石墨炉原子吸收法测定绞股蓝茶中铅含量  

Determination of Lead in Gynostemma pentaphyllum Tea by Graphite Furnace Atomic Absorption Spectrometry

作　　者：景文祥 练东明 姜勇 高会彬 周成强 

机构地区：[1]宜宾市林业科学研究院,宜宾644000

出　　处：《食品工业》2018年第3期306-308,共3页The Food Industry

基　　金：宜宾市科技计划(重点)项目为绞股蓝引种对比试验项目(2016ZNY005);2017年四川省林产品质量安全监测项目(2017-JC-03)等项目联合资助

摘　　要：绞股蓝茶因其含有丰富的皂苷及多种微量元素,味道纯正,长期饮用具有调节血压、增强免疫系统的功能而被人们所喜爱,但因产地环境、制备工艺的缺陷导致铅元素在绞股蓝茶中富集。试验以绞股蓝茶为研究对象,采用石墨炉原子吸收法测定其中铅元素的含量,通过优化基体改进剂、灰化温度和原子化温度等分析条件,对铅元素的线性范围、灵敏度、精密度及准确度进行评价,建立绞股蓝茶中铅元素的分析方法。优化结果:采用磷酸铵为基体改进剂,灰化温度900℃,原子化温度1 800℃,在该条件下,铅元素浓度在0~80 ng/m L的范围内与吸光度呈良好的线性关系(R^2=0.999 3),检出限为2.86μg/L,精密度良好(RSD=2.29%~3.25%),加标回收率为94.33%~102.32%。结果表明该方法准确、可靠,适合绞股蓝茶中铅元素含量的测定,对生产过程控制具有一定指导意义。Gynostemma pentaphyllum tea, containing saponins and multiple trace elements, senting forth its fragrances, becomes more and more popular. Drinking the product persistently can help to effectively regulate blood pressure and strengthen the immune system, etc. However, lead elements are enriched in Gynostemma pentaphyllum tea, owing to production environment and preparation technology. In this study, Gynostemma pentaphyllum tea as the object of analysis research, the technology of graphite furnace atomic absorption spectrometry is adopted to determine lead in Gynostemma pentaphyllum tea. In order to establish the analysis method of Pb in Gynostemma tea, optimize the matrix modifier, ashing temperature, atomization temperature, etc. The optimized analysis conditions are as follows： the matrix modifier of ammonium phosphate, ashing temperature 900 ℃, atomization temperature 1 800 ℃, the concentration of lead（0-80 ng/m L） has a linear relationship with absorbance（R^2=0.999 3）, detection limit is 2.86 μg/L, RSD is 2.29%-3.25%, recovery rate is 94.33%-102.32%. The results show that the method is accurate, reliable and suitable for the determination of lead in Gynostemma pentaphyllum tea, meanwhile, providing a certain guiding significance to the production process control.

关 键 词：绞股蓝茶 铅元素 石墨炉原子吸收法 优化 

分 类 号：O657.31[理学—分析化学] TS272.7[理学—化学]