Evaluation of Four Methods for Catecholamine Analysis in Plasma Obtained From Subjects During Incremental Cycle Ergometry

Abstract

Plasma was collected from a subject during incremental cycle ergometry in order to determine the anaerobic threshold. Norepinephrine and epinephrine were extracted using alumina, strong-cation exchange/alumina, or weak-cation exchange, and then separated using reversed-phase ion-pair chromatography. Amperometric detection was used following chromatography for all three types of extractions (Methods A, B and C), while coulometric detection was only used following chromatography and alumina extraction (Method D). The upper limit of linearity was the lowest for Method C. The extraction for Method B took about twice the amount of time as the other extractions. The standard curve for Methods A, B and D was linear to 5000 ng/L. The lowest limit of quantification and relative standard deviation was obtained using Method D. In summary, Method D was the best method for this purpose.