Capillary electrophoresis analysis of biofluids with a focus on less commonly analyzed matrices

The analysis by capillary electrophoresis of less commonly analyzed biofluids is reviewed. The sample matrices considered include airway surface fluid, sputum, synovial fluid, amniotic fluid, saliva, cerebrospinal fluid, aqueous humor, vitreous humor, and sweat. Many of the techniques used in the analysis of abundant and commonly tested biofluids such as plasma or urine can be applied to these other matrices, e.g. sample extraction prior to analysis. However, for some of these alternative biofluids the available sample amounts are only in the nanoliter or low microliter range, which places constraints on the sample preparation options which are available. For such samples, direct sample injection may be necessary, possibly coupled with on-capillary concentration or derivatization approaches. Particular attention is paid in this review to analyses where the sample is directly injected onto the separation capillary or where minimal sample preparation is performed.