STUDY ON THE ISOTOPE DILUTION –INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY (ID-ICP-MS) FOR DETERMINING 87Sr/ 86Sr ISOTOPIC RATIO IN PETROLEUM DRILLHOLES WATER SAMPLES

Abstract

87Sr/86Sr isotopic ratio is one of the useful tools that can authenticate the original source of the natural products from the earth-created and/or geological processes. However, the effect of the interferences such as thickness of sample matrix or isotopic signal of 87Rb might cause the low precision of 87Sr/86Sr
determination using quadrupole inductively coupled plasma spectrometry (ICP-MS). With the assistance of the isotope dilution technique using enriched 86Sr isotope standard solution for the control of separation process, the 87Sr/86Sr isotopic ratio was sucessfully determined using ICP-MS together with the signal correction by a strontium isotopic ratio standard reference material (NIST SRM 987). The proposed analytical procedure can thus be applied for the determination of 87Sr/86Sr isotopic ratio in the petroleum drillholes water samples with the acceptable precision and the relatively high accuracy