title: Analysis of opioid peptides by on-line SPE-CE-ESI-MS.
abstract: In this study, SPE-CE-ESI-MS is explored for the preconcentration and separation of dilute solutions of six opioid peptides. First, a CE-ESI-MS methodology was developed and validated. LODs of around 1 microg/mL were obtained for all the studied peptides. For SPE-CE-ESI-MS experiments, a home-made SPE microcartridge containing a C18 sorbent was constructed near the inlet of the separation capillary. After optimizing the on-line preconcentration methodology, LODs between 10 and 0.1 ng/mL were achieved. Repeatability, reproducibility, durability of the microcartridges and linearity of the SPE-CE-ESI-MS methodology were also investigated and compared to the values obtained by CE-ESI-MS. Finally, human plasma samples fortified with opioid peptides were analyzed by SPE-CE-ESI-MS in order to show the potential of the methodology for the analysis of biological fluids.
authors.affiliation: Department of Analytical Chemistry, University of Barcelona, Barcelona, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Hernández
authors.forename: Fernando
authors.initials: F
authors.lastname: Benavente
authors.forename: Victoria
authors.initials: V
authors.lastname: Sanz-Nebot
authors.forename: José
authors.initials: J
authors.lastname: Barbosa
mesh_terms: D002021:Buffers; D019075:Electrophoresis, Capillary / Q000379:methods*; D004745:Enkephalins / Q000302:isolation & purification; D006801:Humans; D009862:Online Systems; D018847:Opioid Peptides / Q000097:blood* / Q000302:isolation & purification; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D052616:Solid Phase Extraction / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
chemical_list: D002021:Buffers; D004745:Enkephalins; D018847:Opioid Peptides