Biomedical Engineering – From Theory to Applications

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Biomedical Engineering – From Theory to Applications
A comparison of two types of CE instrumentation, single CZE and commercially available
ITP-CZE, used for the determination of hippuric acid in serum was demonstrated by
Křivánková et al. (Křivánková et al., 1997b). Results obtained in the single-capillary methods
(ITP and CZE) were comparable and were limited both by the sensitivity of the detector
used and by the load capacity of the system. This work pointed out decreasing of
concentration LOD (cLOD 7.10 -7 M was two-orders of magnitude lower by using ITP-CZE
method in comparison with single column CZE). The sample volumes that could be injected
using this combined technique were up to 10 3 orders of magnitude higher in the case of
natural biological samples than those that could be analyzed in a single capillary CZE
technique. Excellent reproducibility of migration times (R.S.D. less than 1%) and resistance
to changes in the matrix composition enabled the determination of HA in serum not only for
patients suffering from renal diseases but also for healthy individuals.
Fig. 16. (a) Conductivity trace of the analysis of 1L undiluted blood. LE: 10mM
ammonium acetate pH 7.8, TE: 20mM acetic acid pH 3.5. (b) Selected ion monitoring of
the ions in the ITP zones of undiluted blood. Reprinted from ref. (Tomáš et al., 2010), with
permission.