title: Preparation and evaluation of an immunoaffinity sorbent with Fab' antibody fragments for the analysis of opioid peptides by on-line immunoaffinity solid-phase extraction capillary electrophoresis-mass spectrometry.
abstract: An immunoaffinity (IA) sorbent with antibody fragments was prepared for the analysis of opioid peptides by on-line immunoaffinity solid-phase extraction capillary electrophoresis-mass spectrometry (IA-SPE-CE-MS). The antibody fragmentation was evaluated by MALDI-TOF-MS. Fab' fragments obtained from a polyclonal IgG antibody against Endomorphins 1 and 2 (End1 and End2) were covalently attached to succinimidyl silica particles to prepare the IA sorbent. An IA-SPE-CE-MS methodology was established analyzing standard solutions of End1 and End2 and acceptable repeatability, linearity ranges and LODs (0.5 and 5 ng mL(-1), respectively) were obtained. The LOD of End1 was slightly better than that previously obtained using an IA sorbent with intact antibodies (1 ng mL(-1)). In human plasma samples, End1 and End2 could be detected at 1 and 50 ng mL(-1), respectively, which meant an improvement of 100 and 2-fold with regard to the LODs using an IA sorbent with intact antibodies (100 ng mL(-1)).
authors.affiliation: Department of Analytical Chemistry, University of Barcelona, Barcelona, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Medina-Casanellas
authors.forename: Fernando
authors.initials: F
authors.lastname: Benavente
authors.forename: José
authors.initials: J
authors.lastname: Barbosa
authors.forename: Victoria
authors.initials: V
authors.lastname: Sanz-Nebot
mesh_terms: D019075:Electrophoresis, Capillary / Q000379:methods*; D007140:Immunoglobulin Fab Fragments / Q000276:immunology* / Q000302:isolation & purification; D007163:Immunosorbent Techniques; D057230:Limit of Detection; D013058:Mass Spectrometry / Q000379:methods*; D009842:Oligopeptides / Q000032:analysis / Q000097:blood / Q000276:immunology; D009862:Online Systems; D018847:Opioid Peptides / Q000032:analysis* / Q000097:blood; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D007140:Immunoglobulin Fab Fragments; D009842:Oligopeptides; D018847:Opioid Peptides; C105293:endomorphin 1; C105294:endomorphin 2
keywords: Antibody fragment; Capillary electrophoresis; Immunoaffinity; Mass spectrometry; Neuropeptide; On-line preconcentration