恒压消解-TXRF测定核桃中的16种矿物元素

Determination of 16 Mineral Elements in Walnut by Total Reflection X-ray Fluorescence with Constant Pressure Digestion

摘要:

建立了恒压湿法消解-全反射X射线荧光分析（TXRF）测定核桃中K、Ca、Ti、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Se、Rb、Sr和Pb等16种矿物元素的新方法。优化了恒压消解的最佳条件为：180 ℃消解4 h。以花粉标准物质为样品，在最佳条件下进行消解、测定，并计算得出K等16种矿物元素的仪器检出限（LLD）在0.001~0.045 mg/L范围，方法检出限（LDM）在0.003~0.144 mg/kg范围，这16种矿物元素的测定值均在花粉标准物质的认定值范围内。该方法前处理设备投资少、操作简单、样品用量少、检出限低，将该方用于核桃中的16种矿物元素分析，测定结果与ICP-MS法无显著性差异，且相对标准偏差（RSD）在0~3.9%范围内。

Abstract:

A method for the determination of 16 mineral elements, such as K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr and Pb in walnut was developed by total reflection X-ray fluorescence (TXRF) with constant pressure digestion. The optimized temperature and time of the constant pressure digestion were 180 ℃ and 4 h, respectively. The certified reference material (CRM, GBW10026) was digested and determined. And the lower limit of detection (LLD) and the limit of determination (LDM) of different element in walnut were calculated. calculated to be 0.001~0.045 mg/L and 0.003~0.144 mg/kg, respectively. TXRF analytical results showed that the 16 mineral elements in the CRM consistent were within the standard value ranges. This method showed advantages in lower cost of the pretreatment equipment, easy operation, less sample consumption and low detection limit. The contents of 16 mineral elements in walnut determined by this method showed little difference with the results by ICP-MS. The relative standard deviations (RSD) of TXRF were lower than 3.9%.