Hsin-Chang Chen

Pesticides are chemicals or biological agents to intentionally control pests including weeds, and they are widely used in agriculture. The type of approved pesticides and their regulated maximal residue levels (MRLs) in consumer products are different from country to country. For example, official monitoring for residue pesticides in food in Taiwan mainly focused on 375 approved pesticides with MRLs and 59 banned pesticides by three standard methods. In the era of global village, however, Taiwan also seeks food from overseas, e.g. strawberries from Korea, and the difference of approved pesticides between Taiwan and Korea is obvious since 460 pesticides with MRLs in food are approved by Korea. Korean fruits may contain pesticides non-approved in Taiwan.

To realize the occurrence of pesticides in imported fruits, a liquid chromatography-high-resolution mass spectrometry (LC-HRMS) with a TASQ software was applied for screening and data processing. A Bruker TargetScreener HR 3.0 accurate mass database was then utilized to confirm the multi-residue pesticides based on the criteria of retention time, mass accuracy and diagnostic ions. Preliminary results indicated 11 authorized pesticides were qualified with the similar results obtained from the TFDA standard method, and another 15 approved pesticides were also qualified in the Korean strawberries. Nevertheless, six non-authorized pesticides were confirmed in this imported fruit. Our Study demonstrated the capability and feasibility of LC-HRMS with database to screen non-authorized pesticides in food.