Investigation of helium inductively coupled plasma-mass spectrometry for the detection of metals and nonmetals in aqueous solutions

A status report on helium inductively coupled plasma mass spectrometry

“…Mass spectral interferences resulting from argon polyatomic species are reduced when He-based plasmas are applied as ionization sources, because He essentially is monoisotopic, and occurs at a low mass [11,12,20,24,25,27,30,35,36,[39][40][41][42]. The three isotopes of Ar ( 36 Ar + , 38 Ar + , and 40 Ar + ) along with polyatomic species containing Ar such as 40 Ar 16 O + , 40 Ar 40 Ar + , 40 Ar 35 Cl + interfere with the determination of certain isotopes, e.g.…”

“…The smaller size of He ICP and smaller electrical conductivity of helium lead to higher electric fields [46]. The presence of a high electric field in He ICP can lead to an undesirable secondary discharge to the MS interface [20,24,25,47,49]. In short, interface-linked discharges are very strong when the He ICP is used instead of the Ar ICP as an ionization source for mass spectrometry, even for the injection of gaseous samples into the plasma [20].…”

“…In short, interface-linked discharges are very strong when the He ICP is used instead of the Ar ICP as an ionization source for mass spectrometry, even for the injection of gaseous samples into the plasma [20]. Importantly, techniques often used to reduce or eliminate the secondary discharge in Ar ICPMS have not been applicable thus far to He ICPMS [24,25,47].…”

“…In our earlier paper [24], we reported on the first investigation of He ICPMS for detection of metals and nonmetals in aqueous solutions. In general, the limits of detection measured for the nonmetals in a 800-W He ICP were the same or better than those for the Ar ICP [24,25].…”

Fundamental studies of the plasma extraction and ion beam formation processes in inductively coupled plasma mass spectrometry

“…He ICP have been investigated as an alternative ion source for analytical mass spectrometry (198)(199)(200) (194,197). To sustain a He ICP and interface to mass analyzer, some modifications of the load coil, plasma torch and impedance network are necessary.…”