Determination of lead contents in tea and vegetable samples by isotope dilution coupled with inductively coupled plasma mass spectrometry
- 化学化工－已发表论文 
采用同位素稀释电感耦合等离子体质谱(ID-ICP-MS)法测定了铅的含量,通过对茶叶标准物质(GBW-07605)中铅的测定,考察了方法的准确度和精密度,比较了同位素稀释法与普通外标定量法的测定结果。在5mLHNO3～0.5mLHF～1mLH2O2的消解体系中,ID-ICP-MS法测量茶叶中铅的回收率可达97.7%,相对标准偏差(RSD)小于1.2%。实验对市售的12种茶叶和10种蔬菜中Pb进行测定,铅含量符合相应国家标准的样品分别占总样品数的83%和90%。该法适合于植物样品中微量铅的测定。A method of isotope dilution coupled with inductively coupled plasma mass spectrometry (ID-ICP-MS) was applied to determine lead contents in tea and vegetable samples. The accuracy and precision of the method were validated by the measurement of tea standard reference samples, and its results were compared with those of the quantitative mode of external calibration of ICP-MS. The recovery of the ID-ICP-MS mode was 93.9% with RSDs of than 1.2% in the digesting system of 5 mL HNO3～0.5 mL HF～1 mL H_2O_2, which was superior to the external calibration mode. Lead contents in 12 kinds of commercial tea and 10 kinds of vegetable samples were determined by ID-ICP-MS. The results showed that 83% and 90% of the tea and vegetable samples accorded with the limitations for the lead contents in the National Standards of China, respectively. The method of ID-ICP-MS, with the merits of high sensitivity and precision, is suitable for the measurement of lead contents in plants.