Colorimetry in Chemical Analysis
Colorimetric Methods of AnalysisIncluding Some Turbidimetric and Nephelometric Methods. By Dr. Foster Dee Snell. Dr. Cornelia T. Snell. Third edition. Vol. 2: Inorganic. Pp. x + 950. (New York: D. Van Nostrand Co., Inc.; London: Macmillan and Co., Ltd., 1949.) 90s. net.
Colorimetric Estimation of Silver
IN some current work using evaporated metal films, it became necessary to estimate small quantities of silver of about 2 × 10−5 gm. The method developed by Schoonover1 and quoted by Welcher2, the “B.D.H. Book of Organic Reagents” and others, seemed suitable. Preliminary experiments, however, indicated that the method was unreliable. The purpose of this note is to present some typical results of a subsequent series of experiments which show the unsatisfactory nature of the method.
A colorimetric method for the quantitative determination of small amounts of silver by use of p-dimethylaminobenzalrhodanine
Recent interest in the use of Rilver as a bacteri cidal agent led to the study of analytical methods suita ble for det erminin g silver in the small concentrations employed for these purposes. A sensitive and accurate colorimetric method, in which p-dimethylaminobenzalrhodanine is used, was developed. Soft-glass dishes are not, suitable for use in the analyti cal procedure because of a yery pronounced adsorption of silver on such surfaces. Dishes of fu sed silica or of Pyrex glass were satisfactory. Chlorirles, sulfates, and cupr us and mercurous salts interfere with this colorimetric determinatio n. CONTENTS Page