SAF共沉淀体系—火焰原子吸收法测定食品和乳制品中的铜、锰、铬、铅
发布时间：2018-11-12 11:01
【摘要】：如今随着科技的迅猛发展,与人类息息相关的衣、食、住、行也都较之前发生了质的飞跃,但是在这些物质变化的同时,也催生出了威胁人类生命安全的添加剂、色素、杀虫剂等有毒害的化学制剂,这就使人们对于自我保护的意识增强,越来越关心生存环境及食品安全的问题,因此各种检测设备及测试方法、手段应运而生。对于样品中痕量重金属元素的测定,有时需达到如ppb这样高灵敏度级别的要求,单就目前应用于实际生产工作中的较高灵敏度级别的仪器真正应用到实际中常常达不到检测要求,而且高灵敏度仪器的昂贵价格又使许多检测实验室或检测机构承受不起。所以从各方面考虑,应该从普通仪器层面出发,来提升检测方法涉及的选择性和灵敏度,因而就采用了分离富集共沉淀这一方法。共沉淀方法具有操作简便、快捷、富集倍数高等优点,且是一种应用广泛的分离富集预处理方法,与火焰原子吸收技术联用可以降低成本、降低检出限,提高灵敏度。本论文在研究痕量金属含量测定的分析过程中,首次采用水杨基荧光酮(SAF)作为共沉淀剂,以Fe(Ⅲ)、Al(Ⅲ)、Ba(Ⅱ)作为载体离子。共沉淀分离富集食品及乳制品中的铜、锰、铬、铅,通过采用火焰原子吸收光谱法对上述四种痕量重金属的含量进行分析测定。本实验从载体离子的选取、载体离子的加入量、共沉淀剂的加入量、共沉淀的时间,样品体积,溶液pH值、干扰性共存离子的含量限制等方面进行研究并优化,最终得出了最优共沉淀体系,并通过分析方法的灵敏度、检出限、精密度等讨论了该方法的优越性。本文从以下四个体系研究了测定痕量重金属:一、Fe(Ⅲ)-SAF共沉淀体系检测Cu。该方法的灵敏度为0.4370(mg/L)~(-1),精密度是1.03%,其检出限为1.26μg/L。二、Al(Ⅲ)-SAF共沉淀体系检测Mn。该方法的灵敏度为1.1628(mg/L)~(-1),精密度是0.52%,其检出限为0.38μg/L。三、Al(Ⅲ)-SAF共沉淀体系检测Cr。该方法的灵敏度为0.2637(mg/L)~(-1),精密度是2.47%,其检出限为2.09μg/L。四、Ba(Ⅱ)-SAF共沉淀体系检测Pb。该方法的灵敏度为1.4265(mg/L)~(-1),精密度是1.73%,其检出限为0.46 μg/L。上述四个体系对于重金属离子Cu~(2+)、Mn~(2+)、Cr3+、Pb~(2+)有着很好的分离富集效果,能够基本上消除基体的干扰。该预处理方法拥有操作简便、检出限较低、灵敏度较高、价格低廉等优点,为火焰原子吸收光谱法测定食品和乳制品中重金属的含量提供了新的分析方法。
[Abstract]:Nowadays, with the rapid development of science and technology, clothing, food, housing and transportation, which are closely related to human beings, have all undergone a qualitative leap. But while these substances have changed, they have also given birth to additives, pigments, which threaten the safety of human life. Insecticides and other toxic chemical agents, which make people more and more aware of self-protection, more and more concerned about the living environment and food safety, so a variety of testing equipment and testing methods came into being. For the determination of trace heavy metals in samples, it is sometimes necessary to meet the requirements of high sensitivity levels such as ppb. At present, the instruments of high sensitivity level which are used in actual production work are often unable to meet the requirements of detection, and the high price of high sensitivity instruments makes many testing laboratories or testing institutions unable to afford them. Therefore, the selectivity and sensitivity of the detection method should be improved from the general instrument level, so the separation, enrichment and coprecipitation method is adopted. The coprecipitation method has the advantages of simple operation, fast operation, high enrichment ratio and so on. It is a widely used separation and preconcentration pretreatment method. Combined with flame atomic absorption technology, it can reduce the cost, reduce the detection limit and improve the sensitivity. In this paper, in the analysis of trace metal content, salicylfluorone (SAF) was used as coprecipitation agent and Fe (鈪，
本文编号：2326913
[Abstract]:Nowadays, with the rapid development of science and technology, clothing, food, housing and transportation, which are closely related to human beings, have all undergone a qualitative leap. But while these substances have changed, they have also given birth to additives, pigments, which threaten the safety of human life. Insecticides and other toxic chemical agents, which make people more and more aware of self-protection, more and more concerned about the living environment and food safety, so a variety of testing equipment and testing methods came into being. For the determination of trace heavy metals in samples, it is sometimes necessary to meet the requirements of high sensitivity levels such as ppb. At present, the instruments of high sensitivity level which are used in actual production work are often unable to meet the requirements of detection, and the high price of high sensitivity instruments makes many testing laboratories or testing institutions unable to afford them. Therefore, the selectivity and sensitivity of the detection method should be improved from the general instrument level, so the separation, enrichment and coprecipitation method is adopted. The coprecipitation method has the advantages of simple operation, fast operation, high enrichment ratio and so on. It is a widely used separation and preconcentration pretreatment method. Combined with flame atomic absorption technology, it can reduce the cost, reduce the detection limit and improve the sensitivity. In this paper, in the analysis of trace metal content, salicylfluorone (SAF) was used as coprecipitation agent and Fe (鈪，
本文编号：2326913
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