File(s) under permanent embargo
Polymeric microchip for the simultaneous determination of anions and cations by hydrodynamic injection using a dual-channel sequential injection microchip electrophoresis system
journal contribution
posted on 2014-01-01, 00:00 authored by Adam J Gaudry, Ryan Nai, Rosanne GuijtRosanne Guijt, Michael C BreadmoreA dual-channel sequential injection microchip capillary electrophoresis system with pressure-driven injection is demonstrated for simultaneous separations of anions and cations from a single sample. The poly(methyl methacrylate) (PMMA) microchips feature integral in-plane contactless conductivity detection electrodes. A novel, hydrodynamic "split-injection" method utilizes background electrolyte (BGE) sheathing to gate the sample flows, while control over the injection volume is achieved by balancing hydrodynamic resistances using external hydrodynamic resistors. Injection is realized by a unique flow-through interface, allowing for automated, continuous sampling for sequential injection analysis by microchip electrophoresis. The developed system was very robust, with individual microchips used for up to 2000 analyses with lifetimes limited by irreversible blockages of the microchannels. The unique dual-channel geometry was demonstrated by the simultaneous separation of three cations and three anions in individual microchannels in under 40 s with limits of detection (LODs) ranging from 1.5 to 24 μM. From a series of 100 sequential injections the %RSDs were determined for every fifth run, resulting in %RSDs for migration times that ranged from 0.3 to 0.7 (n = 20) and 2.3 to 4.5 for peak area (n = 20). This system offers low LODs and a high degree of reproducibility and robustness while the hydrodynamic injection eliminates electrokinetic bias during injection, making it attractive for a wide range of rapid, sensitive, and quantitative online analytical applications.
History
Journal
Analytical chemistryVolume
86Issue
7Pagination
3380 - 3388Publisher
ACS PublicationsLocation
Washington, D.C.Publisher DOI
eISSN
1520-6882Language
engPublication classification
C1.1 Refereed article in a scholarly journalCopyright notice
2014, American Chemical SocietyUsage metrics
Categories
No categories selectedKeywords
AnionsCationsElectrodesElectrolytesElectrophoresis, MicrochipHydrodynamicsMicrofluidicsPolymersReproducibility of ResultsSensitivity and SpecificityScience & TechnologyPhysical SciencesChemistry, AnalyticalChemistryCONTACTLESS CONDUCTIVITY DETECTIONPRESSURE PULSE INJECTIONCONTINUOUS SAMPLE FLOWCAPILLARY-ELECTROPHORESISMICROFLUIDIC CHIPSGLASS CHIPSPLANAR CHIPSEPARATIONDEVICES
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC