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Pressure‐assisted introduction of urine samples into a short capillary for electrophoretic separation with contactless conductivity and UV spectrometry detection
Author(s) -
Makrlíková Anna,
Opekar František,
Tůma Petr
Publication year - 2015
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.201400613
Subject(s) - chromatography , capillary action , capillary electrophoresis , chemistry , thermal conductivity detector , analytical chemistry (journal) , electrolyte , materials science , gas chromatography , electrode , composite material
A computer‐controlled hydrodynamic sample introduction method has been proposed for short‐capillary electrophoresis. In the method, the BGE flushes sample from the loop of a six‐way sampling valve and is carried to the injection end of the capillary. A short pressure impulse is generated in the electrolyte stream at the time when the sample zone is at the capillary, leading to injection of the sample into the capillary. Then the electrolyte flow is stopped and the separation voltage is turned on. This way of sample introduction does not involve movement of the capillary and both of its ends remain constantly in the solution during both sample injection and separation. The amount of sample introduced to the capillary is controlled by the duration of the pressure pulse. The new sample introduction method was tested in the determination of ammonia, creatinine, uric acid, and hippuric acid in human urine. The determination was performed in a capillary with an overall length of 10.5 cm, in two BGEs with compositions 50 mM MES + 5 mM NaOH (pH 5.1) and 1 M acetic acid + 1.5 mM crown ether 18‐crown‐6 (pH 2.4). A dual contactless conductivity/UV spectrometric detector was used for the detection.