Systems and methods for detection and quantification of selenium and silicon in samples

A method for producing a stream of ions for detection and/or quantification of selenium (Se) in a sample, the method comprising:

• introducing a sample to an ionization source, thereby producing an ionized sample stream comprising a plurality of ionic species, said plurality of ionic species comprising:
• (i) one or more analyte ionic species, said one or more analyte ionic species being an ionized form of one or more species of interest present in the sample, said one or more species of interest comprising selenium, and said one or more analyte ionic species comprising Se+;
• and
• (ii) one or more interferer ionic species, said one or more interferer ionic species having nominal m/z substantially equivalent to that of Se+;
• admitting the ionized sample stream into a chamber to thereby contact the ionized sample stream with a reaction gas stream comprising CO2, thereby reacting the CO2 with at least one of the one or more interferer ionic species and producing one or more products that are not interferer ionic species;
• and
• following contact of the ionized sample stream with the reaction gas stream comprising CO2, directing the resulting product stream to a mass analyzer and detector for detection and/or quantification of selenium in the sample.