Sabbioni Cesare, Saracino Maria Addolorata, Mandrioli Roberto, Pinzauti Sergio, Furlanetto Sandra, Gerra Gilberto, Raggi Maria Augusta
Department of Pharmaceutical Sciences, Faculty of Pharmacy, Alma Mater Studiorum--University of Bologna, Via Belmeloro 6, 40126 Bologna, Italy.
J Chromatogr A. 2004 Apr 2;1032(1-2):65-71. doi: 10.1016/j.chroma.2004.01.008.
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.
