title: [Solvent extraction and high performance liquid chromatography with electrochemical detection for determination of plasma catecholamines].
abstract: This paper describes a technique for selectively extracting plasma catecholamines prior to quantification by HPLC-EC. The extraction system was a two-stage process. The first stage involve the complex formation between diphenylbrorate and catechol (diol) groups in alkaline medium. The second stage was a liquid-liquid extraction. The complex combined with tetraoctylammonium bromide to form an ion-pair formation into organic solvent. The catecholamines in turn was extracted with acid. This technique provided a very specific extraction procedure which resulted in chromatograms with few interfering compounds and gave absolute recoveries (100-103%) of norepinephrine, epinephrine and dopamine. Meanwhile, the plasma catecholamines were concentrated and the detective sensitivity was increased. A good linear relationship was found between the concentrations and ratio of peak heights of the catecholamines from 0.125-2 ng. The correlation coefficients ranged from 0.998-0.999. The coefficients of variation of the intra- and inter-assay were within 3 and 6% respectively. The results show that the procedure is very simple and fast. The method is valuable not only for clinical diagnosis but also for laboratory research.
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: W K
authors.initials: WK
authors.lastname: Zhao
mesh_terms: D002395:Catecholamines / Q000097:blood*; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000031:analogs & derivatives / Q000097:blood; D004563:Electrochemistry; D004837:Epinephrine / Q000097:blood; D006801:Humans; D009638:Norepinephrine / Q000097:blood
chemical_list: D002395:Catecholamines; C022133:3,4-dihydroxybenzylamine; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine