测定鲜蛋中痕量铅的石墨炉原子吸收光谱法

目的探索石墨炉原子吸收光谱法测定鲜蛋中痕量铅的检测条件。方法样品用硝酸一高氯酸消化后，添加基体改进剂磷酸二氢铵，用自动进样器进样测定铅。试验了基体改进剂用量、灰化温度和原子化温度对吸光度的影响。结果在该试验条件下，铅的检出限为0．38wg／L，精密度为2．6％，回收率为95％-101%，铅在0．0～20．0wg／L浓度范围内，与其吸光度呈良好的线性关系，线性方程Y=0．007 1x＋0．0052，相关系数R^2=0．9996。结论该方法灵敏度高，准确，适合鲜蛋中痕量铅的检测。

Determination of trace lead in fresh egg by graphite furnace atomic absorption spectrometry

Objective] To explore the detection conditions in the determination of trace lead in fresh egg by graphite furnace atomic absorption spectrometry （ GFAAS）. Methods] The samples were digested by nitric acid-perchloric acid, the ammonium dihydrogen phosphate was used as the matrix modifier, and the trace lead was detected by automatic sampling. The influences of matrix modifi- er dosage, ashing temperature and atomization temperature on absorbency were tested. Results] Under these conditions, the detec- tion limit of lead was 0.38 tLg/L, the precision was 2.6%, and the recovery rate was 95% -101%. Within the range of 0.0-20.0 Ixg/L, the lead concentration had good linear relationship with absorbency, the linear equation was described as follows： y = 0.007 lx ＋ 0. 005 2, and the correlation coefficient R2 was 0. 999 6. Conclusion] This method has high sensitivity and good accuracy, and it is suitable for determination of trace lead in fresh egg.