本文選題：Fe同位素 + 化學(xué)分離　； 參考：《西北大學(xué)》2017年碩士論文

【摘要】：本文利用大型多接收等離子體質(zhì)譜(Nu Plasma 1700 MC-ICP-MS,NP-1700)建立了溶液進(jìn)樣和飛秒激光剝蝕進(jìn)樣測(cè)試地質(zhì)樣品中Fe同位素組成的分析方法,并研究了二里河鉛鋅礦礦床的Fe同位素組成特征。主要的研究?jī)?nèi)容包括:進(jìn)一步完善了地質(zhì)樣品的化學(xué)溶解方法,改進(jìn)了 Fe同位素的分離純化流程;建立了溶液進(jìn)樣MC-ICP-MS準(zhǔn)確測(cè)定地質(zhì)樣品中Fe同位素組成的測(cè)試方法,研究了儀器條件(錐組合、進(jìn)樣方式)和樣品條件(酸度效應(yīng)、濃度效應(yīng))對(duì)Fe同位素組成測(cè)定的影響;綜合Ni內(nèi)標(biāo)法與SSB法(標(biāo)準(zhǔn)-樣品交叉法)校正質(zhì)譜質(zhì)量歧視效應(yīng),研究了 Fe/Ni信號(hào)比對(duì)Fe同位素測(cè)試的影響;利用本研究所建立的化學(xué)處理方法及分析方法,測(cè)試了部分國(guó)際標(biāo)準(zhǔn)巖石樣品的Fe同位素組成,分析結(jié)果與文獻(xiàn)報(bào)道值在2s誤差范圍內(nèi)完全一致,證明了所建立方法的可靠性;同時(shí),基本建立了原位微區(qū)分析Fe同位素的方法,并利用所建立的方法分析了兩個(gè)天然黃鐵礦的Fe同位素組成,與溶液法所得結(jié)果在誤差范圍內(nèi)完全一致。1.在前人研究的基礎(chǔ)上,進(jìn)一步完善了地質(zhì)樣品的化學(xué)溶解方法,改進(jìn)了 Fe同位素的分離純化流程,用HF和HNO3(體積比3:1)可以完全溶解大部分地質(zhì)樣品,之后轉(zhuǎn)為HC1介質(zhì)待化學(xué)分離;利用AGMP-1M陰離子交換樹(shù)脂分離純化Fe同位素,依次用2、4、8mol/LHCl清洗樹(shù)脂,提高了回收率(大于99%),所建立化學(xué)方法的全流程Fe 本底7ng。2.利用NP-1700的高分辨模式(M/△ M=14,000 RP)將Fe同位素的多原子離子干擾譜峰(如:[40Ar14N]+、[40Ar160]+等)與Fe同位素信號(hào)完全分離,分別采用濕法和干法進(jìn)樣對(duì)部分國(guó)際標(biāo)準(zhǔn)全巖粉末樣品的Fe同位素組成進(jìn)行了測(cè)定,在2s誤差范圍內(nèi),兩種進(jìn)樣方式的分析結(jié)果與文獻(xiàn)參考值完全一致,且濕法進(jìn)樣δ56Fe的測(cè)量精度優(yōu)于0.029‰,而干法進(jìn)樣δ56Fe的測(cè)量精度優(yōu)于0.084‰。通過(guò)條件實(shí)驗(yàn)研究表明:濕采樣錐+濕截取錐組合的儀器穩(wěn)定性最好,樣品和標(biāo)樣需要進(jìn)行嚴(yán)格的HNO3介質(zhì)酸度匹配,而Fe的濃度無(wú)需嚴(yán)格的匹配,Ni內(nèi)標(biāo)結(jié)合SSB法校正儀器質(zhì)量歧視可以顯著提高測(cè)試的穩(wěn)定性。3.基本建立原位微區(qū)分析單礦物中Fe同位素的方法,探索了激光剝蝕斑束和頻率對(duì)Fe同位素測(cè)試影響,并利用所建立的方法分析了兩個(gè)天然黃鐵礦的Fe同位素組成,化學(xué)法所得結(jié)果在2s誤差范圍內(nèi)完全一致。4.利用本文建立的方法分析了二里河鉛鋅礦硫化物閃鋅礦、磁黃鐵礦、黃銅礦和黃鐵礦中的Fe同位素組成,對(duì)該礦床的Fe同位素特征進(jìn)行了初步討論。
[Abstract]:In this paper, using Nu Plasma 1700 MC-ICP-MSNP-1700, an analytical method for the determination of Fe isotopic composition in geological samples by solution injection and femtosecond laser ablation has been established, and the characteristics of Fe isotopic composition of the Erlihe Pb-Zn deposit have been studied. The main research contents are as follows: the chemical dissolution method of geological samples has been further improved, the separation and purification process of Fe isotopes has been improved, and a method for the accurate determination of Fe isotopic composition in geological samples by solution injection MC-ICP-MS has been established. The effects of instrument conditions (cone combination, sample injection) and sample conditions (acidity effect, concentration effect) on the determination of Fe isotopic composition were studied, and the mass discrimination effect of mass spectrometry was corrected by combining Ni internal standard method and SSB method (standard sample cross method). The influence of Fe / Ni signal ratio on Fe isotope measurement was studied, and the Fe isotopic compositions of some international standard rock samples were measured by the chemical treatment method and the analytical method established in this paper. The analytical results are consistent with the reported values in the range of 2s, which proves the reliability of the established method, and establishes the method of in situ microanalysis of Fe isotopes. The Fe isotopic compositions of two natural pyrites are analyzed by using the established method. The results are in good agreement with the results obtained by the solution method within the error range. On the basis of previous studies, the chemical dissolution method of geological samples is further improved, and the separation and purification process of Fe isotopes is improved. Most geological samples can be completely dissolved by HF and HNO _ 3 (volume ratio 3:1). The iron isotopes were purified by AGMP-1M anion exchange resin, and then washed with 2o 4 mol / L HCl, the recovery rate was increased (> 99%), and the whole process of Fe background was 7ng.2. The interference spectra of polyatomic ions (such as [40Ar14N], [40Ar160]) of Fe isotopes are completely separated from Fe isotopic signals by NP-1700 high resolution mode (M / M14000 RP). The Fe isotopic compositions of some international standard whole rock powder samples were determined by wet and dry injection, respectively. Within the error range of 2 s, the analytical results of the two injection methods are in full agreement with the reference values in the literature. The measurement accuracy of wet sampling 未 56Fe is better than 0.029 鈥，

本文編號(hào)：2110544