高精度热电离质谱法测定氯同位素

High Precision Isotopic Measurement of Chlorine by Thermal Ionization Mass Spectrometry

中文关键词:  氯 同位素 测定 正热电离 质谱法

英文关键词:Isotopic measurement, Thermal ionization,

中文摘要:

      本文首次建立了基于Cs_2Cl~+离子的高精度正热电离质谱测定氯同位素的方法,发现石墨的存在能大大增强Cs_2Cl~+离子的发射强度和稳定性。实验中对影响测定精度的各种因素,如样品液的pH值、涂样量、样品蒸干条件、分馏效应等进行了较为详细的研究,测定了光谱纯HCl试剂中的~(37)Cl/~(35)Cl同位素比值,精度为0.034％(95％置信水平),用此法还初步研究了盐湖卤水中的氟同位素组成。

英文摘要:

      A procedure for determination of chlorine isotopic ratios by the positive thermal ionization mass spectrometry of the Cs_2Cl~+ ion has been investigated. The intensity of Cs_2Cl~+ emitted from CsCl is considerably enhanced by the addition of graphite to the filament substrate during the loading. Optimal conditions for measurement have been established. The chlorine isotopic compositions in HCl reagent has been measured with a precision of 0.0340%. The chlorine isotopic compositions in brines sample of salt lake have also been determined.