Using the Multimode Sample Introduction System™ (MSIS™) for Low Level Analysis of Arsenic and Selenium in Water.

In recent years, the problems associated with the measurement of low concentrations of arsenic (As) and selenium (Se) using conventional nebulization and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) have been largely overcome by using hydride generation. In 2002, a radically new design for the combined nebulizer/gas liquid separator referred to as the Multimode Sample Introduction System™ (MSIS™, Marathon Scientific, Niagara Falls, Ontario, Canada) was introduced. The feasibility and detection limits of combining the MSIS™ with a Spectro Ciros CCD (axial) ICP-AES for the determination of low concentrations of As and Se in water were examined. Overall, the system was inexpensive, easy to install, accurate and precise, and lowered the quantification limits by approximately 100-fold for As and by 20-fold for Se as compared to a conventional nebulization.  Unlike other conventional hydride generators, the MSIS™ does not need to be removed from the ICP when analyzing other elements without the need of hydride generation. Therefore, the MSIS™ is recommended to laboratories seeking low detection limits for As and Se with existing or new ICP instruments.