Sample preparation methodsforcereal digestion were evaluated for the first time for subsequent As, Cd, Hg, and Pb determination by atomic absorption spectroscopy techniques. Microwave-assisted digestion (MW-AD) under high and medium pressure and microwave-induced combustion (MIC) were evaluated. The use of MIC made it possible to digest 700 mg of samples, and agreements of 97, 96, 100 and 92% were obtained for As, Cd, Hg and Pb, respectively, when 7 mol L-1 HNO3 was used as the absorbing solution. It was not necessary to dilute the digests obtained to avoid interferences in the quantification of As, Cd, Hg, and Pb. Although high pressure MW-AD was efficient for cereal digestion, interferences were observed on analyte determination. Limits of quantification obtained by MIC were 0.034 (As), 0.015 (Cd), 0.021 (Hg) and 0.105 (Pb) μg g-1, which are suitable to attain the maximum levels recommended by international agencies in cereal samples.

中文翻译：

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通过基于AAS的技术评估谷物消化的样品制备方法，以便随后测定As，Cd，Hg和Pb。

通过原子吸收光谱技术，首次评估了样品制备方法的力消解，用于随后的As，Cd，Hg和Pb测定。评估了高压和中压下的微波辅助消解（MW-AD）和微波诱导燃烧（MIC）。使用MIC可以消化700 mg的样品，当使用7 mol L-1 HNO3作为吸收剂时，As，Cd，Hg和Pb的协议分别达到97％，96％，100％和92％解。无需稀释所获得的消化物，以避免干扰As，Cd，Hg和Pb的定量。尽管高压MW-AD对谷物的消化很有效，但在分析物测定中却观察到了干扰。通过MIC获得的定量限为0.034（As），0.015（Cd），0.021（Hg）和0.105（Pb）μgg-1，