title: Spurious serotonin dimer formation using electrokinetic injection in capillary electrophoresis from small volume biological samples.
abstract: One normally assumes that the analytical measurement process does not introduce spurious compounds. Capillary electrophoresis is a separation method frequently used for small-volume biological measurements. We demonstrate the potential for creating new peaks in a capillary electropherogram when using electrokinetic injections and illustrate the potential deleterious effects with biological samples involving serotonin and nitric oxide measurements. Specifically, when measuring the serotonin content from individual neurons using electrokinetic injections from 360 nL stainless steel vials, we detect a new peak that we identify as a serotonin dimer. We do not observe this peak when using hydrodynamic injections.
authors.affiliation: Department of Chemistry and Beckman Institute, 600 S. Mathews Ave 63-5, University of Illinois, Urbana, IL 61801, USA. jsweedle@uiuc.edu
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Stuart
authors.forename: Nathan G
authors.initials: NG
authors.lastname: Hatcher
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Rhanor
authors.initials: R
authors.lastname: Gillette
authors.forename: Jonathan V
authors.initials: JV
authors.lastname: Sweedler
mesh_terms: D000818:Animals; D019281:Dimerization; D019075:Electrophoresis, Capillary / Q000379:methods*; D005189:False Positive Reactions; D007267:Injections; D009474:Neurons / Q000737:chemistry*; D009569:Nitric Oxide / Q000032:analysis; D012701:Serotonin / Q000032:analysis*
chemical_list: D009569:Nitric Oxide; D012701:Serotonin