高盐食品基质中砷含量的测定

Determination of Arsenic Content in High-salt Food Matrices

摘要:

建立了一种基体匹配-动态反应池-电感耦合等离子体质谱法测定高盐食品基质中砷含量的方法，以解决高盐基体对砷测定的质谱干扰和基体干扰。研究电感耦合等离子体质谱法与氢化物发生原子荧光光谱法测定食品中总砷的技术要点，通过分析前处理消解方式、有机基质、氯含量和内标校正元素等对砷含量测定的影响，建立了高盐食品基质中砷含量的测定方法。实验结果表明，微波消解法并不太适用于氢化物发生原子荧光光谱法测定食品中总砷，有机基质和氯分别会对砷的质谱测定信号产生增敏效应和质谱干扰，74Ge比72Ge更适合作为电感耦合等离子体质谱法测定食品中总砷的内标元素。建立的检测方法定量限0.010 mg/kg，高盐基体中砷在0.010、0.025、0.20、0.50 mg/kg添加水平的回收率为91.50%~110.80%，相对标准偏差范围为0.76%~7.22%。本法和参照法对样品分析结果统计值均大于t0.90,10（1.81，双边），测定结果存在显著性差异，对实际样品测定结果表明动能歧视测定模式并不太适用于高盐食品基质样品中总砷的测定。该方法准确可靠，能用于高盐和高基体食品中砷含量的测定分析。

Abstract:

A matrix matching-dynamic reaction cell-inductively coupled plasma mass spectrometry method for determining the arsenic content in high-salt food matrices was established, to solve the mass spectrum interference and matrix interference of a high-salt matrix on arsenic determination. The key technical points for the determination of total arsenic in foods by inductively coupled plasma mass spectrometry and hydride generation atomic fluorescence spectrometry were investigated. A method for determining the arsenic in high-salt food matrices was established through analyzing the effects of pretreatment and digestion methods, organic matrix, chlorine content and internal standard correction elements on the determination of arsenic content. The experimental results show that the microwave digestion method is not quite suitable for the determination of total arsenic in food by hydride generation atomic fluorescence spectrometry. The organic matrix and chlorine will produce a sensitizing effect and mass spectral interference on the mass spectrometry signal of arsenic, respectively. 74Ge is more suitable than 72Ge as an internal standard element for the determination of total arsenic in food by inductively coupled plasma mass spectrometry. LOQ of the established method was 0.010 mg/kg, recovery rate of arsenic in high-salt matrices was 91.50%~110.80% when the addition level was 0.010, 0.025, 0.20 or 0.50 mg/kg, and the relative standard deviation range was 0.76%~7.22%. The statistical values of the sample analysis results obtained by this method and the reference method were both higher than t0.90,10 (1.81, bilateral), and there is a significant difference in the determination results. The measurement results of actual samples revealed that the kinetic energy discrimination measurement model is not suitable for the determination of total arsenic in high-salt food matrix samples. The method is accurate and reliable, and can be applied for the determination of arsenic content in high salt-and high-matrix foods.