Advanced Capillary Electrophoresis Techniques in the Analytical Quantification of Drugs, Metabolites and Biomarkers in Biological Samples

Capillary electrophoresis offers several advantages in terms of higher chromatographic resolution, faster analysis, smaller sample volume required, lower cost due to very cheap capillaries (if compared to expensive HPLC or GC columns) and low organic solvent consumption. It is a powerful assay, in particular, applied to biological samples analyses (blood, urine, cerebrospinal fluid) and especially where a small amount of sample is available, such as pharmaceutical and biomedical analyses. For these reasons this technique is suitable to quantify drugs, metabolites and biomarker in biological fluid, where LOD and/or LOQ values at lower g/L range are required. In addition, under special condition, the technique can be applied also in presence of other sample constituents like protein or other macromolecules. The only limit of this method is represented by smaller sample volume that implies a relatively poor LODs values mainly caused by the small injection volume and when UV detection is used, the short optical path length attributable to the low inner diameter of the capillary. This review intends to explore the new frontiers of capillary electrophoresis techniques in terms of sensitivity improvement, bioanalytical (and pharmacological) applications, instrument configurations especially underlining its versatility and potentiality.