目的 建立使用微波消解样品,石墨炉原子吸收光谱法测定蔬菜和水果中铅、镉、镍、铬的方法。方法 样品加8 ml硝酸,预消化1 h左右,再经微波消解,并优化灰化原子化温度,以氯化钯-磷酸二氢铵混合溶液为基体改进剂测定铅、镉、镍含量,铬检测不加基改,用石墨炉原子吸收光谱法测定。结果 铅、镉、镍、铬的线性范围分别在0～50 μg/L、0～4 μg/L、0～40 μg/L、0～16 μg/L,方法检出限分别为0.413 μg/L、 0.043 μg/L、0.154 μg/L和0.130 μg/L。铅、镉、镍、铬标准曲线相关系数分别为0.9958、 0.9973、 0.9984和0.9992,相对标准偏差为0.85%～3.87%,样品加标回收率为91.5%-101.8%。结论 该方法精密度高,样品加标回收率好,可作为检测蔬菜水果中铅、镉、镍、铬含量快捷、可靠的方法。

Objective A microwave digestion method for the determination of lead,cadmium,nickel and chromium content in vegetables and fruits by graphite funnace atomic absorptionspectrometry. Methods The samples with 8 ml nitric acid predigested for 1 hours, followed by microwave digestion, and optimize the ashing atomic temperature and palladium chloride with hydrogen ammonium phosphate mixed solution as matriix modifier for detemination of lead ,cadmium, nickel chromium content detection,matrix modifier by graphite funnace atomic absorption spectrometry. Results The linear range of lead, cadmium, nickel and chromium in 0-50 μg/L,0-4 μg/L,0-40 μg/L, 0-16 μg/L, the detection limit of the method were 0.413 μg/L, 0.043 μg/L, 0.154 μg/L and 0.130 μg/L. The correlation coefficient of lead, cadmium, nickel, chromium standard curves were 0.99, 0.99, 0.99 and 0.99, the relative standard deviation is 0.85%-3.87%, the recoveries were 91.5% ~ 101.8%. Conclusion The method has high precision and good recoveries can be used as a fast and reliable method for detection of chromium, lead and cadmium in vegetables and fruits.