Determination of Ni by ICP-MS: Correction of Calcium Oxide and Hydroxide Interferences Using Principal Components Analysis

Publisher Website
Google Scholar
Abstract
Determination of Ni by ICP-MS is hampered by the overlap of Ca oxides and hydroxides with each of the major isotopes of Ni. This is problematic in biological fluids with high Ca:Ni ratios, such as urine, and is worsened by other interferents such as NaK that arise from a urine matrix. These problems have been overcome by using principal components analysis to separate Ni information. This approach allows determination of Ni in Ca solutions and urine. In addition the method can be used to separate Ni information from two distinct sources (for example, naturally abundant and isotopically enriched Ni) in the presence of Ca. Limits of detection of approximately 1 ng/mL for naturally abundant Ni and for a 62Ni enriched source were determined in a matrix of 40% urine.