Book Description

A trihydroxyindole procedure for the fluorometric analysis of epinephrine and norepinephrine in urine has been adapted to the Technicon Autoanalyzer. Modifications of the original method of Robinson and Watts include: (1) the use of an alkaline sodium acetate buffer in the column wash, and (2) substitution of 0.1N sodium acetate pH 6.0 in the diluent stream of the autoanalyzer. Twenty-four hr urine specimens from 10 normal subjects were analyzed, giving values of norepinephrine 29.4 micrograms plus or minus 8.1 (standard deviation) 24 hrs, epinephrine 6.6 plus or minus 3.5 and total catecholamines 36 plus or minus 10.7. Repeatibility of 10 aliquots of a single specimen was 32.8 plus or minus 1.7 standard deviations (plus or minus 5%) for norepinephrine, 9.3 plus or minus 0.7 standard deviations (plus or minus 7%) for epinephrine and 42.1 plus or minus 1.6 (plus or minus 4%) for the total catecholamines. Reproducibilities of duplicate aliquots of a single specimen analyzed on 3 different days were 26.1 micrograms plus or minus 2.3 (plus or minus 9%) for norepinephrine and 6.9 plus or minus 0.9 (plus or minus 11%) for epinephrine and 33.6 plus or minus 1.5 (plus or minus 4%) for the total catecholamines. Interference between large and small known samples run sequentially in the analyzer was not seen. Recoveries of columned aliquots was 83 plus or minus 5.4% for norepinephrine, 75 plus or minus 5% for epinephrine and 79 plus or minus 4.6% for the total catecholamines. Automation of the analysis and digital computer computation of the calculations will permit up to 210 analyses per week by a single technician. (Author).