PDF《ICP-AES 测定茶包中总铝及水溶性铝的含量》

・869・ ICP-AES 测定茶包中总铝及水溶性铝的含量 吴莉, 王玉 (江苏省食品药品监督检验研究院, 南京 210008) 摘要 目的: 建立电感耦合等离子体原子发射光谱法 (ICP-AES 法)测定茶包中总铝及水溶性铝含量.

方法: 样品经微波消解消化处理, 采用 ICP-AES 法测定茶包中总铝及水溶性铝含量, 样品导入泵速

30 r・min-1 , 功率

1 100 W, 等离子气流量 15.0 L・min-1 , 辅助气流量 1.5 L・min-1 , 雾化器压力

200 kPa, 载气为 高纯氩气, 以内标法计算, 选择待测元素铝波长为 396.152 nm, 内标钪波长为 361.383 nm.结果: ICP-AES 法测定茶包中铝元素, 线性范围为 0~25 mg・L-1 (校准曲线相关系数 r=0.999 7) ;

加样回收率平均值 (n=9) 为95.6%, RSD 为1.3%;

检测限为 0.6 mg・kg-1 ;

重复性 RSD 为1.3% (n=6) ;

总铝含量范围为 117~1

046 mg・kg-1 , 水溶性铝含量范围为 36~367 mg・kg-1 .结论: 本法适用于茶包中总铝及水溶性铝的含量测定.第1次冲泡的茶水中铝含量较高. 关键词: 电感耦合等离子体原子发射光谱法 (ICP-AES) ;

茶包;

铝;

水溶性铝;

微波消解 中图分类号: R

917 文献标识码: A 文章编号: 0254-1793 (2017) 05-0869-06 doi: 10.16155/j.0254-1793.2017.05.18 Quantitative analysis of total aluminium and water soluble aluminium in tea bags by ICP-AES WU Li, WANG Yu (Jiangsu Institute for Food and Drug Control, Nanjing 210008, China) Abstract Objective: To establish an ICP-AES method for the quantitative analysis of total aluminium and water soluble aluminium in tea bags. Methods: Microwave digestion was used for sample pre-treatment. The content of total aluminium and water soluble aluminium were measured by internal standard method using ICP-AES, respectively. The pump speed was

30 r・min-1 . The power was

1 100 W. The flow rate of plasma gas was 15.0 L・min-1 . The flow rate of auxiliary gas was 1.5 L・min-1 . The nebulizer pressure was

200 kPa, and the carrier gas was high purity argon. The wavelength of Al was set at 396.152 nm and the wavelength of Sc as the internal standard element was 361.383 nm. Results: The calibration curve of total aluminium in tea bags has good linearity between

0 mg・L-1 and

25 mg ・L-1 (calibration curve correlation coefficient r =0.999 7) . The mean recovery rate(n=9) was 95.6% and the RSD was 1.3%. The detection limit of the method was 0.6 mg・kg-1 . The repeatability of RSD was 1.3%(n=6) . The amount of total aluminum ranged from

117 to

1046 mg・kg-1 . The amount of water soluble aluminium ranged from

36 to

367 mg・kg-1 . Conclusion: This method is suitable for the quantitative analysis of total aluminium and water 第一作者 Tel: (025) 86630712;

E-mail: wulienglish@sohu.com ・870・ soluble aluminium in tea bags. The amount of water soluble aluminium in tea bags for the first time was higher. Keywords: inductively coupled plasma atomic emission spectrometry (ICP-AES) ;

tea bags;

aluminium;

water soluble aluminium;

microwave digestion A 牌减肥茶包 (批号 20150805) 、 B 牌减肥茶包 (批号

150603、

150809、 151112) 、 B 牌常润茶包 (批号 150404) 、 C 牌减肥茶包 (批号

20150116、 20150819) 、 D 牌通秘茶包 (批号 AE

150912、 AE151019)和E牌减肥茶包 (批号 20150711) 规格均为每袋 2.5 g, 从市 场购买.

2 方法与结果 2.1 溶液的制备 2.1.1 内标溶液 精密量取

1 000 mg・L-1 钪单元素 标准溶液

5 mL, 置50 mL 量瓶中, 加1% 硝酸溶液稀 释定容至刻度, 摇匀, 制成