微波消解-石墨炉原子吸收光谱法测定食糖中的铅

Determination of lead in sugar by microwave digestion and graphite furnace-atomic absorption spectrometry(GF-AAS)

建立微波消解-石墨炉原子吸收光谱法测定食糖中铅的方法。样品经硝酸和过氧化氢消解,所得溶液蒸发浓缩后定容至25mL,分取适量用石墨炉原子吸收光谱法测定,得到铅的质量浓度在0.0～40.0μg/L范围内呈线性,相关系数为0.9992,检出限(S/N=3)为1.50μg/kg,回收率为98.0%～103.0%;用标准物质进行对照,其测定值均在给定的标准值范围之内。表明该方法具有简便、快速、安全、准确的特点,适合测定食糖中的铅含量。

The present study has been undertaken to develop a method for determination of lead in sugar by microwave digestion and graphite furnace-atomic absorption spectrometry（GF-AAS）. The sugar samples were digested with HNO3 and H202 solutions, the digested solution was heated to eliminate HNO3 and the final volume was made to 25 mL. The data obtained by GF-AAS analysis showed that the linear range of lead content in samples was ranging from 0-40.0ug/L. The relative coefficient was 0.9992 and the detection limit （S/N=3） was 1.50 ug/kg, and the recovery rate was found to be 0.9992, 1.50 ug/kg and 98.0%-103.0%. As used as the control, the lead content detected in standard sample was in range of standard value. The present method was found highly sensitive with aecurate precision and was rapid, safe and eonvenient, therefore, it could be used for the determination of lead content in sugar.