Abstract: Objective: A method for the simultaneous determination of the contents of 3-monochloropropane-1,2-diol ester (3-MCPDE), 2-monochloropropane-1,3-diol ester (2-MCPDE), 1,3-dichloropropane-2-ol ester (1,3-DCPE) and 2,3-dichloropropane-1-ol ester (2,3-DCPE) in infant formula was established by gas chromatography-mass spectrometry (GC-MS). A total of 50 infant fomlula samples sold in Shanghai were researched. Methods: In this study, fat was extracted from samples, followed by alkali hydrolysis-EXtrelut NT diatomite column purification-derivatived with heptafluoro butyrylimidazole-quantified by internal standards. Results: The method showed good linear relationship in the range of 20～600 ng/mL (r2≥0.998 9). The detection limit and quantification limit were 0.005 mg/kg and 0.015 mg/kg, respectively. The recoveries of the four chloropropanols esters spiked at 0.03, 0.075 and 0.15 mg/kg were between 82.2%～113.9%, and the relative standard deviations were less than 8.3%. Of the 50 infant formula samples, the detection rates of 3-MCPDE and 2-MCPDE were 100.0% and 42.0%, with the contamination levels in the range of 0.037～0.208 mg/kg and ND～0.060 mg/kg, respectively. 1,3-DCPE and 2,3-DCPE were not detected in the 50 samples. The average exposures of chloropropanols esters in infant formula were 3.86, 2.00 and 1.07 μg/kg for 0-6 months old, 6-12 months old and 12-36 months old, respectively. Conclusion: The method was easily operated with good accuracy and good reliability, and suitable for the determination of chloropropanols esters in infant formula. The health risk of chloropropanols esters caused by the intake of infant formula for infants, needs to be concerned.

Key words: chloropropanols fatty acid esters, gas chromatography-mass spectrometry (GC-MS), infant formula