郑州市枸杞中铅含量的直读法测定及其分布特性

为建立一种快速测定食品中微量铅的新方法，以郑州市区的枸杞为材料，用微波压力消解技术快速处理样品，用铅离子选择性电极测定枸杞果、叶、茎中的铅含量并对其分布规律进行研究。结果表明：枸杞铅含量为果中68.86μg/g、叶中38.59μg/g、茎中31.33μg/g，加标回收率为94.6%～103.2%，相对标准偏差为0.9%～1.7%(n=11)，铅的最低检出限为0.0103mg/L，测定的线性范围为0.105～204.7mg/L，相关系数为0.9990，电极斜率为27.367。该方法具有直观、简便、灵敏、准确、适于现场进行快速测定的显著优点。

Determination and Distribution Analysis of Lead Content in Different Organs of Wolfberry in Zhengzhou Suburb by Direction Reading Method

A novel quick method to determine lead content in foods was proposed by direct reading on an ionic analyzer equipped with a lead-selective electrode following pressurized microwave digestion of samples. The lead contents of wolfberry fruits, leaves and stems from the same cluster in Zhengzhou suburb as determined by the method were 68.86, 38.59 μg/g and 31.33 μg/g, respectively. The average recoveries for lead in spiked wolfberry fruits, leaves and stems were between 94.6% and 103.2%, with relative standard deviation (RSD) of 0.9% to 1.7% (n = 11). The limit of detection for lead was 0.0103 mg/L. The calibration curve of the method was linear over the range of 0.105 to 204.7 mg/L, with a correlation coefficient of 0.9990. The electrode slope obtained was 27.367. This method proved to have the advantages of directness, simplicity, high sensitivity and accuracy and suitability of rapid on-the-spot determination.