【摘要】：如今隨著科技的迅猛發(fā)展,與人類息息相關(guān)的衣、食、住、行也都較之前發(fā)生了質(zhì)的飛躍,但是在這些物質(zhì)變化的同時,也催生出了威脅人類生命安全的添加劑、色素、殺蟲劑等有毒害的化學(xué)制劑,這就使人們對于自我保護的意識增強,越來越關(guān)心生存環(huán)境及食品安全的問題,因此各種檢測設(shè)備及測試方法、手段應(yīng)運而生。對于樣品中痕量重金屬元素的測定,有時需達(dá)到如ppb這樣高靈敏度級別的要求,單就目前應(yīng)用于實際生產(chǎn)工作中的較高靈敏度級別的儀器真正應(yīng)用到實際中常常達(dá)不到檢測要求,而且高靈敏度儀器的昂貴價格又使許多檢測實驗室或檢測機構(gòu)承受不起。所以從各方面考慮,應(yīng)該從普通儀器層面出發(fā),來提升檢測方法涉及的選擇性和靈敏度,因而就采用了分離富集共沉淀這一方法。共沉淀方法具有操作簡便、快捷、富集倍數(shù)高等優(yōu)點,且是一種應(yīng)用廣泛的分離富集預(yù)處理方法,與火焰原子吸收技術(shù)聯(lián)用可以降低成本、降低檢出限,提高靈敏度。本論文在研究痕量金屬含量測定的分析過程中,首次采用水楊基熒光酮(SAF)作為共沉淀劑,以Fe(Ⅲ)、Al(Ⅲ)、Ba(Ⅱ)作為載體離子。共沉淀分離富集食品及乳制品中的銅、錳、鉻、鉛,通過采用火焰原子吸收光譜法對上述四種痕量重金屬的含量進行分析測定。本實驗從載體離子的選取、載體離子的加入量、共沉淀劑的加入量、共沉淀的時間,樣品體積,溶液pH值、干擾性共存離子的含量限制等方面進行研究并優(yōu)化,最終得出了最優(yōu)共沉淀體系,并通過分析方法的靈敏度、檢出限、精密度等討論了該方法的優(yōu)越性。本文從以下四個體系研究了測定痕量重金屬:一、Fe(Ⅲ)-SAF共沉淀體系檢測Cu。該方法的靈敏度為0.4370(mg/L)~(-1),精密度是1.03%,其檢出限為1.26μg/L。二、Al(Ⅲ)-SAF共沉淀體系檢測Mn。該方法的靈敏度為1.1628(mg/L)~(-1),精密度是0.52%,其檢出限為0.38μg/L。三、Al(Ⅲ)-SAF共沉淀體系檢測Cr。該方法的靈敏度為0.2637(mg/L)~(-1),精密度是2.47%,其檢出限為2.09μg/L。四、Ba(Ⅱ)-SAF共沉淀體系檢測Pb。該方法的靈敏度為1.4265(mg/L)~(-1),精密度是1.73%,其檢出限為0.46 μg/L。上述四個體系對于重金屬離子Cu~(2+)、Mn~(2+)、Cr3+、Pb~(2+)有著很好的分離富集效果,能夠基本上消除基體的干擾。該預(yù)處理方法擁有操作簡便、檢出限較低、靈敏度較高、價格低廉等優(yōu)點,為火焰原子吸收光譜法測定食品和乳制品中重金屬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，

本文編號：2326913