Determination of Ge, As and Se in nickel-based alloys by flow injection hydride generation dynamic reaction cell inductively coupled plasma mass spectrometry

A dynamic reaction cell™ inductively coupled plasma mass spectrometry (DRC-ICP-MS) method has been developed for the determination of Ge, As and Se in nickel-based alloys using flow injection hydride generation as the sample introduction system. The hydride generation technique alleviated the matrix-based interferences, such as 58Ni16O+, 59Co16O+ and 62Ni16O+, on the determination of 74Ge+, 75As+ and 78Se+. L-Cysteine is used as a masking agent to reduce the interferences arising from the transition metals. By using H2 as the reactive cell gas in the DRC, the interferences arising due to the formation of 35Cl37Cl+, 37Cl37Cl+, 40Ar35Cl+ and 38Ar40Ar+ on the determination of 72Ge+, 74Ge+, 75As+ and 78Se+ have also been alleviated. The effects of the operating conditions of the hydride generation and DRC system have been studied to select the best signal-to-background ratio (S/B). Validation of the method is carried out by determining Ge, As and Se in standard reference materials of nickel-based alloys (NIST SRM 897–899). The concentrations of Ge, As and Se have been determined by standard addition and/or isotope dilution methods. The Se experimental results agreed satisfactorily with the certified values, and that of Ge and As with reference values obtained by pneumatic nebulization using high resolution ICP-MS. The detection limits for Ge, As and Se were in the range 0.001, 0.001 and 0.02 ng ml−1, respectively, which corresponds to 1–20 ng g−1 in the original alloy samples. The precision between sample replicates was better than 6% for all the determinations.