Abstract A highly sensitive, selective and rapid method for the determination of lead based on the reaction of lead(II) with 5-(4′-chlorophenylazo)-6-hydroxypyrimidine-2,4-dione (CPAHPD) and the solid phase extraction of the Pb(II)–CPAHPD complex with Amberlite XAD-2000 was developed, in the presence of pH 5.6 buffer solution and Triton X-114 medium. CPAHPD reacts with lead to form a violet complex with a molar ratio of 2:1 (CPAHPD to lead). This complex was enriched by the solid phase extraction with Amberlite XAD-2000. An enrichment factor of 500 was obtained by elution of the complex from the resin with a minimal amount of isopentyl alcohol (0.2 mL). In isopentyl alcohol medium, the molar absorptivity of the complex is 1.13 × 106 L mol−1 cm−1 at 647 nm. Beer’s law is obeyed in the range of 5.0–160 ng mL−1 in the measured solution. The relative standard deviation for 10 replicate samples of 50 ng mL−1 level is 1.26%. The detection and quantification limits reaches 1.5 and 4.7 ng mL−1 in the original samples. The presented procedure was successfully applied for determination of lead content in real samples such as vegetables, waters, biological and soil samples with satisfactory results.

中文翻译：

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固相萃取在水、蔬菜、生物和土壤样品中铅的比色测定中的应用

摘要 基于铅 (II) 与 5-(4'-氯苯基偶氮)-6-羟基嘧啶-2,4-二酮 (CPAHPD) 反应和固相萃取的高灵敏度、选择性和快速测定铅的方法在 pH 5.6 缓冲溶液和 Triton X-114 培养基存在的情况下，开发了 Pb(II)-CPAHPD 复合物与 Amberlite XAD-2000。CPAHPD 与铅反应形成摩尔比为 2:1（CPAHPD 与铅）的紫色络合物。该复合物通过用 Amberlite XAD-2000 进行固相萃取而富集。通过用最少量的异戊醇 (0.2 mL) 从树脂中洗脱复合物，获得了 500 的富集因子。在异戊醇介质中，配合物在 647 nm 处的摩尔吸收率为 1.13 × 106 L mol-1 cm-1。被测溶液在 5.0–160 ng mL-1 范围内遵守比尔定律。50 ng mL-1 水平的 10 个重复样品的相对标准偏差为 1.26%。原始样品的检测和定量限分别达到 1.5 和 4.7 ng mL-1。所提出的程序已成功应用于测定实际样品中的铅含量，例如蔬菜、水、生物和土壤样品，结果令人满意。