微波消解-电感耦合等离子体发射光谱法测定面制食品中总铝含量

Determination of total aluminum content in flour products with microwave digestion-inductively coupled plasma atomic emission spectrometry

目的 建立面制食品中总铝的微波消解-电感耦合等离子体发射光谱(inductively coupled plasma atomic emission spectrometry, ICP-AES)的测定方法。方法 优化雾化气和等离子气流量、HNO3浓度等实验参数,HNO3-H2O2、HNO3-HF-H2O2、HNO3-HF-H2O2-HClO4等3个样品消解体系,选取最优的微波消解程序,来用ICP-AES方法测定总铝含量。采用铝标准溶液系列绘制标准曲线,确定方法的线性方程和检出限;对5份生物成分标准物质和5份市售面制食品样品进行6次平行检测和加标试验,评估方法的精密度和准确度。结果 优选雾化气和等离子气流量分别为0.60 L/min和13.0 L/min, HNO3浓度为2.0%,采用HNO3-HF-H2O2-HClO4消解体系进行样品消解处理后,进行ICP-AES检测。该方法在0~7.0 mg/L质量浓度范围内线性良好(r=0.999 9),检出限为0.6 mg/kg,相对标准偏差(RSD)0.76%~5.19%,加标回收率90.6%~108.0%。4份生物成分标准物质中铝测定值均在标准值允许范围内,5份市售面制食品样品平均测定值7.8~81.2 mg/kg。结论 建立的HNO3-HF-H2O2-HClO4微波消解-电感耦合等离子体发射光谱法测定面制食品中总铝含量灵敏度高、准确性好、分析速度快,可用于面制食品中总铝含量的测定。

Objective To establish a microwave digestion-inductively coupled plasma atomic emission spectrometry(ICP-AES)for determination of total aluminum in flour products.Methods The nebulizer gas and plasma gas flow volumes,HNO3concentrations and HNO3-H 2 O2,HNO 3-HF-H2O 2 and HNO3-HF-H 2 O2-HCl O 4 digestion systems were optimized,and the optimal microwave digestion procedures were selected.The total aluminum content was determined in flour products with ICP-AES.The standard curve was plotted with standard aluminum solutions,and the linear equation and detection limit were measured.Five standard biological component mate-rials and 5 market-available flour food products were subjected to six parallel and spiked tests to evaluate the precision and accuracy.Results The nebulizer gas and plasma gas flow volumes were selected at 0.60 L/min and 13.0 L/min,and the HNO3concentration was selected at 2.0%.Following digestion with the HNO3-HF-H 2 O2-HCl O 4 system,ICP-AES was performed,and the method showed a high linear relationship at mass concentrations of 0 to 7.0 mg/L(r=0.9999),with a detection limit of 0.6 mg/kg,relative standard deviation of 0.76%to 5.19%and spiked recovery rate of 90.6%to 108.0%.The aluminum contents determined in four biological component standard materials were all within the range of the standard value,and the mean aluminum content was 7.8 to 81.2 mg/kg in five market-available flour food products.Conclusion The HNO3-HF-H 2 O2-HCl O 4 microwave digestion-ICP-AES is highly sensi-tive,accurate and rapid for determination of total aluminum in flour products,which is feasible for determination of total aluminum con-tents in flour products.