Hydrazones as analytical reagents: a review.

The 655 articles cited in this review cover developments in the fields of ultraviolet light absorption spectrometry and light absorption spectrometry during the period December 1977 through November 1979, primarily documented in Chemical Abstracts. An extensive section of the review is devoted to the chemical aspects involved in the development of suitable reagents, absorbing systems, and methods for spectrophotometric analysis. Principles associated with the measurement of ultraviolet and visible radiant energy as well as the instrumentation used for these measurements are reviewed in the section entitled, Physics. Spectrophotometric methods for the determination of metals and of certain organic compounds are tabulated with matrix material, method or reagent, and appropriate reference number from the bibliography being specified. (BLM)

Ultraviolet and Light Absorption Spectrometry

Monohalogenobenzoylhydrazones II. Synthesis and Study of Ti(IV) Complexes with Monochlorobenzoylhydrazones of 2-Furaldehyde, 2-Thiophenaldehyde, 2-Pyrrolaldehyde and Di-2-pyridylketone as Ligands

Micro-amounts of cobalt(II) were determined spectrophotometrically at 500 nm using a flow injection manifold and 2,2′-dipyridyl-2-pyridylhydrazone (DPPH) as a colour-forming reagent. The various chemical and physical variables were optimized and a study of interfering ions was also carried out. A linear calibration graph was obtained for 0–12.0 mg l–1 cobalt(II), at a sampling rate of 90 injections per hour. The accuracy and reproducibility were very good (sr= 0.4%), the limit of detection was 0.017 mg l–1 and the limit of quantitation was 0.031 mg l–1. The method was found to be adequately selective owing to the fact that the strongly acidic medium used prevented the formation of complexes of the reagent with other ions. The method has been successfully applied to the determination of cobalt in cyanocobalamin (vitamin B12).

G. Kounenis

Papers

A new reagent for the spectrophotometric microdetermination of cadmium

Zinc and cadmium complexes of 2,2′-dipyridyl-2-pyridylhydrazone as visual acid-base indicators