Screening Analysis Using Accurate Mass Data and MetID Solution

Our living environment is overflowing with a wide variety of chemicals, and the effects of these chemicals on health are becoming a worldwide concern. Problems such as melamine being added to pet food materials either intentionally or through human error, and pesticides finding their way into frozen dumplings are revelations that are still fresh in our memories. Even considering pesticides alone, more than a thousand different kinds of compounds are in current use, and great importance has been attached to development of a screening technique that can screen for all of these in a single analysis. If a standard solution of these substances happened to be available, identification and quantitation could be conducted with a triple quadrupole mass spectrometer using MRM (Multiple Reaction Monitoring) in an approach known as Targeted Screening. Absent such a standard solution, this approach is inapplicable. In this situation, the only prior information is the compound information, and the index for compound identification becomes the accurate mass of each compound. Screening for compounds without the use of standard solutions is referred to as Non-targeted Screening. Instrument systems that are typically used for non-targeted screening include time-of-flight, orbital trap and FT-ICR high resolution mass spectrometers (HRMS). This report introduces a non-targeted screening technique using the LCMS-IT-TOF quadrupole ion trap time-of-flight spectrometer with the MetID Solution metabolite identification support software.