| Title: | Hyphenation of capillary high-performance ion-exchange chromatography with mass spectrometry using sheath-flow electrospray ionization |
| Address: | "Institute of Analytical Chemistry, University of Regensburg, Universitatsstr. 31, D-93053, Regensburg, Germany" |
| Journal Title: | Rapid Commun Mass Spectrom |
| ISSN/ISBN: | 1097-0231 (Electronic) 0951-4198 (Linking) |
| Abstract: | "RATIONALE: Mass spectrometry (MS) is an attractive method for extending capillary-size ion chromatography (cHPIC) to create a valuable technique for speciation analysis. For hyphenation, the aqueous effluent of cHPIC has to be transformed into a volatile mixture for MS while preserving analytical concentrations as well as peak shapes during transfer from cHPIC to MS. Finally, the approach should technically be flexible and easy-to-use. A combination of cHPIC and sheath-flow electrospray ionization (ESI)-MS offers to solve all these challenges. METHODS: cHPIC/sheath-flow-ESI-TOFMS was used in this study for the speciation analysis of various arsenic model compounds. These model compounds were analyzed with different hyphenation setups and configurations of cHPIC/MS and their respective assets and drawbacks were examined and discussed. The parameters (flow rate and composition of sheath liquid) of sheath-flow ESI and their influence on the performance of the spray and the sensitivity of the detector were investigated and compared with those of sheathless ESI. RESULTS: Using an injection valve to couple cHPIC and MS was found to be the best method for hyphenation, since it constitutes a flexible and dead-volume-free approach. The investigation of sheath-flow ESI revealed that the flow rate of the sheath liquid has to resemble the flow rate of the IC effluent to ensure a stable spray and that a composition of 2-propanol/water/ammonia at 50:50:0.2 (v/v/v) suits most applications without unilaterally promoting the sensitivity for either organic or inorganic compounds. The optimized setup and conditions were successfully applied to the analysis of a mixture of important arsenic species and used to determine limits of detection of organic and inorganic arsenic species (3.7 microg L(-1) elemental arsenic). CONCLUSIONS: A method for cHPIC/sheath-flow-ESI-MS was developed. The method was shown to be a valuable tool for speciation and trace analysis. It features no dead volume, fast transfer from IC to MS, only minimal peak-widening, high reproducibility, and the ability to fine-tune the ESI spray for higher sensitivity and stability by adjusting the composition of the sheath-liquid" |
| Keywords: | "2-Propanol/chemistry Ammonia/chemistry Arsenicals/analysis/chemistry Chromatography, Ion Exchange/*instrumentation/*methods Equipment Design Limit of Detection Models, Chemical Reproducibility of Results Spectrometry, Mass, Electrospray Ionization/*instru;" |
| Notes: | "MedlineKochmann, Sven Matysik, Frank-Michael eng Research Support, Non-U.S. Gov't England 2014/11/05 Rapid Commun Mass Spectrom. 2014 Dec 15; 28(23):2670-80. doi: 10.1002/rcm.7056" |
