Determination of a new cerebral vasodilator 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-[2-(N-benzyl-N-methylamino)]-ethyl ester 5-methyl ester hydrochloride (YC-93) in plasma by electron capture gas chromatography.

A highly sensitive method for the quantitative determination of 2,6-dimethyl-4-(3-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylic acid 3-[2-(N-benzyl-N-methylamino)]-ethyl ester 5-methyl ester hydrochloride (YC-93) in plasma is described. After extraction, YC-93 was oxidized to a pyridine analogue with nitrous acid and detected by electron capture gas chromatography. The sensitivity was 2-3 ng/ml, which is sufficient to determine plasma concentrations of YC-93 after oral administration of clinical doses to humans.