On-line dilution, steady-state concentrations for inductively coupled plasma atomic emission and mass spectrometry achieved by tandem injection and merging-stream flow injection

Abstract

Steady-state concentrations have been achieved by on-line dilution, flow injection techniques with conventional instrumentation. An approach employing tandem injection for on-line dilution was applied to obtain a steady-state concentration. The deviation from signal stability resulting from concentration variations or ripples hampered exploitation of this approach for on-line dilution except over a limited range. However, when tandem injection was coupled with a single-or, especially, a double-confluence for the diluent, dilution was achieved over a wide range (up to 900-fold). Further, steady-state concentrations were obtained without concentration ripples. With the combined tandem injection and merging stream the emission signal variation with inductively coupled plasma (ICP) spectrometry compares well with that obtained for direct sample nebulisation. Simple relationships for calculation of the anticipated dilution have been derived and validated experimentally. Flow configurations were designed to implement on-line dilution approaches under optimum conditions. Although these developments for on-line dilution are initially intended for sequential multi-element ICP spectrometric analysis, they should prove to be of general use.

Multi-commutation in flow analysis: Recent developments and applications

“…(a) Not pertinent; (b) not informed. a n a l y t i c a c h i m i c a a c t a 6 1 8 ( 2 0 0 8 ) [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] high and tends to increase. The authors apologize for any relevant contribution omitted.…”

“…sample stopping, random access reagent selection, individual sample conditioning, and exploitation of concentration-oriented feedback mechanisms can be exploited simply by modifying the time course related to operation of these devices or by allowing their automated adjustment [2]. Moreover, tandem streams [1,[3][4][5][6] are efficiently implemented. This unique stream comprises initially "several neighboring small plugs of miscible solutions that undergo fast mixing while flowing through the analytical path" [7].…”

Informações essenciais para a caracterização de um sistema de análise em fluxo

“…As dimensões do elemento de injeção (e.g. : comprimento de uma alça externa), tempo de injeção e outras características específicas de injeção (simultânea 36,37 , seqüencial 38,39 , com divisão de amostra 36 , múltipla 40 , tandem [41][42][43][44] , hidrodinâmica 45 , "nested" 46 [n.t. : injeção baseada em várias seqüências (volume) ou intervalos (tempo).…”

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

“…FIA techniques have been coupled to flame atomic absorption spectrometry (FAAS) [15][16][17], inductively coupled plasma atomic emission spectrometry (ICP-AES) [18,19], and ICP-MS [18,19] to achieve on-line dilution. Until now, few workers have attempted to apply this approach to ICP-MS multielement analysis.…”