A Complementary, Quantitative, and Confirmatory Method to UHPLC/ESI Q-Orbitrap Screening Based on UPHLC/ESI-MS/MS for...

Triple quadrupole (MS/MS) and high-resolution mass spectrometry (HRMS), coupled with ultra-high performance (UHP) liquid chromatography (LC) or gas chromatography (GC), are technologies used to analyze pesticide residues in fruits and vegetables. LC-MS/MS has been the gold standard for analysis of pesticides, offering reliable performance and sensitivity, while LC-HRMS is expanding in application to serve as another benchmark. Method development and testing scope expansion are constantly required with new generation mass spectrometers.

This article discusses the development and validation of a quantitative and confirmatory method that can analyze over 400 pesticide residues using a state-of-the-art UHPLC/electrospray ionization (ESI)-MS/MS system.

Homogenized fruit and vegetable samples were fortified with pesticides and were extracted using a modified quick, easy, cheap, effective, rugged, and safe method. Samples were injected onto a UHPLC/ESI-MS/MS system, and data were acquired in multiple reaction monitoring (MRM) mode. The method was validated using a nested experimental design, and was able to quantify and confirm 416 pesticides in fruits and vegetables. It was also complimentary to the UHPLC/ESI Q-Orbitrap quantitative and screening methods previously developed in the authors' laboratory.

The method demonstrated good performance. In all matrixes, 92% of pesticides yielded recoveries between 81-110%, more than 95% of pesticides yielded intermediate precision ≤20%, about 65% of pesticides yielded measurement uncertainties ≤20%, and 96% of pesticides yielded measurement uncertainties ≤50%.

This method shows great potential to be a standalone method or as part of a laboratory workflow for quantitative and confirmatory analysis of pesticide residues in fruits and vegetables.

This method was developed using the same mobile phases, analytical columns, and extraction procedure, as UHPLC/ESI Q-Orbitrap methods. Extracts can be run on either system, streamlining monitoring programs and offering high sample throughput.