范琼 赵敏 酒元达 吴小芳 王晓刚 韩丙军

摘要：【目的】研究双位加热消解—电感耦合等离子体质谱（双位加热消解—ICP-MS）的前处理和检测方法，并测定树仔菜中7种元素含量，建立一种测定树仔菜元素的简便、高效、准确方法，为科学开发树仔菜提供参考依据。【方法】比较分析双位加热消解—ICP-MS和微波消解—ICP-MS的空白背景值、检出限、准确度和精密度，考察消解条件（消解温度、赶酸温度和消解时间）对测定树仔菜中铜含量的影响，并通过正交试验确定最佳消解条件，建立双位加热消解—ICP-MS测定树仔菜中铅、镉、铬、砷、镍、铜和锌7种微量元素含量的方法。【结果】双位加热消解—ICP-MS和微波消解—ICP-MS的空白值與检出限均较低，但双位加热消解—ICP-MS测定的元素铬、镍、铜和锌检出限均低于微波消解—ICP-MS，差异达极显著水平（P<0.01，下同）。微波消解—ICP-MS测定标准物质GSB-26芹菜、GSB-12豆角和GSB-13蒜粉的准确度及精密度的相对标准偏差（RSD）≤5.0%;双位加热消解—ICP-MS准确度和精密度的RSD≤2.6%，低于微波消解—ICP-MS，差异达极显著水平，且测定结果更接近标准值。消解温度130 ℃下消解2.0 h后赶酸温度200 ℃为双位加热消解树仔菜的最佳消解条件，在此消解条件下ICP-MS测得树仔菜中铅、镉、铬、砷、镍、铜和锌7种元素含量分别为0.0790、0.0404、0.0350、0.00560、1.16、1.18和7.88 mg/kg。【结论】双位加热消解—ICP-MS具有操作简便、快速、检出限低、准确度和精密度高等优点，适用于树仔菜中铅、镉、铬、砷、镍、铜和锌含量的同时测定。

关键词： 双位加热消解法;电感耦合等离子体质谱（ICP-MS）;树仔菜;微量金属元素

中图分类号： S649;O657.3                          文献标志码： A 文章编号：2095-1191（2020）10-2515-08

Simultaneous determination of the contents of seven elements in Sauropus androgynus by double control heating and digestion - inductively coupled plasma mass spectrometry

FAN Qiong， ZHAO Min， JIU Yuan-da， WU Xiao-fang， WANG Xiao-gang，

HAN Bing-jun

（Testing and Analysis Center， Chinese Academy Tropical Agricultural Sciences/Hainan Provincial Key Laboratory of Quality and Safety for Tropical Fruits and Vegetables， Haikou  571101， China）

Abstract：【Objective】To build a quick，effective，accurate detection method to detect seven heavy metal elements contents of Sauropus androgynus（SA） by researching preparation methods and detection methods of double control hea-ting and digestion-inductively coupled plasma mass spectrometry method（DCD-ICP-MS）， which could provide reference for development of S. androgynus. 【Method】Blank value，detection limit，accuracy and precision of DCD-ICP-MS and microwave digestion ICP-MS method（MD-ICP-MS） were analyzed，effects of copper（Cu） content in S. androgynus at diffe-rent digestion conditions such as digestion temperature，remove acid temperature and digestion time were investigated， and through orthogonal experiment the digestion conditions were optimized. A method of the determination of lead（Pb），cadmium（Cd），chromium（Cr），arsenic（As）， nickel（Ni），Cu，zinc（Zn） contents in S. androgynus by DCD-ICP-MS was established. 【Result】The results showed that the blank value and detection limit（DL） of DCD-ICP-MS and MD-ICP-MS were low，but the DL of Cr，Ni，Cu and Zn detected by DCD-ICP-MS were lower than by MD-ICP-MS，and the difference was extremely significant（P<0.01，the same below）. The relative standard deviation（RSD） of accuracy and precision of standard substance GSB-26 celery，GSB-12 bean，GSB-13 garlic powder by MD-ICP-MS were ≤5.0%，RSD of accuracy and precision by DCD-ICP-MS was ≤2.6%，which was less than MD-ICP-MS， and results were closer to the standard va-lue，the difference was extremely significant. The optimum digestion conditions of S. androgynus by DCD-ICP-MS were digestion temperature of 130 ℃for 2.0 h and remove acid temperature of 200 ℃. At these optimum conditions，the contents of Pb，Cd，Cr，As，Ni，Cu，Zn in S. androgynus were 0.0790，0.0404，0.0350，0.00560，1.16，1.18，7.88 mg/kg，respectively. 【Conclusion】The DCD-ICP-MS method is simple，rapid，accurate and sensitive with low DL. It is suitable for the simultaneous determination and analysis of Pb，Cd，Cr，As，Ni，Cu，Zn of S. androgynus.

Key words： double control heating and digestion; inductively coupled plasma mass spectrometry（ICP-MS）; Sauropus androgynus; trace metal elements

Foundation item： Agricultural International Exchange and Cooperation Program of the Ministry of Agriculture and Rural Affairs（BARTP-12-HBJ）;Special Fund for Basic Scientific Research of Chinese Academy of Tropical Agricultural Sciences（1630082020003，1630082020004）

0 引言

【研究意義】海南树仔菜（Sauropus androgynus） 又名五指山野菜、泰国枸杞和越南菜等，为大戟科（Euphorbiaceae）守宫木属多年生灌木。树仔菜嫩梢可常年采收食用，口感清香脆嫩，食用无渣滓，风味独特，富含蛋白质、维生素和微量元素等营养成分（杨劲松等，2010;范琼等，2014;邓爱妮等，2017），具有清热解毒、养颜保健、降血压等功效。测定分析树仔菜的矿物质元素和重金属含量，对树仔菜的质量控制和安全评价有重要意义。【前人研究进展】电感耦合等离子体质谱（ICP-MS）具有多元素同时分析、灵敏度高、检出限低等特点，是目前痕量金属分析中的一种主要仪器。……