摘要
铝的化学形态分析是食品无机检测领域的重点内容之一。在含硅基质样品(如红薯粉)中,由于硅酸盐结构的化学惰性,结合态铝在传统硝酸体系中的溶出情况难以得到准确评估。现行标准主要针对添加剂铝进行监测,忽视了硅包裹态铝可能对实验结果产生的影响。本研究旨在建立一种适用于复杂硅基质样品的铝形态定量分析方法,实现外源添加剂铝与本底硅包裹铝的有效区分。为此,提出硝酸(HNO_(3))与硝酸-氢氟酸(HNO_(3)-HF)双体系联用策略,结合梯度控温微波消解技术,建立铝元素的微波消解-电感耦合等离子体发射光谱(ICP-OES)检测方法。通过对比两种酸体系的消解效率,优化微波消解温度梯度(120~200℃),实现添加剂铝(Al^(3+))与硅包裹铝(Al_(2)SiO_(5))的形态区分。实验表明,硝酸体系在190℃条件下可提取可溶性铝,硝酸-氢氟酸体系则通过破坏硅酸盐晶格释放总铝(含硅包裹铝)。优化后的微波消解温度梯度(120→150→190℃)保证了不同铝形态的分离效率。两种消解方式方法检出限分别为0.12 mg/kg(Al^(3+))和0.25 mg/kg(Al_(2)SiO_(5)),加标回收率95.2%~104%。在对20份市售红薯粉样品的检测中,硝酸-氢氟酸体系测得的铝含量显著高于硝酸体系,且高铝样品中差异尤为显著。本研究揭示了添加剂铝与结合态铝在不同酸体系下微波消解过程中的溶出规律,实现了复杂基质中铝化学形态的准确解析,可为食品中铝限量标准的完善提供技术参考。
The chemical speciation analysis of aluminum is one of the key aspects for the inorganic testing of food.In silicon-containing matrix samples,such as sweet potato flour,the chemical inertness of silicate structures makes it difficult to accurately evaluate the leaching of bound aluminum in conventional nitric acid systems.Current standards mainly monitor exogenous aluminum additives while neglecting the potential impact of silicon-encapsulated aluminum on analytical results.This study aims to establish a quantitative method for aluminum speciation in complex silicon-containing matrices,enabling the effective differentiation of exogenous additive aluminum and intrinsic silicon-encapsulated aluminum.To this end,a dual-acid system combining nitric acid(HNO_(3))and nitric acid-hydrofluoric acid(HNO_(3)-HF)was used,coupled with gradient-controlled microwave digestion,to develop a microwave digestion-inductively coupled plasma optical emission spectrometry(ICP-OES)method for aluminum detection.By comparing the digestion efficiencies of the two acid systems,the microwave digestion temperature gradient(120-200℃)was optimized to differentiate additive aluminum(Al^(3+))from silicon-encapsulated aluminum(Al_(2)SiO_(5)).Experimental results showed that the nitric acid system at 190℃could extract soluble aluminum,while the nitric acid-hydrofluoric acid system released total aluminum(including silicon-encapsulated aluminum)by breaking the silicate lattice.The optimized microwave digestion temperature gradient(120→150→190℃)ensured efficient separation of different aluminum species.The detection limits of the two digestion methods were 0.12 mg/kg(Al^(3+))and 0.25 mg/kg(Al_(2)SiO_(5)),with spiked recoveries ranging from 95.2%to 104%.In the analysis of 20 commercial sweet potato flour samples,aluminum content measured by the nitric acid-hydrofluoric acid system was significantly higher than that by the nitric acid system,particularly in high-aluminum samples.This study revealed the dissolution patterns of additive aluminum and bound aluminum during microwave digestion under different acid systems,enabling accurate speciation analysis of aluminum in complex matrices and providing a technical reference for the refinement of alumi num limits in foods.
作者
陆剑华
钟宏星
余健斌
钟艺维
陈小佩
余希文
李硕聪
LU Jianhua;ZHONG Hongxing;YU Jianbin;ZHONG Yiwei;CHEN Xiaopei;YU Xiwen;LI Shuocong(Institute of Biological and Medical Engineering,Guangdong Academy of Sciences,Guangdong,Guangzhou 510316,China;Engineering Technology Research Center of Sugarcane Industry,China National Light Industry Council,Guangdong,Guangzhou 510316,China)
出处
《中国无机分析化学》
北大核心
2026年第1期155-162,共8页
Chinese Journal of Inorganic Analytical Chemistry
基金
国家自然科学基金青年项目(32402224)
广东省基础与应用基础研究基金资助项目(2023A1515010998)。
关键词
铝形态
微波消解
硝酸-氢氟酸体系
电感耦合等离子体发射光谱
硅包裹铝
aluminum morphology
microwave digestion
nitric acid-hydrofluoric acid system
inductively coupled plasma spectroscopy
silicon-coated aluminum
