食品中铝含量检测优化技术体系研究

Optimization of technology system for determination of aluminum content in foods

目的建立高效的测定食品中总铝和可溶性铝的测定方法。方法采用微波消解法(HNO_3、HNO_3+H_2SO_4、HNO_3+HF)与湿法消解法(HNO_3、HNO_3+H_2SO_4)进行样品前处理,在铬天青S分光光度法和电感耦合等离子体发射光谱法(inductively coupled plasma optical emission spectrometry,ICP-OES)下测定标准参考物质与普通样品铝含量,同时用添加回收实验验证方法的可靠性与准确性。结果采用微波消解法(HNO_3+HF)-优化铬天青S分光光度法和微波消解法(HNO_3+HF)-ICP-OES时,标准参考物质的铝含量测定结果在标准参考值范围内,这2种方法的加标回收率为86.5%~101.1%;采用微波消解(HNO_3)-ICP-OES法、微波消解(HNO_3)-铬天青S分光光度法与湿法消解(HNO_3+H_2SO_4)-铬天青S分光光度法时,测得普通样品的标准偏差为0.50~4.22 mg/kg,加标回收率为74.3%~99.0%。结论微波消解法(HNO_3+HF)-优化铬天青S分光光度法和微波消解法(HNO_3+HF)-ICP-OES法,均可准确测得总铝含量;微波消解(HNO_3)-ICP-OES法、微波消解(HNO_3)-铬天青S分光光度法与湿法消解(HNO_3+H_2SO_4)-铬天青S分光光度法测得的结果是可溶性铝。

Objective To establish the efficient method for the determination of soluble aluminum and total aluminum in foods. Methods The samples were pretreated by microwave digestion （HNO3, HNO3＋H2SO4, HNO3＋HF） and wet digestion （HNO3, HNO3＋H2SO4）, respectively. The aluminum content of standard reference materials and common food samples were determined by chromium azure S spectrophotometry and inductively coupled plasma optical emission spectrometry （ICP-OES）. The reliability and accuracy of these methods were verified by recovery tests. Results The determination results of aluminum content in the standard reference material by the microwave digestion method （HNO3＋HF）-optimized chromium azure S spectrophotometry and microwave digestion （HNO3＋HF）-ICP-OES were within the standard reference range. The recovery rates of the 2 methods were 86.5%-101.1%. The relative standard deviations of common food samples were in range of 0.50-4.22 mg/kg, and the recovery rates were in the range of 74.3%-99.0% by microwave digestion （HNO3）-ICP-OES method, microwave digestion （HNO3）- chromium azure S spectrophotometry and wet digestion （HNO3＋H2SO4）- chromium azure S spectrophotometry. Conclusion The total aluminum content can be determined accurately by microwave digestion （HNO3＋HF）-optimized chromium azure S spectrophotometry and microwave digestion （HNO3＋HF）-ICP-OES. The soluble aluminum content can be determined by microwave digestion （HNO3）-ICP-OES, microwave digestion （HNO3）- chromium azure S spectrophotometry and wet digestion （HNO3＋H2SO4）- chromium azure S spectrophotometry.