Simultaneous Determination of 4 Enniatins in Chinese Herbal Slices by UHPLC-MS/MS

OBJECTIVE To establish a method for the simultaneous determination of 4 enniatins in Chinese herbal slices with ultra-high-performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS). METHODS Samples were extracted with 70% methanol by ultrasound, and the separation of the analytes was carried out on the Agilent Infinity Lab Poroshell 120 SB-C₁₈ column(2.1 mm×100 mm, 2.7 μm) using the mobile phase of 2 mmol·L^-1ammonium acetate and methanol-acetonitrile by gradient elution. The detection was performed in the electrospray ionization(ESI) positive mode and multiple reaction monitoring (MRM) mode, and the matrix-matched calibrations were used to quantify the residue concentrations. RESULTS Satisfactory recoveries of 4 enniatins at low, medium and high spiked levels were ranged from 92.15% to 118.67%. Good linear relationships were obtained and the correlation coefficients(r) were ≥ 0.999, and the limits of detection and quantification ranged from 0.002 to 0.02 μg·kg^-1 and from 0.01 to 0.1 μg·kg^-1 respectively. The results showed that 4 enniatins had different degress of pollution on 17 samples. CONCLUSION The proposed method which is applicative for screening 4 kinds of enniatins is simple, rapid and accurate, and the detection rate is high in Chinese herbal slices.