|Monday, August 25||Postmortem Analysis and Drug Stability|
ANALYSIS OF NOREPINEPHRINE, EPINEPHRINE, L-DIHYDROXYPHENYLALANINE AND DOPAMINE IN SAMPLES OF POSTMORTEM URINE BY HPLC AND ELECTROCHEMICAL DETECTION|
Procaccianti P., Argo A.
This paper presents a sensitive and selective reversed-phase high-performance liquid chromatographic procedure applied to urinary assay of bioamines in postmortem samples. A method based on coulometric detection in the reductive mode, was adapted for simultaneous determination of low concentrations (pg/mL) of norepinephrine (Ne), Epinephrine (E), L-dihydroxyphenylalanine (L-DOPA) and dopamine (DA) in human urinary samples using 3,4-dihydroxy-benzylamine as internal standard. By using a one-step extraction, the analytes were extracted from 200 l of sample with perchloric acid, after alumina pre-activated adsorption at alkaline pH. The chromatographic conditions and the potential settings were tested in order to obtain suitable working conditions: the potentials for optimal detector response with minimal interferences were +250 mV for the first oxidative electrode and -200 mV for the second reductive electrode, operating in the redox mode. The chromatographic separation was completed within 20 min. Under these conditions suitable recovery and detection of levels as low as 100 pg/mL of NE, 200 pg/mL of E, 150 pg/mL of L- DOPA, 250 pg/mL of DA were obtained. The major interest of our method is its applicability to small samples containing different matrix interferences and low quantities of analytes, such as postmortem urinary samples. The possibility of its routine application in toxicological screening of urinary autopsy specimens is shown.
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