Evaluation of a Cu–Ni laminated sampler cone for ICP-MS: comparison of figures of merit with a conventional system

Abstract

This study compares analytical figures of merit of a normal standard sampler cone with those obtained using a new Cu–Ni laminated cone (Plasmaform). The short-term sensitivities of the Plasmaform cone are about 30–40% lower but Na-induced signal suppressions are distinctly smaller than the normal cone, resulting in superior long-term stability. Suppression was dependent on analyte mass and is considered to be mainly due to salt deposition on cones and not on shifts in ion–atom equilibrium. In the case of the Plasmaform sampling cone, lower sensitivity and improved long-term precision, and response to solutions containing up to 500 mg l⁻¹ NaCl, may be attributed to the smaller orifice diameter. The possibility of less material passing through the cone and falling on the skimmer could account for these observations. It is concluded that the Plasmaform Cu–Ni laminated sampler cone is more robust than a conventional cone. Because the salt-barrier appears to be less prominent in the case of the Plasmaform cone, it is concluded that this Cu–Ni laminated sampler cone is more robust and efficient for analysis of geo-environmental samples.