title: Reduction of matrix effects in inductively coupled plasma mass spectrometry by flow injection with an unshielded torch.
abstract: Solution samples with matrix concentrations above approximately 0.1% generally present difficulties for analysis by inductively coupled plasma mass spectrometry (ICP-MS) because of cone clogging and matrix effects. Flow injection (FI) is coupled to ICP-MS to reduce deposition from samples such as 1% sodium salts (as NaCl) and seawater (approximately 3% dissolved salts). Surprisingly, matrix effects are also less severe during flow injection, at least for some matrix elements on the particular instrument used. Sodium chloride at 1% Na and undiluted seawater cause only 2 to 29% losses of signal for typical analyte elements. A heavy matrix element (Bi) at 0.1% also induces only approximately 14% loss of analyte signal. However, barium causes a much worse matrix effect, that is, approximately 90% signal loss at 5000 ppm Na. Also, matrix effects during FI are much more severe when a grounded metal shield is inserted between the load coil and the torch, which is the most common mode of operation for the particular ICP-MS device used.
authors.affiliation: Ames Laboratory-U.S. Department of Energy, Department of Chemistry, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Cory T
authors.initials: CT
authors.lastname: Gross
authors.forename: Sally M
authors.initials: SM
authors.lastname: McIntyre
authors.forename: R S
authors.initials: RS
authors.lastname: Houk