A novel method for the determination of isopropyl-β-D-thiogalactopyranoside (IPTG), a sulfur-containing compound, a pharmaceutical additive in commercial recombinant human growth hormone (rhGH), has been developed using pulsed electrochemical detection (PED), following ion Chromatographic separation. A Dionex-500 ion chromatograph coupled with an electrochemical detector was employed, equipped with a gold working electrode and an Acclaim 300 analytical C18 column, with a mobile phase consisting of sodium acetate (NaOAc) buffer (pH 5.45, 0.01 mol/L) and acetonitrile (ACN)(90/10, v/v). Upon optimization, IPTG was found to have a limit of detection of 1 ng/mL (0.1 μmol) with 25 uL injection volume. This method was successfully applied to the determination of IPTG in rhGH samples with the characteristics of simplicity, high sensitivity and good repeatability.