This work demonstrates the feasibility of halogen and sulfur determination in pitch produced from crude oil residues by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometry (ICP-OES), respectively, after digestion by microwave-induced combustion (MIC). Using the proposed system, it was possible to achieve a very effective digestion of pitch (up to 400 mg) using 20 bar of oxygen and 50 mL of 6 mol L À1 of ammonium nitrate as an ignition aid. Water and NH 4 OH solutions (10 to 100 mmol L À1 ) were evaluated for analyte absorption and a reflux step was applied after combustion in order to ensure quantitative analyte absorption. The volume of absorbing solution (6, 8, 10 and 12 mL) was also evaluated and best results were obtained using 6 mL confirming the results of previous studies. Accuracy was evaluated by comparison of results with those obtained using a total Cl and S analyzer, X-ray fluorescence (XRF, for Cl and S determination) and pyrohydrolysis followed by ICP-MS determination (Br and I). By using 50 mmol L À1 NH 4 OH as the absorbing solution the agreement with reference values ranged from 95 to 103% for all analytes. The results obtained using MIC presented an agreement of 101 and 100% with those obtained using a total Cl and S analyzer, respectively. The results were also compared with XRF analysis (for Cl and S) and agreement was 102 and 92%, respectively. In the same way, the results obtained by MIC were in agreement with those obtained by the pyrohydrolysis method (agreement of 97 and 105% for Br and I, respectively). The residual carbon content of MIC digests was always below 1% showing the high efficiency of pitch digestion. Using 400 mg of sample mass and 6 mL of 50 mmol L -1 NH 4 OH as the absorbing solution, limits of detection were 3.1 mg g À1 for S by ICP-OES and 3.2, 0.02 and 0.002 mg g À1 for Cl, Br and I by ICP-MS, respectively.

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Microwave-assisted solid sampling analysis coupled to flame furnace atomic absorption spectrometry (MW-SS-FF-AAS) was used for Cd and Pb determination in food-contact polymer samples, with the aim of minimizing reagents and laboratory waste. Operational parameters, such as the FF tube design, the oxygen flow rate, the flame stoichiometry, the sample mass, among others, were evaluated and optimized. Calibration was performed using only reference solutions, and the limits of quantification were 1.7 and 4.6 μg g−1 for Cd and Pb, respectively. Accuracy was assessed by the analysis of certified reference materials (CRMs), and by comparison with the results obtained by inductively coupled plasma mass spectrometry after microwave-assisted wet digestion. The MW-SS-FF-AAS results for the CRMs showed no statistical difference with the certified values, and good agreement was observed with the results of the digestion method. The MW-SS-FF-AAS method was considered suitable for Cd and Pb determination in food-contact polymers. The concentrations of Cd and Pb in the analyzed samples varied from <1.7 to 628 μg g−1, and from <4.6 to 614 μg g−1, respectively. As sample digestion is not necessary, the use of concentrated acids can be avoided by using the proposed MW-SS-FF-AAS method, greatly reducing waste generation.