High-Precision Measurements of 44 Ca/ 40 Ca Using Multiple-Collector Inductively Coupled Plasma Mass Spectrometry without Collision-Cell Technology

Herein, we present a new method for determining the Ca isotopic composition of geological samples. To eliminate matrix elements from Ca, a column chromatography method was developed using a , , ' ' tetraoctyl-1,5-diglycolamide (TODGA) resin. The Ca isotopic compositions were measured by a multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) without collision cell equipment, especially that direct measurement to Ca/ Ca can be achieved. To mitigate the interference from Ar during Ca measurement, the cold plasma technique was used to suppress the Ar generation, resulting in a background Ar intensity of