A simple, efficient, and reliable ultrasound-assisted digestion (UAD) procedure was used for sample preparation prior to quantitative determination of trace Cd and Pb contaminants in herbal medicines using flame atomic absorption spectrometry. The parameters influencing UAD such as the solvent system, sample mass, presonication time, sonication time, and digestion temperature were evaluated. The efficiency of the proposed UAD procedure was evaluated by comparing with conventional acid digestion (CAD) procedure. Under the optimum conditions, linear calibration graphs in a range of 2-250 μg/L for Cd, and 50-1000 μg/L for Pb were obtained with detection limits of 0.56 μg/L and 10.7 μg/L for Cd and Pb, respectively. The limit of quantification for Cd and Pb were 1.87 μg/L and 40.3 μg/L, respectively. The repeatability for analysis of 10 μg/L for Cd and 100 μg/L for Pb was 2.3% and 2.6%, respectively. The accuracy of the proposed method was evaluated by rice flour certified reference materials. The proposed method was successfully applied for analysis of trace Cd and Pb in samples of various types of medicinal plant and traditional medicine consumed in Thailand. Most herbal medicine samples were not contaminated with Cd or Pb. The contaminant levels for both metals were still lower than the maximum permissible levels of elements in medicinal plant materials and finished herbal products sets by the Ministry of Public Health of Thailand. The exception was the high level of Cd contamination found in two samples of processed medicinal plants.

中文翻译：

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在火焰原子吸收光谱法之前使用超声辅助消化对泰国草药中的痕量 Cd 和 Pb 污染物进行质量评估

在使用火焰原子吸收光谱法定量测定草药中痕量 Cd 和 Pb 污染物之前，使用简单、高效和可靠的超声辅助消解 (UAD) 程序进行样品制备。评估了影响 UAD 的参数，例如溶剂系统、样品质量、预超声时间、超声时间和消解温度。通过与传统的酸消解 (CAD) 程序进行比较，评估了所提出的 UAD 程序的效率。在最佳条件下，Cd 和 Pb 的检出限分别为 0.56 μg/L 和 10.7 μg/L，获得了 Cd 2-250 μg/L 和 Pb 50-1000 μg/L 范围内的线性校准图，分别。Cd 和 Pb 的定量限分别为 1.87 μg/L 和 40.3 μg/L。10 μg/L 的 Cd 和 100 μg/L 的 Pb 分析的重复性分别为 2.3% 和 2.6%。所提出方法的准确性通过米粉认证的参考物质进行了评估。该方法成功应用于泰国消费的各类药用植物和传统药物样品中痕量 Cd 和 Pb 的分析。大多数草药样品没有被 Cd 或 Pb 污染。这两种金属的污染水平仍低于泰国公共卫生部规定的药用植物材料和草药成品中元素的最高允许水平。一个例外是在两个加工药用植物样品中发现的高水平镉污染。所提出方法的准确性通过米粉认证的参考物质进行了评估。该方法成功应用于泰国消费的各类药用植物和传统药物样品中痕量 Cd 和 Pb 的分析。大多数草药样品没有被 Cd 或 Pb 污染。这两种金属的污染水平仍低于泰国公共卫生部规定的药用植物材料和草药成品中元素的最高允许水平。一个例外是在两个加工药用植物样品中发现的高水平镉污染。所提出方法的准确性通过米粉认证的参考物质进行了评估。该方法成功应用于泰国消费的各类药用植物和传统药物样品中痕量 Cd 和 Pb 的分析。大多数草药样品没有被 Cd 或 Pb 污染。这两种金属的污染水平仍低于泰国公共卫生部规定的药用植物材料和草药成品中元素的最高允许水平。一个例外是在两个加工药用植物样品中发现的高水平镉污染。大多数草药样品没有被 Cd 或 Pb 污染。这两种金属的污染水平仍低于泰国公共卫生部规定的药用植物材料和草药成品中元素的最高允许水平。一个例外是在两个加工药用植物样品中发现的高水平镉污染。大多数草药样品没有被 Cd 或 Pb 污染。这两种金属的污染水平仍低于泰国公共卫生部规定的药用植物材料和草药成品中元素的最高允许水平。一个例外是在两个加工药用植物样品中发现的高水平镉污染。