Determination of indicine N-oxide and indicine in plasma and urine by electron-capture gas-liquid chromatography.

A sensitive and specific method is described for the quantitative analysis of indicine N-oxide and indicine in plasma and urine. Indicine N-oxide is reduced to the tertiary amine with zinc--acetic acid (plasma) or zinc--ammonium chloride (urine). The indicine is derivatized with pentafluoropropionic anhydride to provide electron-capture detection. Assay of rabbit and human plasma and urine samples can detect 100 ng/ml (plasma) and 200 ng/ml (urine), and the method was applied to the analysis of indicine N-oxide and indicine in rabbits and one patient following administration of indicine N-oxide.