Use of 4-(5-Br-2 pyridylazo)-1,3-diaminobenzene (5-Br-PADAB) for the spectrometric determination of cobalt in wine.

摘要

The typically low content of cobalt in wines hinders its quantification by molecular absorptiometry and atomic absorption spectrometry (AAS); difficulties arise both in the preparation of samples and cobalt detection. This work proposes a highly sensitive and selective extraction-spectrometry method that uses 4-(5-Br-2 pyridylazo)-1,3-diaminobenzene (5-Br-PADAB) for the determination of cobalt in this medium. Its accuracy and reproducibility are comparable to those of flame AAS. The molar absorptivity of the complex was 116 000 L mol-1 cm-1. Interference from Fe (III) and Cu (II) ions was resolved by masking them with fluoride and cupron respectively.