Suitable interface for coupling liquid chromatography to inductively coupled plasma-mass spectrometry for the analysis of organic matrices. 2 Comparison of Sample Introduction Systems

•31 interfaces are compared for the coupling of LC and ICP-MS/MS.•The extra-column variance varies from 6 to 8000 μL² depending on the interface.•Solute dispersion is proved to be a major issue for most commercial interfaces.•The effect of flow-rate and spray chamber temperature is highlighted. Liquid chromatography (LC) coupled with a specific detection such as inductively coupled plasma-mass spectrometry (ICP-MS/MS) is a technique of choice for elementary speciation analysis for complex matrices. The analysis of organic matrices requires the introduction of volatile solvents into the plasma which is an analytical challenge for this coupling technique. Detection sensitivity can be significantly affected by instrumental limitations. Among those, we were interested in the solute dispersion into the interface located between LC and ICP-MS/MS. This interface consists in both a Sample Introduction System (SIS) and a possible flow splitter. This study, divided into two parts, investigated the analytical performance (in terms of sensitivity and efficiency) generated by the coupling of LC and ICP-MS in the specific case of organic matrices. In Part I [1], we previously discussed the impact of extra column dispersion on the performance of LC-ICP-MS, first from a theoretical point of view and next, by assessing extra-column dispersion in 55 published studies on LC-ICP-MS. It was shown that SIS was rarely optimized with respect to its contribution to extra-column band broadening. The critical impact of flow splitting on extra-column dispersion was also pointed out. The present Part II is dedicated to the experimental comparison of commercially available SIS by assessing extra-column band broadening and hence the contribution of SIS to the loss in both efficiency and sensitivity. It is shown that the peak variance, due to SIS, can vary from 10 to 8000 μL² depending on the combination of both nebulizer and spray chamber. Whereas the highest values (i.e. > 2000 μL²) are much too high in high performance liquid chromatography (HPLC), even the lowest values (i.e.