Development and Application of Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry Based on DC Bias...

An innovative high-energy collision dissociation (HCD) scheme was developed using a home-built high-precision quadrupole linear ion trap tandem mass spectrometer (Q-LIT). DC-biased enhanced high-energy collision dissociation (DCBE-HCD) achieves accurate collision and efficient fragmentation of gas-phase ions on the existing platform through coordinated regulation and timing programming of the RF electric field and segmented axial DC electric field, thereby overcoming the limitation of HCD relying on a dedicated "collision cell". Based on this, an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for four β-agonists (cimaterol, clenbuterol, terbutaline, and hydroxymethyl clenbuterol) was established. Validation results showed excellent linearity for all analytes within the range of 0.5-50 μg/kg, with correlation coefficients ≥0.999. The limits of detection and quantification were 0.005-0.030 and 0.010-0.100 μg/kg, respectively. At spiking concentrations of 1, 20, and 40 μg/kg, recoveries were 98.26-103.85%. Intraday and interday precisions were 0.57-1.10 and 1.45-2.23%, each in turn. The evaluated method was applied to the Food Analysis Performance Assessment Scheme (FAPAS) "β-Agonists in Pork Muscle Proficiency Test". The detection results of Q-LIT were highly consistent with the joint assignment results of 53 laboratories, with z scores ranging from -0.4 to 0.1, fully meeting the criterion that "|z| ≤ 2 indicates satisfactory performance". These results demonstrated that the UPLC-MS/MS method constructed by DCBE-HCD passed the rigorous assessment of FAPAS, with its accuracy, reproducibility, and applicability all reaching internationally advanced levels, thereby providing a practical example for the application of domestic mass spectrometry in food safety supervision.