RP-HPLC Determination of α-［(Dimethylamino) Methylene］-β-keto-2-Thiophenepropanonitrile

A method for the determination of α-［(dimethylamino) methylene］-β-keto-2-thiophenepropanonitrile (abbreviated as IDP-3) by RP-HPLC was proposed. IDP-3 and its by-products were separated on Phenomex C18 column (4.6 mm×250 mm, 5 μm), using a mixture of methanol and water mixed in different ratios as mobile phase in the gradient elution. External standard calibration was adopted in the determination at the wavelength of 330 nm. It was found that under the optimum condition, IDP-3 was well separated from the co-existing substances. Linear relationship between values of peak area and concentration of IDP-3 was obtained in the range of 10.0-100 mg·L-1, with values of detection limit (3S/N) and lower limit of determination (10S/N) of 0.01 mg·L-1 and 0.035 mg·L-1 respectively. Test for precision was made, and values of intraday RSD′s (n=6) found were in the range of 0.43%-0.64%.