Versatile interface for gas chromatographic detection or solution nebulization analysis by inductively coupled plasma mass spectrometry: preliminary results

Abstract

An interface was designed and built which allowed the coupling of a gas chromatograph with an inductively coupled plasma (ICP) mass spectrometer while allowing aqueous solution nebulization with no instrumental re-configuration. The interface incorporates a switching T-valve with a sheathing device for the addition of the make-up gas to the chromatograph effluent. Dichloromethane, 1,1,1-trichloroethane and trichloroethylene were separated by gas chromatography and detected by monitoring the ³⁵Cl⁺ ion in the ICP mass spectrometer. The performance of the system was evaluated and detection limits of 2.6, 2.2 and 2.6 ng were obtained for CH₂Cl₂, H₃C–CCl₃ and HClC = CCl₂, respectively. The performance of the interface for direct solution nebulization was also assessed, while aspirating aqueous solutions (containing Al, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, Ga, As, Mo, Cd, Sb, La, Hg and Pb), both with and without the interface in place. With the exception of Zn, some degradation of detection limits was observed.