【摘要】 为提高石墨炉原子吸收光谱法测定山羊奶粉中铅含量的效率和准确性,对基体改进剂、石墨炉升温程序等试验条件进行了研究。在相同的石墨炉升温条件下,比较了不同浓度的磷酸二氢铵、硝酸钯和硝酸镁作为基体改进剂的效果。同时,在加入不同基体改进剂的条件下,分别对灰化温度和原子化温度进行了优化。结果表明,以0.02%硝酸钯为基体改进剂,灰化温度和原子化温度分别为950℃和1 600℃时,测定效果最佳。在0.0～25.0μg/L范围内,铅的吸光度与浓度之间的线性关系良好,检出限为0.009 mg/kg,定量限为0.03 mg/kg;加标回收率为95.7%～98.0%;重复测定试验结果的变异系数为2.7%。总之,该方法具有灵敏、准确、可重复的优势,适用于高效测定羊奶粉中的铅含量。更多还原

【Abstract】 In order to improve the efficiency and accuracy of graphite furnace atomic absorption spectrometry for the determination of lead in goat milk powder, the experimental conditions, such as matrix modifier and graphite furnace warming procedure, were investigated. The effects of different concentrations of NH₄ H₂ PO₄, Pd（NO₃）₂·2H₂O and Mg（NO₃）₂ as matrix modifiers were compared under the same graphite furnace heating conditions. Meanwhile, the ashing temperature and atomization temperature were optimized under the conditions of adding different matrix modifiers, respectively. The results showed that the best determination was achieved when 0.02% Pd（NO₃）₂·2H₂O was used as the matrix modifier and the ashing and atomization temperatures were 950 ℃ and 1 600 ℃, respectively. The linear relationship between the absorbance value and the concentration of lead was good in the range of 0.0-25.0 μg/L. The limit of detection was 0.009 mg/kg, and the limit of quantification was 0.03 mg/kg. The recoveries of the method were in the range of 95.7%-98.0%, and the coefficient of variation of the results of the repeated determination experiments was 2.7%. In conclusion, the method was sensitive, accurate, reproducible and suitable for the efficient determination of lead in goat milk powder.更多还原