Electrolyte system strategies for anionic isotachophoresis with electrospray-ionization mass-spectrometric detection. 1. Regular isotachophoresis and free-acid isotachophoresis.
The subject of this work is the definition of a simple model based on general ITP theory that allows describing and predicting the behavior of ITP systems compatible with ESI-MS detection. The model is exemplified by anionic ITP of weak acids that represent an interesting potential application field of ITP-ESI-MS. Suitable ESI-compatible electrolyte systems of very simple composition are proposed including a special free-acid ITP arrangement. The properties of these systems are discussed using illustrative diagrams of their stacking windows. The use of anionic ITP-ESI-MS in negative-ion ESI mode is reported for the first time and its suitability for sensitive trace analysis is demonstrated. The presented ITP-ESI-MS application example comprises a free-acid ITP system formed of formic and propionic acids and direct injection analysis of ibuprofen and diclofenac in waters with quantitation limits of the order 10(-10) M.
Institute of Analytical Chemistry, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
Zdena
Z
Malá
Petr
P
Gebauer
Petr
P
Boček
D000143:Acids / Q000737:chemistry; D018712:Analgesics, Non-Narcotic / Q000032:analysis*; D000838:Anions / Q000737:chemistry; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000032:analysis*; D004008:Diclofenac / Q000032:analysis*; D060766:Drinking Water / Q000032:analysis*; D004573:Electrolytes / Q000737:chemistry; D019075:Electrophoresis, Capillary; D007052:Ibuprofen / Q000032:analysis*; D057625:Isotachophoresis / Q000379:methods*; D057230:Limit of Detection; D045483:Rivers / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D000143:Acids; D018712:Analgesics, Non-Narcotic; D000838:Anions; D000894:Anti-Inflammatory Agents, Non-Steroidal; D060766:Drinking Water; D004573:Electrolytes; D004008:Diclofenac; D007052:Ibuprofen
Diclofenac; ESI-MS detection; Ibuprofen; Isotachophoresis; Water analysis