Sensitive high performance liquid chromatographic analysis of ethmozin in plasma.

A sensitive high performance liquid chromatographic procedure for the quantitative determination of ethmozin is described. Following a one-step extraction of the drug and the internal standard, protriptyline, by diethylether at pH 9.0, the organic solvent is evaporated and the residue is reconstituted in the mobile phase and injected into the chromatograph. The separation is obtained using a CN-bonded column with a methanol-propanol-2-perchloric acid 1.16 M mobile phase. Ethmozin is detected at 268 nm. Under these conditions, the lower limit of detection is 11 nM, and the lower limit of quantification is 22 nM (10 ng/ml) for ethmozin. The procedure is linear between 0 and 8,620 nM.