Determination of L-erythro-tetrahydrobiopterin in biological tissues by high pressure liquid chromatography and electrochemical detection.

L-erythro-Tetrahydrobiopterin (H4-biopterin) was determined in rat tissue (liver, striatum, brain stem) by reversed phase high pressure liquid chromatography and subsequent electrochemical detection. Due to the low oxidation potential (+ 250 mV) necessary for the analysis of H4 biopterin, the electrochemical detector is a highly selective system for this compound. For analysis of H4 biopterin in biological tissues, only one extraction step with 0.2M perchloric acid and 10mM ascorbic acid is necessary prior to analysis. The H4 biopterin content of rat tissue determined with this method corresponds well with the values reported elsewhere.