Systematic study of long-term stability of 3,4-dihydroxyphenylglycol in plasma for subsequent determination with liquid chromatography.
The effect of three storage temperature levels (i.e. +4, -20 and -80 degrees C) and time intervals from sampling (3, 6 and 9 months) on the degradation of 3,4-dihydroxyphenylglycol (DHPG) and norepinephrine (NE) was investigated in a systematic study. Extracted human plasma samples and acidified standard solutions were stored for long periods (up to 9 months) without the addition of any stabilizing agent. DHPG and NE values, determined using a ion-pair reversed-phase high-performance liquid chromatography method with electrochemical detection of coulometric type (IP-RP-HPLC-CD), remained constant over time in those plasma samples and standard solutions that had been stored at the lowest storing temperature (i.e. -80 degrees C). The expected degradation was observed at higher temperature levels. Plasma and standard DHPG degradation can, therefore, be prevented by storing samples at a lower temperature than previously suggested with no need to add any stabilizing agent.
Venneri
Maria Grazia
MG
Department of Medicine and Medical Specialties, University of Modena and Reggio Emilia, Modena, Italy. mgv28@libero.it
Del Rio
Graziano
G
D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004563:Electrochemistry; D006801:Humans; D008734:Methoxyhydroxyphenylglycol / Q000031:analogs & derivatives* / Q000097:blood*; D012015:Reference Standards; D012680:Sensitivity and Specificity
D008734:Methoxyhydroxyphenylglycol; C010117:3,4-dihydroxyphenylglycol