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This work presents a study involving the determination of Cd, Cr and Pb in ceramic tableware by graphite furnace atomic absorption spectrometry (GF AAS) using a simple and practical slurry sampling method. A central composite design (CCD) was used to optimize the slurry sampling conditions. The obtained results were confronted by the ultrasonic acid decomposition, evaluating the instrumental parameters relevant to the accuracy and precision. In addition, recovery measurements of the analytes were performed and ranged between 90% and 111% for both methods. The concentrations obtained were in the range from 0.04 to 184; 67 to 1395 and 42 to 5305 μg g−1 for Cd, Cr and Pb, respectively. These concentrations were higher for some ceramic samples, which may be related to the raw material used for their manufacture and also due to the pigment used during the decoration process. In addition, the leaching study observed concentrations in the range from 0.07 to 1.68; 0.1 to 5.0 and 0.6 to 46.3 μg g-1 for Cd, Cr and Pb, respectively, and there is a possibility of migration of these toxic metals from the ceramic materials to the food. [ABSTRACT FROM AUTHOR]

[Display omitted] • Use of LIBS and MIP OES techniques for analysis ceramic tableware samples. • Determination of Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Pb, Ti and Zn. • Analysis of Brazilian and imported ceramic tableware. • Samples preparation by ultrasonic acid decomposition method. • Separation between groups of samples by PCA. In the present study, the microwave induced plasma optical emission spectrometry (MIP OES) and laser-induced breakdown spectroscopy (LIBS) complementary techniques are used to determine and locate metals in ceramic tableware samples. For quantitative analysis by MIP OES, a new method for sample treatment is proposed, preparing the samples using ultrasonic decomposition aided by an acid mixture containing HNO 3 and HF. The highest average concentrations were found in the group of Brazilian samples for most of the analytes. The accuracy of the quantitative method was assessed by comparing the results with two methods described in the literature. No significant differences were detected. Aiming at qualitative analysis and analyte locating by LIBS, a sample fragment was already sufficient for the analysis, being possible to observe that Al, Ba, Ca, Fe, K, Li, Mg, Na and Ti are present in the ceramic mass and decorated surface, while Cd, Co, Cr, Cu, Mn, Pb and Zn are found only on the sample surface. Besides, according to LIBS results, it would be essential to pay attention to pigmentation, which contains most of the potentially toxic elements, at locations in direct contact with food to minimize the risk of leaching and avoid human contamination. This study shows that MIP OES and LIBS can be used complementarily to improve the analytical information used to control the ceramic tableware quality and safety. The conclusions of this work can be extended to several other types of samples where both the average contents and the location of the elements are relevant. [ABSTRACT FROM AUTHOR]

The acid decomposition method was applied for the sample preparation of processed fruit juice. The decomposition of 15 mL of juice sample using HNO 3 and H 2 O 2 was performed in a digester block with reflux system and heated at 200 °C for 150 min. The limits of detection were 0.03; 0.24; 0.8; 0.008; 0.026 and 0.056 mg L −1 for Cr, Cu, K, Mg, Na and Zn, respectively and for Pb was 0.99 μg L −1 . The accuracy was evaluated by spiked experiments (80 to 119%). Four processed fruit juice samples commercialized in Brazil (strawberry, mango, peach, and orange) were analyzed and indicated the absence of Cr, Zn and Cu in the samples, except for Cu in strawberry juice. Pb was found in the mango juice sample (17.8 ± 0.9 μg L −1 ) and the concentration is below the maximum values recommended by Brazilian legislation for juices of citric fruits (0.3 mg kg −1 ). [ABSTRACT FROM AUTHOR]

The present work describes a sample preparation method using acid decomposition in reflux system for the determination of Hg on xanthan gum samples by cold vapor atomic absorption spectrometry (CV AAS). The best conditions of sample preparation method were optimized. This procedure proved to be safe for the quantification of this analyte, because no significant losses of Hg by volatilization, which is due to the efficient reflux system. The limits of detection and quantification were 0.0049 and 0.0163 μg g−1, respectively. The accuracy was evaluated through recovery tests performed with different species of Hg and CRM analysis, obtaining excellent recoveries. The values of Hg were below the LOD (m) for xanthan gum samples A and B. However, the other samples showed concentrations in the range of 0.027–0.325 μg g−1. The method proves suitable for the quantification of Hg, which is important due to the wide applicability of xanthan gum. [Display omitted] • Hg was determined in xanthan gum samples by CV AAS. • The samples were efficiently prepared using acid decomposition in reflux system. • Hg values found are below the established for tolerable daily intake in relation to body weight. [ABSTRACT FROM AUTHOR]