Resolution of chromatographic peaks through voltammetric detection for l-dopa, 6-hydroxydopa and tyrosine

Abstract

Voltammetric detection was used to resolve overlapped chromatographic peaks for l-dopa and 6-hydroxydopa. The coulastatic detector provided complete resolution (column resolution = 0.6) even though the oxidation potentials for these two species differed by less than 200 mV. The instrument can be used to resolve and accurately quantify both overlapped components from a single chromatographic injection. Further, the detector can be used to resolve three components, tyrosine, l-dopa, and 6-hydroxydopa, although the chromatographic separation provided complete resolution of tyrosine from the other components. Detection limits were 1.7 ng for tyrosine and 11 ng for l-dopa.