Ultra-high Precision Determination of ~(142)Nd/~(144)Nd Ratio Using Thermal Ionization Mass Spectrometry
Ultra-high precision determination of 142Nd/144Nd ratio has important application value for the research of early evolution of the Solar system and early silicate differentiation of the Earth and the Moon.We utilize thermal ionization mass spectrometry (TIMS) to perform ultra-high precision determination of 142Nd/144Nd in the first time in China and compare both multi-dynamic mode and multi-static mode.The results show that multi-dynamic mode is much higher accuracy and precision than multi-static mode.All influencing factors on the determination were discussed and optimized.142Nd/144Nd isotopic ratio of international standard Jndi-1,whose external precision is better than 5×10-6 (2SD),is 1.1418348 and the precision is completely satisfied to technical requirements of 146Sm-142Nd system.