title: Improved method for the routine determination of acetylcholine and choline in brain microdialysate using a horseradish peroxidase column as the immobilized enzyme reactor.
abstract: A modified microbore high-performance liquid chromatography-immobilized enzyme reactor-electrochemical detection system for acetylcholine (ACh) and choline (Ch) was developed. The system used the horseradish peroxidase and a solution mediator ferrocene to convert the analyte into an oxidized ferrocene species which was detected electrochemically by reduction at 0 mV. There was an excellent linear relationship between the concentration of ACh/Ch and the peak height over the range of 1-5000 nmol/l. The limit of detection for ACh was 2 fmol/5 microl (S/N=3:1). Compared with the common method recommended by Bioanalytical System Inc. (BAS), this method exhibits a 200-fold improvement in the detection limit. The ACh and Ch levels in rat brain microdialysate were examined.
authors.affiliation: Center for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun, Beijing 100080, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Dong
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Dihua
authors.initials: D
authors.lastname: Shangguan
authors.forename: Rui
authors.initials: R
authors.lastname: Zhao
authors.forename: Guoquan
authors.initials: G
authors.lastname: Liu
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002794:Choline / Q000378:metabolism*; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006735:Horseradish Peroxidase / Q000378:metabolism*; D017551:Microdialysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D004800:Enzymes, Immobilized; D006735:Horseradish Peroxidase; D002794:Choline; D000109:Acetylcholine