title: Capillary electrophoresis mass spectrometry with sheathless electrospray ionization for high sensitivity analysis of underivatized amino acids.
abstract: A high durability sheathless electrospray ionization interface of CE-MS is applied for the sensitive analysis of underivatized amino acids. The sheathless interface was realized using an ionophore membrane-packed electro-conduction channel. The interface functioned well with a volatile alkaline background electrolyte (BGE) and uncoated fused-silica capillaries for CE-MS analysis of underivatized amino acids. High electroosmotic flow with alkaline BGE facilitated high separation efficiency (>100,000 theoretical plates) and short analysis time (<15 min). Both the short-term stability and long-term durability are particularly suited for routine applications. Using electrokinetic injection and the multiple reaction monitoring (MRM) mode with a triple-quadrupole analyzer, high sensitivity was achieved, which yielded detection limits of 0.05-0.81 μM. For the quantitation of underivatized amino acids, quantification precisions (RSDs) for intra- and inter-day analyses were less than 3%. Recoveries from serum were 96.3-101.8% for isotope dilution mass spectrometry (IDMS). When compared with HPLC-IDMS for human serum samples, highly agreeable (96.9-102.0%) results were obtained with the proposed CE-IDMS method.
authors: Center for Bioanalysis, Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, Daejeon, South Korea.
authors: Ji-Seon
authors: JS
authors: Jeong
authors: Sook-Kyung
authors: SK
authors: Kim
authors: Sang-Ryoul
authors: SR
authors: Park
mesh_terms: D000596:Amino Acids / Q000032:analysis* / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D019075:Electrophoresis, Capillary / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D000596:Amino Acids