Errors in Isotope Dilution Caused by Matrix-induced Mass Bias Effect in Quadrupole Inductively Coupled Plasma-Mass Spectrometry

• Published in: Bulletin of the Korean Chemical Society Vol. 35; no. 12; pp. 3482 - 3488
• Main Author: Pak, Yong-Nam
• Format: Journal Article
• Language: English
• Published: 대한화학회 20.12.2014
• Subjects: 화학
• ISSN: 0253-2964; 1229-5949
• DOI: 10.5012/bkcs.2014.35.12.3482

Matrix-induced mass bias and its effect on the accuracy of isotope ratio measurements have been examined for a quadrupole-based inductively coupled plasma-mass spectrometer (Q ICP-MS). Matrix-induced mass bias effect was directly proportional to % mass difference, and its magnitude varied for element and nebulizer flow rate. For a given element and conditions in a day, the effect was consistent. The isotope ratio of Cd106/Cd114 under 200 μg g−1 U matrix deviated from the natural value significantly by 3.5%. When Cd 111 and Cd114 were used for the quantification of Cd with isotope dilution (ID) method, the average of differences between the calculated and measured concentrations was −0.034% for samples without matrix (0.076 μg g−1 to 0.21 μg g−1 for the period of 6 months). However, the error was as large as 1.5% for samples with 200 μg g−1 U. The error in ID caused by matrix could be larger when larger mass difference isotopes are used. KCI Citation Count: 4