This study aimed to determine cadmium in low-cost jewelry from China. In the qualitative test the sulfide was used as precipitating agent. Due to the strong interference of copper in qualitative analysis, this element was removed by chemical reaction or electrolysis. This removal was of paramount importance for the qualitative analysis of Cd2+. Quantification of Cd2+ was performed by means of atomic absorption spectrometry. The concentration of Cd was ~ 30% (w/w) in one of the pieces. It is noteworthy that in a small universe of low-cost jewelry analyzed (four samples), such a high cadmium content found in one of them leads us to think that jewelry containing Cd are widespread among citizens. This work can be useful to approach the case study method for teaching Analytical Chemistry at the undergraduate level.

In this study pequi (Caryocar brasiliense) shells were evaluated in relation to their potential for the adsorption of PbII ions in aqueous systems. The adsorbent was characterized by point of zero charge (PZC), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and PbII ions were detected by flame atomic absorption spectrometry (FAAS). The adsorption parameters studied were solution pH, adsorbent mass, contact time and the optimum adsorption conditions were found to be 7.0, 50 mg and 30 min, respectively, using 15 mL of the metal solution. A study on the adsorption kinetics and isotherms was performed applying the optimized conditions. The adsorption process followed a pseudo-second-order model. The experimental adsorption data were fitted to the Langmuir and Freundlich isotherm adsorptions and a very good fit to the Langmuir linear model was observed. The maximum adsorption capacity was found to be 35.52 mg g-1.