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Direct measurement of lithium in whole blood using microchip capillary electrophoresis with integrated conductivity detection
Author(s) -
Vrouwe Elwin X.,
Luttge Regina,
van den Berg Albert
Publication year - 2004
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200405885
Subject(s) - electropherogram , capillary electrophoresis , electrokinetic phenomena , chromatography , electrophoresis , whole blood , lithium (medication) , chemistry , detection limit , capillary action , analytical chemistry (journal) , microchannel , materials science , nanotechnology , medicine , immunology , composite material , biology , endocrinology
The direct measurement of lithium in whole blood is described. Using microchip capillary electrophoresis (CE) with defined sample loading and applying the principles of column coupling, alkali metals were determined in a drop of whole blood. Blood collected from a finger stick was mixed with anticoagulant and transferred onto the chip without extraction or removal of components. The electrokinetic transport of red blood cells inside the channels was studied to find sample loading conditions suitable for the analysis of lithium without injecting cells into the separation channel. Both bare glass chips and chips coated with polyacrylamide were used showing the behavior of the cells under different electroosmotic flow conditions. In serum a detection limit for lithium of 0.4 mmol/L was reached. Proteins quickly contaminated untreated chip surfaces but devices with coating gave reproducible electropherograms. In addition, potassium and sodium were also detected in the same separation run. To our knowledge, this is the first device to directly measure ions in whole blood with the use of capillary zone electrophoresis on a microchip.