Simultaneous Quantitative Determination and Screening of Pesticides using Orbitrap MS Technology

Pesticide residue analysis is a challenging task because of the high number (>800) of substances that needs to be analyzed. Of these, some 100 are often present while the others are found only at (very) low frequencies. This calls for two analytical approaches: a quantitative method with all associated analytical quality control (AQC), and a screening method to cover as many as possible additional pesticides with minimal efforts in terms of data handling and AQC-burden, respectively.

With the recent improvements in high resolution MS it is possible to combine the two approaches in one measurement. This presentation will focus on application of full scan analysis using chromatography coupled to Q Orbitrap mass spectrometry. The different non-target acquisition options of the instrument will be explained.

For LC, the combination of full scan and vDIA (variable Data Independent Acquisition) was found to provide optimal sensitivity selectivity and identification. Both quantitative and qualitative performance were evaluated according to the EU guidelines for validation and AQC (SANCO/12571/2013) and it is demonstrated that the new technology is fit-for-purpose and can be applied as a more efficient and effective alternative to LC-triple quadrupole MS/MS.

For pesticides not amenable to LC-MS, it would be highly desirable to follow a similar approach in GC analysis. However, unlike LC, there has been a gap in the capabilities of full scan MS for GC in terms of mass resolving power, sensitivity and/or quantitative performance. The coupling of Orbitrap MS to GC may fill this gap. The first results of the use of a GC-Orbitrap system will be presented and are promising. It is foreseen that within the near future, full scan high resolution MS could replace triple quadrupole MS/MS as main stream detector in chromatographic residue analysis.

Watch presentation here.