Dynamic reaction cell inductively coupled plasma mass spectrometry for determination of silicon in steel

An inductively coupled plasma quadrupole mass spectrometer (ICP-QMS) equipped with a dynamic reaction cell™ (DRC) was used for the determination of silicon in steel samples. The effect of the operating conditions of the DRC system was studied to get the best signal-to-noise ratio for 28Si. The intensity of potentially interfering ions 12C16O+ and 14N14N+ at the silicon mass m/z 28 were reduced significantly by using NH3 as the reaction cell gas in the DRC. The signal-to-background ratio was improved more than one order by using the DRC system. Validation of the method was carried out by the determination of silicon in steel standard reference materials (NIST SRM 15h and SRM 368). Good agreement was obtained between the certified values and the experimental results. The accuracy was better than 3% for all the determinations. The detection limit for silicon was in the range of 0.2 ng ml−1 which corresponds to 2 μg g−1 in the original sample. The precision (R.S.D.) between sample replicates was better than 5% for all the determinations.