Use of FIA systems for on-line dilution in multielement determination by ICP-MS

A flow-injection (FI) system to match concentrations was used as an auto-di luter in multielement determination by inductively coupled plasma-mass spec trometry (ICP-MS). The flow system comprised loop-based injection or a time d valve that introduced a variable sample volume info a spray chamber throu gh a standard Meinhard nebulizer of an ICP-MS. Routinely analyzed samples s uch as water, plant, and steel were selected. The accuracy of multielement determination was checked against water standard reference material from th e National Institute of Standards and Technology (1643d), plant standard re ference material from the National Bureau of Standards (1572 citrus leaves) , and steel standard reference material from the National Bureau of Standar ds (AISI 4340). The measuring system was calibrated with a multielement sol ution, yielding a linear plot with good precision [relative standard deviat ion (RSD) < 3%, n = 12]. The results were in agreement at a 95% confidence level with the certified values for the reference materials and also with t hose obtained by continuous aspiration and by (FI) with a discrete volume. (C) 1999 John Wiley & Sons, Inc.