Behaviour of arsenic and selenium in an ICP-QMS with collision and reaction interface

The performance of a collision reaction interface (CRI) for minimization of spectral interferences on analytical signals of (75)As(+) and (76)Se(+), (77)Se(+), (78)Se(+), (80)Se(+) and (82)Se(+) isotopes was evaluated by using H(2) and He gases introduced through the sampler or skimmer cones of an inductively coupled plasma quadrupole mass spectrometer (ICP-QMS). Different gas flow rates were tested employing reference solutions prepared either in hydrochloric acid or in water soluble tertiary amines (CFA-C) media as carbon source. A hydrogen gas flow rate at 60 mL min(-1) introduced through skimmer cone was effective for minimizing polyatomic interferences on (75)As(+) and Se isotopes, except for (80)Se(+). The use of He introduced through sampler or skimmer cones had a minor effect on the minimization of interferences when compared to the use of H(2) gas. Moreover, it was observed that the gas introduction through the sampler cone had no effect on interferences when using gas flow rates up to 80 mL min(-1) for both gases evaluated. Based on these results, it can be recommended to use H(2) gas introduced through skimmer cone of the CRI for correcting polyatomic interferences on (75)As(+) and Se isotopes in matrixes containing up to 2% v v(-1) chloride.