Simultaneous HPLC Determination of Preservatives in Milk Products

A method of HPLC for the simultaneous determination of 7 preservatives, including dimethyl fumarate, natamycin, methylparaben, ethylparaben, propylparaben, isobutylparaben and butylparabe, in milk products was proposed. The sample was extracted with methanol, and the extract was separated on Symmetry C18 chromatographic column (4.6 mm×25 mm, 5 μm) with a mixture of methanol-0.02 mol·L-1 ammonium acetate (60+40) as mobile phase, and the photodiode array detector was used in the determination. Baseline separation of 7 preservatives was obtained within 20 min. The proposed method was applied to the analysis of samples of milk products, giving values of recovery and RSD′s (n=6) in the ranges of 87.5%-104% and 2.5%-8.8% respectively.