本文選題：多接收等離子體質(zhì)譜　切入點：鋅同位素　出處：《西北大學》2017年碩士論文　論文類型：學位論文

【摘要】：由于鋅在成礦作用,生命活動,現(xiàn)代工業(yè)等方面的多種應用,研究鋅同位素組成具有重要意義。而鋅同位素分析方法沒有確定公認的參考標準極大的影響了各實驗室數(shù)據(jù)的相互對比及其他實際樣品的分析測試。由于多接收等離子體質(zhì)譜分析速度快,靈敏度高,因而在同位素分析上得到了廣泛的應用,但該方法對樣品的前處理要求嚴格,而樣品分離純化的時間長,效率低,制約了分析方法的應用,因此提高樣品前處理效率已成為迫切需求。本文研究了多接收等離子體質(zhì)譜對鋅同位素的高精度分析測試方法,同時開發(fā)了同位素快速分離方法,并以銅、鍶、釹同位素分離方法為例驗證其可靠性。主要研究內(nèi)容包括以下幾點:1.確定鋅同位素樣品溶解、分離方法以及分析測試方法。采用AG1-X8強堿性陰離子交換樹脂進行分離,該分離流程相對較短,能夠減少本底的引入,回收率達到99.33%。利用MC-ICP-MS對鋅同位素進行分析測試,優(yōu)化儀器參數(shù),分析了不同進樣方式對分析結(jié)果的影響,實驗證實利用膜去溶裝置的干法進樣更具有優(yōu)勢,得到的分析結(jié)果精度更高,同時樣品用量更少,有利于較低含量的鋅同位素分析。對測試中可能產(chǎn)生的濃度效應與酸度效應進行了分析,發(fā)現(xiàn)對于鋅同位素測試,濃度效應與酸度效應影響都較大,在進行鋅同位素組成分析時需進行匹配。初步探討了鋅對銅同位素分析結(jié)果的影響,具體包括鋅濃度對測試值的影響,鋅對銅同位素分析時的濃度效應和酸度效應影響。2.初步研究了 NIST SRM 682作為標準樣品對NIST SRM 683的長期穩(wěn)定值,所得結(jié)果為δ66Zn=0.12±0.03%‰,與前人測試結(jié)果一致,同時分析了 CAGS-Zn相對于NISTSRM 682的值,并經(jīng)計算轉(zhuǎn)化為參考標準為JMCZn的值,結(jié)果為δ66ZZn=-0.75±0.09%‰,與報道一致,證明以SRM682為實驗室內(nèi)部標準是可行的。3.開發(fā)了快速分離方法,通過通入氣體的方式達到提高分離效率的目的。以銅同位素為例研究了不同氣體流量對分離的影響,確定了 20mL/min流量作為合適的氣流條件,該條件下回收率達到99.95%,同時將分離時間縮短為原來的50%,極大的提高了分離效率。對該條件下對不同分離階段的影響做了實驗探究,證明了在清洗和平衡樹脂階段使用該方法能夠在保證分析結(jié)果正確的情況下提高分離效率。4.將快速分離方法應用于Sr,Nd同位素的分離上,通過對不同分離階段下通入氣體對Sr,Nd分離的影響研究,得出了加速分離方法同樣適用于Sr,Nd樣品的分離過程。一次分離時將分離效率提高2倍,二次分離時則使分離效率提高1.2倍。
[Abstract]:Due to the various applications of zinc in mineralization, life activities and modern industry, It is of great significance to study the composition of zinc isotopes. However, the failure of zinc isotope analysis methods to determine the accepted reference standards greatly affects the comparison of laboratory data and the analysis and testing of other actual samples. The analysis speed of plasma mass spectrometry is fast, Because of its high sensitivity, this method has been widely used in isotope analysis. However, the method requires strict pretreatment of samples, and the separation and purification time of samples is long and the efficiency is low, which restricts the application of the analytical method. Therefore, it has become an urgent need to improve the pretreatment efficiency of samples. In this paper, a high precision analytical method for the determination of zinc isotopes by multi-receiving plasma mass spectrometry has been studied, and a rapid isotope separation method has been developed, and copper and strontium have been used for the determination of zinc isotopes. The method of neodymium isotope separation is used as an example to verify its reliability. The main research contents are as follows: 1. To determine the dissolution of zinc isotopic sample, separation method and analytical test method. AG1-X8 strong basic anion exchange resin is used for separation. The separation process is relatively short and can reduce the introduction of background, and the recovery rate is 99.33. The zinc isotope is analyzed and tested by MC-ICP-MS, the parameters of the instrument are optimized, and the influence of different sampling methods on the analysis results is analyzed. The experimental results show that the dry sample injection with membrane stripping device has more advantages, the accuracy of the analysis results is higher, and the amount of sample is less. The concentration effect and acidity effect of zinc isotopic test are analyzed, and it is found that the concentration effect and acidity effect are significant for zinc isotope test. The effect of zinc on the results of copper isotopic analysis was preliminarily discussed, including the effect of zinc concentration on the measured values. The effect of zinc on the concentration and acidity of copper isotopic analysis. 2. The long-term stable value of NIST SRM 682 for NIST SRM 683 was studied. The result is 0. 12 鹵0.03% 鈥，

本文編號：1600144