Determination of 2 Phthalic Acid Esters in Fermented Grains by GC–MS/MS Coupled with Modified QuEChERS

Phthalate esters (PAEs) are harmful to human health and have been identified in Baijiu and Baijiu brewing process. Fermented grains are important intermediate products in Baijiu brewing process and are easily polluted by PAEs. Accurate analysis and monitoring of PAEs content in fermented grains would be of great significance for the control of Baijiu plasticizer pollution. In this study, the method of gas chromatography-triple quadrupole mass spectrometry (GC–MS/MS) coupled with modified QuEChERS was established to analyze the concentration of PAEs, including dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) in fermented grains. In this method, determination of coefficients (R²) was greater than 0.99 in the range of 20–1000 μg/L. The average recoveries (spiked at 100, 500, and 750 μg/L) were considered satisfactory, with values ranging from 84.06 to 113.72% and relative standard deviations from 0.96 to 4.24%. The LOD and LOQ were 0.03 to 0.25 μg/L and 0.10 to 1.0 μg/L, respectively. Moreover, the concentrations of PAEs measured by this method were ranged from 0.190 to 0.635 mg/kg in fermented grains, and the results showed that DBP and DEHP in the fermented grains were higher than those in brewing raw materials and Baijiu. The foregoing findings suggested that this method meets the requirements for the analysis of PAEs in fermented grains.