微波消解-ICP-MS法测定红薯中18种元素

Determination of 18 elements in sweet potato by microwave digestion-ICP-MS

建立电感耦合等离子体质谱法和在线内标法测定3个红薯品种(黄心红薯、白心红薯、紫红薯)生红薯、熟红薯、红薯皮及表面土壤中铅(Pb)、砷(As)、镉(Cd)、汞(Hg)、铬(Cr)、钴(Co)、铝(Al)7种重金属元素及钠(Na)、钾(K)、钙(Ca)、锌(Zn)、硒(Se)、镁(Mg)、铁(Fe)、锰(Mn)、镍(Ni)、铜(Cu)、锡(Sn)11种微量元素的方法。对红薯样品微波消解体系进行优化,红薯样品经微波消解后,进行ICP-MS测定,并对方法的线性关系、检出限、定量限、回收率、精密度进行考察。进行3种生红薯、熟红薯、红薯表皮、红薯表面附着土壤的研究,用加标回收对测定方法准确度进行验证。结果表明,选择硝酸-双氧水的消解体系,样品消解更完全;18种元素标准品的标准曲线的相关系数R≥0.994,回收率86.8%~98.3%,重金属元素的方法检出限均低于0.5μg/L,微量元素的方法检出限均低于50μg/L;相对标准偏差小于5%;不同品种生红薯、熟红薯、红薯皮及表面土壤中重金属元素及微量元素含量各有差异。方法快速、准确、灵敏度高、定量准确,可用于红薯中重金属及微量元素的测定。

Inductively coupled plasma mass spectrometry(ICP-MS)and on-line internal standard method were establishedfor the determination of seven heavy metal elements,includingplumbum(PB),arsenic(as),cadmium(CD),mercury(Hg),chromium(CR),cobalt(CO)and aluminum(AL),and 11 trace elements of sodium(Na),potassium(K),calcium(Ca),zinc(Zn),selenium(Se),magnesium(Mg),iron(Fe),manganese(Mn),nickel(Ni),copper(Cu),tin(Sn)in raw sweet potato,ripe sweet potato,sweet potato,potato skin and surface soil of three sweet potato varieties(Huangxin sweet potato,Baixin sweet potato and purple sweet potato).The microwave digestion system of sweet potato samples was optimized.After microwave digestion,thesamples were determined byICP-MS.The linear relationship,detection limit,quantitative limit,recovery rate and precision of the method were investigated.Three kinds of raw sweet potatoes,ripe sweet potatoes,sweet potato epidermis and sweet potato surface attached soil were studied.The accuracy of the determination method was verified by standard addition recovery.The nitric acid-hydrogen peroxide digestion system was selected,and the sample digestion was more complete.The correlation coefficients of standard curves for 18 kinds of elements are more than or equal to 0.994,and the recovery rates are between 86.8%and 98.3%.The detection limits for heavy metals are lower than 0.5μg/L and for trace elements are lower than 50μg/L.The relative standard deviation is less than 5%.The contents of heavy metals and trace elements in raw sweet potato,ripe sweet potato,sweet potato skin and surface soil of different varieties are different.The method is rapid,sensitive and accurate,and can be used for the determination of heavy metals and trace elements in sweet potatoes.