Two simple interface designs for capillary electrophoresis–inductively coupled plasma mass spectrometry†

Abstract

The design and implementation of two different interfaces for capillary electrophoresis-inductively coupled plasma mass spectrometry (CE-ICP-MS) are described. These interfaces will allow for on-line analysis of CE effluents with ICP-MS detection. One interface is based on a concentric tube nebulizer and the other on a standard cross-flow nebulizer. These systems were investigated in parallel and their performances, under various experimental conditions, were compared. Each interface possesses a unique set of advantages and shortcomings. Recognizing that typical sample flow rates for ICP-MS are of the order of ml min 21 and that the flow rates for CE are a few nl min 21 , some difficulties in flow compatibility are encountered. Aspects discussed include interface considerations, flow compatibility and the influence of flow rates on the overall sensitivity. Several guidelines are provided for workers interested in implementing a CE-ICP-MS instrument for elemental speciation. The Cd detection limits in rabbit metallothionein were 2.36 and 0.21 mg ml 21 for the concentric and cross-flow nebulizers, respectively.

Eletroforese capilar acoplada à espectrometria com plasma: uma ferramenta eficiente para a especiação

“…Um recurso utilizado para implementar a interface CE-ICP-MS é a introdução do capilar no interior do nebulizador. Vários tipos de interface, feitas nos próprios laboratórios de pesquisa, empregando nebulizadores concêntricos [26][27][28][29][30] e micro-concêntrico [31][32][33][34] , de injeção direta 35 (DIN: Direct Injection Nebulizer), dealta eficiência 27 (HEN: High Efficient Nebulizer) e ultra sônico 36 , têm sido propostos. Dentre esses, o HEN é o mais adequado para as micro-amostragens necessárias para os acoplamentos com HPLC, CE e FIA (FIA: Flow Injection Analysis) ou mesmo para conseguir maior freqüência analítica.…”

“…Majidi e Miller-Ihli 28 utilizaram uma interface com um nebulizador concêntrico, cuja vazão de gás era mínima para evitar a perda de resolução. Contudo, ao utilizar uma vazão do gás de nebulização menor que a ótima, a sensibilidade poderia ser afetada.…”

Determination of Compositions in Cosmetics by Multiple-Instrument

“…These methods have high sensitivity and low selectivity for detection of heavy metals; at the same time, most of these methods were used to determine the total amount of metal rather than the metal form. Majidi [13] and Gudzenko [15] reported the determination of methyl mercury and ethyl mercury, and Evans reported the determination of three forms of mercury including 3 CH  , 2 5 C H  and 6 13 C H  [7]. In addition, there is no report about determination of the heavy metal form and simultaneous detection of multi-components in cosmetics.…”

“…For example electrochemical detector detection (EC) [8], cold vapor atomic absorption spectrometry (CVAAS) [8,9], atomic emission spectroscopy (AES) [10], and inductively coupled plasma mass spectrometry (ICP-MS) [11,12], and so on. There are also some reports using capillary electrophoresis (CE) combining with inductively coupled plasma mass spectrometry (CE-ICPMS) [13,14] and capillary electrophoresis combining with UV-Vis detection for heavy metals speciation [15,16]. These methods have high sensitivity and low selectivity for detection of heavy metals; at the same time, most of these methods were used to determine the total amount of metal rather than the metal form.…”

“…In literature [7][8][9][10][11][12][13][14], there is no report about determination of the heavy metal form and this method established can analyze the form and content of heavy metal of cosmetic.…”