A Beleza da Química Analítica Qualitativa na Proposição de Esquemas de Separação e Identificação de Níquel em Bijuterias

Resumo

The Qualitative Analytical Chemistry discipline offers a great challenge in its teaching and learning
process. This work proposed schemes for cation separation and identification of nickel (Ni) in costume
jewelry (earrings). Nickel is a potentially toxic metal; its identification in samples D and P was based
on a chemical reaction that occurs between Ni²⁺ and dimethylglyoxime, with the formation of a red,
insoluble complex. The first stage of the analysis consisted of preparing the samples. Next, a procedure
based on the separation schemes for group III and/or group IV A cations was used. A cation separation
and Ni identification scheme was developed for each sample. Sample D contains copper in its chemical
composition, which may interfere with the identification of nickel; it was necessary to remove it in the
form of CuS. This work culminated in the production of teaching material for the Analytical Chemistry
Laboratory for use by teachers and students of Chemistry Courses and related areas at Higher Education
Institutions, allowing them to adopt a contextualized approach to the teaching and learning process, so
that practical classes can become more attractive and relevant for students, enhancing this process.