Determination of the potential illegal addition of β-blockers to function foods by QuEChERS sample preparation and...

A novel method was established for the determination of 11 β-blockers in sedative functional foods using QuEchERS sample preparation coupled with UPLC-MS/MS. The analytes were extracted twice with acetic acid-acetonitrile-methanol (0.1:3:7, v/v/v), and the extracts were purified with mixed QuEchERS adsorbents. Separation was performed on a C18 column, and detection using electrospray ionisation in positive-ion mode. The linear range for the 11 analytes was from 1 to 500 μg l(-1), and the correlation coefficients were above 0.9990. The limits of detection and quantification were 0.02-0.16 and 0.07-0.54 μg kg(-1), respectively. The average recovery for 11 analytes at the three spiking levels varied from 71.8% to 121.9%, and the relative standard deviation was 2.4-12.6%. The method was applied to the analysis of β-blockers in 22 real samples, but none of the analytes was detected. The proposed method is sensitive, efficient, reliable and applicable to real samples.