Lead determination in commercial juice samples by direct magnetic sorbent sampling flame atomic absorption spectrometry (DMSS-FAAS)

The direct magnetic sorbent sampling flame atomic absorption spectrometry (DMSS-FAAS), recently proposed by our research group, was applied to determine the lead in soy-based juice, whole grape juice, reconstituted grape juice, and orange nectar samples. A dispersive solid phase extraction (d-SPE) of lead was carried out using a magnetic orange peel powder, developed and optimized by Gupta et al (2012), that was inserted into flame by FAAS with a magnetic probe. The limits of quantification (<4.6 mu g L-1) were smaller than maximum residue limits established in Brazil. Good precisions and accuracies were obtained. DMSS-FAAS presented a sensitivity at least 14 times greater than the d-SPE followed by conventional FAAS analysis, wherein the analytes were extracted and desorbed, and the eluate was introduced in FAAS via nebulization system. Lead was easily quantified in juice samples at very low concentrations, with satisfactory figures of merit, and without the need of a mineralization step.

Automated summary

The direct magnetic sorbent sampling flame atomic absorption spectrometry (DMSS-FAAS) was used to determine the lead levels in soy-based juice, whole grape juice, reconstituted grape juice, and orange nectar samples. Lead was extracted using a magnetic orange peel powder through dispersive solid phase extraction (d-SPE), and the analysis was performed using a magnetic probe in flame atomic absorption spectrometry (FAAS). The DMSS-FAAS method showed a sensitivity at least 14 times higher than the conventional d-SPE followed by FAAS analysis, allowing for easy quantification of lead in juice samples at very low concentrations without the need for mineralization.