title: Determination of octopamine, synephrine and tyramine in Citrus herbs by ionic liquid improved 'green' chromatography.
abstract: Without adding any volatile organic solvents, aqueous solutions of room temperature ionic liquids (RTILs) were used as 'green' mobile phases to determine octopamine, synephrine and tyramine by liquid chromatography. The problems of the adrenergic amines separation, such as band tailing, low retention and low resolution were solved successfully by using RTIL. The effect of 1-ethyl-3-methylimidazolium tertafluoroborate ([EMIM][BF4]) was the best in the six investigated RTILs. The concentration of [EMIM][BF4], mobile phase pH and column temperature, which influenced the chromatographic behaviors of the analytes, were investigated in detail. The change of retention factors caused by pH shift was obviously suppressed by [EMIM][BF4]. The sensitivity, accuracy and repeatability of this method were found to be satisfactory. The contents of adrenergic amines in several Citrus herbs and extracts, such as Fructus aurantii immaturus, were simultaneously determined by this 'green' chromatographic method.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Tang
authors.forename: Liang
authors.initials: L
authors.lastname: Tao
authors.forename: Xubiao
authors.initials: X
authors.lastname: Luo
authors.forename: Li
authors.initials: L
authors.lastname: Ding
authors.forename: Manli
authors.initials: M
authors.lastname: Guo
authors.forename: Lihua
authors.initials: L
authors.lastname: Nie
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000032:analysis / Q000737:chemistry; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid / Q000379:methods*; D002957:Citrus / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000737:chemistry; D009655:Octopamine / Q000032:analysis* / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry; D015203:Reproducibility of Results; D013578:Synephrine / Q000032:analysis* / Q000737:chemistry; D013696:Temperature; D014439:Tyramine / Q000032:analysis* / Q000737:chemistry
chemical_list: C499119:1-ethyl-3-methylimidazolium tetrafluoroborate; D000316:Adrenergic alpha-Agonists; D007093:Imidazoles; D010936:Plant Extracts; D009655:Octopamine; D013578:Synephrine; D014439:Tyramine