Abstract: A robust analytical method was established for the determination of eight bisphenol compounds in infant formula by using quick, easy, cheap, effective, rugged, safe-solid phase extraction (QuEChERS-SPE) for sample preparation and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for compound identification and quantitation. Bisphenol compounds from samples were extracted with acetonitrile, and the extract was subjected to sequential QuEChERS-SPE treatment to remove background interferences. The matrix-matched standard calibration method was used for quantitation. The results showed great reduction of the matrix effect with corrected matrix factor ranging 0.80–1.20 for the 8 bisphenols. within the linear range, the correlation coefficients (R2) of the calibration curves for the compounds were greater than 0.999. The method recovery was 50.2%?116% (n = 6) with relative standard deviations of 0.5%?14%. The limits of detection (LODs) and the limits of quantification (LOQs) were 0.017?0.78 and 0.055?2.6 μg/kg for milk powder, and 0.001 1?0.055 and 0.003 5?0.18 μg/L for liquid milk, respectively. The method was applied to different brands of infant formulas in Chinese and Canadian markets. Based on measured concentrations and infant daily consumption of milk, the potential dietary intakes of BPA, BPF and BPS (calculated from the highest concentrations) were estimated to be 0.065, 0.050, and 0.005 9 μg/(kg·d), respectively. The estimated intakes did not exceed the tolerable daily intake (4 μg/(kg·d)) set by the European Food Safety Association.

Key words: bisphenol compounds, quick, easy, cheap, effective, rugged and safe (QuEChERS), solid phase extraction (SPE), UPLC-MS/MS, matrix factor, infant formula and liquid milk