHMB-HCl and the end-point vo...

A Photoelectric Densitometer for Use with Suspensions

A device for quickly and accurately measuring the population density of a suspension of microorganisms, permitting the preparation of yeast suspensions of known density to within 1 per cent error, was constructed with two Visitron photoelectric cells, a single light of high intensity and a good Wheatstone bridge for balancing the currents from the two photoelectric cells. A large Pyrex milk cul...

Coulometric Titration with Electrogenerated Tin(II). Titration of Platinum(IV)