微量碳酸钙中￣（13）C和￣（18）O的质谱分析

Mass Spectrometric Analyses of￣13Cand￣18O at Microgram Levels of Calcium Carbonate

本工作研制了一套用于有孔虫等微量碳酸钙样品（５０～１００μｇ）中碳、氧同位素质谱分析的磷酸法转化装置。采用磁力进样法，可连续进行２５个样品的转化。在ＶＧＳＩＲＡ－２４气体同位素质谱计上测量，分析的标准偏差对δ￣１３ｃ和δ￣１８Ｏ分别在±０，２％和±０．３％以内。

A manual conversion device for microgram level samples(50～100μg)of cal- cium carbonate on benthic foraminifes isotope analyses have been developed for pale- oenviroment stud y,Twenty five samples can be loaded for reaction with 100% or- thophosphoric acid continuously one after another in a vacuum system。 The standard diviations of measurements on VG SIRA-24 MS are within 0.2‰ for δ￣13Cand 0.3‰ for δ￣18O。