Rapid Screening of beta-Agonists in Animal Hair by Thermal Desorption Electrospray Ionization Mass Spectrometry

Background Even though the use of beta-agonists in livestock has been banned in many countries, beta-agonists abuse is still out of control owing to time-consuming and complicated determination techniques. Objective This study applied ambient thermal desorption electrospray ionization mass spectrometry (TD-ESI/MS) as a new strategy for rapidly screening seven beta-agonists. As it does not require pretreatment, this method allows on-site and real-time detection. Method Samples were collected directly using a simple metal probe. Analytes on the probe were desorbed and ionized by TD-ESI, after which analyte ions were detected using a triple quadrupole mass analyser. Results The results showed that a thermal desorption temperature of 320 degrees C and nebulizer pressure of 3 psi demonstrated the highest sensitivity. Excellent linear relationships were obtained in concentrations ranging from 10 to 400 mu g/kg. The limit of detection of the method was 1-10 mu g/kg with RSDs of 7.2-14.6%. A positive sample was verified using HPLC coupled with triple quadrupole tandem mass spectrometry, consistent with the results from TD-ESI/MS. Conclusion This method was the first to apply TD-ESI/MS to rapid analyse beta-agonists in livestock hair and was proven to be accurate, fast, and environmentally friendly. Because qualitative screening for each analysis was completed within approximately 1 min, the method could contribute to preventing non-compliance in the flow of animal-derived food to the market.