Abstract

BENAVIDES VARELA, Silvia  and  FORNAGUERA TRIAS, Jaime. A simple method to collect, extract and measure urinary catecholamines in elderly people. Acta bioquím. clín. latinoam. [online]. 2007, vol.41, n.4, pp.541-552. ISSN 0325-2957.

Catecholamines in plasma and urine have been widely used for clinical diagnosis and research. The present paper proposes simple changes to collect, extract and quantify catecholamines among elderly people, and to obtain more accurate results using HPLC-EC. Refrigeration and acid were tested as preserving methods during urine collection. A pre-treatment with SPE was used to clean samples, and some variables were changed in order to improve recovery previous to chromatography analysis. No significant differences were found in sample catecholamines concentration using different preservation methods, or even in samples without refrigeration or acid during collection. Recovery obtained after changing some variables in SPE was 88.0% in epinephrine, 85.8% in dopamine and 96.9% in norepinephrine. VC was less than 10% between-days and between-run evaluation in all catecholamines, and error was 2.5%. Calibration curves were linear (r²Z0.9882; a<0.001) in matrixes employed. Values obtained in test samples were comparable with previous results reported in elderly people. The method and the changes proposed are useful to measure urinary catecholamines in elderly people. However, it is proposed that they could also be useful for other age groups, and not only for research but also for clinical purposes.

Keywords : Urinary catecholamines; Handling; Solid phase extraction; Epinephrine; Norepinephrine; Dopamine; High performance liquid chromatography.

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