微波消解-微波等离子体炬原子发射光谱测定啤酒中的铜、锌、铁、锰、硒、锶

建立了微波消解-微波等离子体炬原子发射光谱(MPT-AES)法测定啤酒中微量元素。考察了微波前向功率、工作气流量、载气流量等参数,确定了MPT-AES法测定各元素的最佳实验条件。在该条件下铜、锌、铁、锰、硒、锶的检出限分别为7ng.mL-1、46ng.mL-1、13ng.mL-1、8ng.mL-1、1.2ng.mL-1、5.6ng.mL-1。相对标准偏差(RSD)均在0.9%～4.8%之间,线性范围分别为0.1～100μg.mL-1、0.5～100μg.mL-1、0.5～100μg.mL-1、0.1～100μg.mL-1、0.01～10μg.mL-1、0.05～100μg.mL-1,加标回收率均在96%～110%之间。

Determination of Cu, Zn, Fe, Mn, Se and Sr in Beer by Microwave-Assisted Digestion-MPT-AES

Microwave plasma torch atomic emission spectrometry(MPT-AES) was used to determine metal elements in different beer samples after microwave digestion,and the optimum conditions for microwave digestion were also investigated.The samples were digested with the help of microwave in two steps.The eptimal operating parameters for the two-step digestion were as follows:digestion time,temperature and pressure were 4min and 5min,120 ℃ and 150 ℃,0.15 MPa and 0.25 MPa respectively.The optimal conditions for MPT-AES were studied,such as microwave power,flow rate of work gas,flow rate of carrier gas,and concentrations of acid such as HCl and HNO3.The detection limit for copper,zinc,iron,manganese,selenium,and strontium were 7,46,13,8,1.2,5.6 ng·mL-1,respectively.The RSDs were between 0.9%~4.8%.The linear range were 0.1~100,0.5~100,0.5~100,0.1~100,0.01~10 and 0.05~100 μg·mL-1 for the above six ions,respectively.Standard addition recoveries were between 96%~110%.