Effects of Acid and Concentration on Cu and Zn Isotope Measurements by Multicollector-Inductively Coupled Plasma Mass Spectrometry
The effects of acid and its concentration on instrumental mass discrimination are issue which has not been investigated so far,although adequate understanding of the factors affecting the mass discrimination is essential for mass bias correction during isotopic measurements using the MC-ICP-MS.The results show that the acidity of HNO3 has significant effects on instrumental mass discrimination for Cu and Zn isotopes,but with different degrees for the two elements.No effect has been observed when the measurements were performed using HCl medium to certain extend of concentration variation from 0.05-0.30 molL.Thus it is proposed that HCl is a better medium than NHO3 for sample introduction for Cu and Zn isotope measurements using MC-ICP-MS.The repeatabilities for both65Cu63Cu and66Zn64Zn measurements in 0.1 molL HCl solution are both 0.00008(2sd),which are better than those in HNO3.