title: Simultaneous liquid chromatographic analysis of catecholamines and 4-hydroxy-3-methoxyphenylethylene glycol in human plasma. Comparison of amperometric and coulometric detection.
abstract: The comparison of two HPLC methods, one with electrochemical detection and the other with coulometric detection, for the simultaneous analysis of catecholamines and 4-hydroxy-3-methoxyphenylethylene glycol (MHPG) in human plasma is presented. The careful pre-treatment of plasma samples is based on an innovative two-step procedure by means of solid-phase extraction (SPE) which uses one single hydrophilic-lipophilic balance cartridge. The extraction yield values found were higher than 85% for epinephrine, norepinephrine and MHPG, and higher than 70% for dopamine. The assays carried out on real plasma samples with the coulometric system gave good results in terms of sensitivity (limits of quantitation: 0.10-0.15 ng ml(-1) for catecholamines, 0.6 ng ml(-1) for MHPG) and selectivity, while interference was sometimes found when using the amperometric system. Precision was also satisfactory, with relative standard deviation values for intermediate precision always lower than 6%. The HPLC method with coulometric detection coupled to a novel SPE procedure is thus suitable for the simultaneous determination of catecholamines and MHPG in plasma of volunteers subjected to experimental stress.
authors.affiliation: Department of Pharmaceutical Sciences, Faculty of Pharmacy, Alma Mater Studiorum--University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy.
authors.forename: Cesare
authors.initials: C
authors.lastname: Sabbioni
authors.forename: Maria Addolorata
authors.initials: MA
authors.lastname: Saracino
authors.forename: Roberto
authors.initials: R
authors.lastname: Mandrioli
authors.forename: Sergio
authors.initials: S
authors.lastname: Pinzauti
authors.forename: Sandra
authors.initials: S
authors.lastname: Furlanetto
authors.forename: Gilberto
authors.initials: G
authors.lastname: Gerra
authors.forename: Maria Augusta
authors.initials: MA
authors.lastname: Raggi
mesh_terms: D016022:Case-Control Studies; D002395:Catecholamines / Q000097:blood*; D004563:Electrochemistry / Q000379:methods*; D006801:Humans; D008734:Methoxyhydroxyphenylglycol / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019966:Substance-Related Disorders / Q000097:blood
chemical_list: D002395:Catecholamines; D008734:Methoxyhydroxyphenylglycol