Measurement of plasma norepinephrine and 3,4-dihydroxyphenylglycol: method development for a translational research study

Table 1 Recoveries following alumina extraction (n = 6)

	M ± SD
	Oxidation^a	Oxidation followed by reduction^a
DHPG	31.0 ± 0.8%	16.3 ± 1.1%
Uric acid	0.15 ± 0.01%	ND
Norepinephrine	49.3 ± 1.2%	35.3 ± 1.0%
DHBA	45.4 ± 1.1%	32.1 ± 0.8%

Comparison of recoveries of processed samples using the oxidation and oxidation–reduction protocols. Standard mixes (n = 6; each containing 0.5 μM DHPG, 0.5 μM NE, and 0.5 μM DHBA) and uric acid (n = 6; each containing 50 μM) were processed and subjected to either the oxidation protocol or the oxidation–reduction protocol. We calculated recoveries of each compound based on the starting amount without alumina extraction. Even though uric acid was poorly adsorbed onto alumina, the concentration of uric acid in plasma is high compared with the catechols and even a small percentage retained obscures the DHPG peak. DHBA dihydroxybenzylamine, DHPG, 3,4-dihydroxyphenylglycol, M mean, ND non-detectable, SD standard deviation
^aRecoveries are expressed as a percentage of the starting amount

ISSN: 1756-0500