A miniaturized electrospray interface consisting of a microfluidic nanosprayer and nanospray module is reported in the presented short communication. The nanosprayer was fabricated using silicon (Si) technology suitable for cost-efficient high-volume mass production. The nanospray module enabled the positioning of the nanosprayer in front of a mass spectrometry entrance and its coupling with capillary electrophoresis based on the liquid junction principle. A case study of top-down and bottom-up proteomic analyses of intact cytochrome c and its tryptic digest demonstrates the practical applicability of the developed interface.

• Keywords
• capillary electrophoresis, electrospray ionization, mass spectrometry, microfabrication, proteomics,
• MeSH
• Cytochromes c * analysis   chemistry   MeSH
• Equipment Design MeSH
• Electrophoresis, Capillary * methods   instrumentation   MeSH
• Spectrometry, Mass, Electrospray Ionization * methods   instrumentation   MeSH
• Miniaturization * instrumentation   MeSH
• Nanotechnology * instrumentation   MeSH
• Proteomics methods   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Cytochromes c * MeSH

Capillary electrophoresis coupled online with mass detection is a modern tool for analyzing wide ranges of compounds in complex samples, including urine. Capillary electrophoresis with mass spectrometry allows the separation and identification of various analytes spanning from small ions to high molecular weight protein complexes. Similarly to the much more common liquid chromatography-mass spectrometry techniques, the capillary electrophoresis separation reduces the complexity of the mixture of analytes entering the mass spectrometer resulting in reduced ion suppression and a more straightforward interpretation of the mass spectrometry data. This review summarizes capillary electrophoresis with mass spectrometry studies published between the years 2017 and 2021, aiming at the determination of various compounds excreted in urine. The properties of the urine, including its diagnostical and analytical features and chemical composition, are also discussed including general protocols for the urine sample preparation. The mechanism of the electrophoretic separation and the instrumentation for capillary electrophoresis with mass spectrometry coupling is also included. This review shows the potential of the capillary electrophoresis with mass spectrometry technique for the analyses of different kinds of analytes in a complex biological matrix. The discussed applications are divided into two main groups (capillary electrophoresis with mass spectrometry for the determination of drugs and drugs of abuse in urine and capillary electrophoresis with mass spectrometry for the studies of urinary metabolome).

• Keywords
• capillary electrophoresis, drugs, mass spectrometry, metabolome, urine analysis,
• MeSH
• Electrophoresis, Capillary methods   trends   MeSH
• Mass Spectrometry methods   trends   MeSH
• Pharmaceutical Preparations urine   MeSH
• Humans MeSH
• Metabolomics MeSH
• Urine chemistry   MeSH
• Substance Abuse Detection methods   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Pharmaceutical Preparations MeSH