A target value for iminoctadine triacetate residues in tap water was set at 6 mu g/l in Japan. We have developed a highly selective and sensitive analytical method for iminoctadine triacetate by solid phase extraction LC/ESI/MS using hydrophilic interaction chromatography. The recovery rates at concentration of 0.06, 0.6, and 6 mu g/l in distilled water, tap water, and raw water were 77.1-96.7%, and CV were 3.7-13.2%. The quantitation limit of the present method was 0.04 mu g/l, and it was able to measure even one-hundredth of the target value of iminoctadine triacetate quantitatively.
