Using Triple-Quad Mass Spectrometry for Pesticide Analysis
Pesticides are used to boost crop yields, which are vital to ensuring food security; however, their use presents a unique challenge to the scientific community. On the one hand, scientists are constantly searching for new pesticides to increase crop yields by addressing a wide variety of changing pest conditions. Unfortunately, pesticides and their metabolites are potentially toxic species that can easily enter food chains and water streams, so regulatory scientists must determine the risk and tolerance for each new pesticide. Once regulations are established, analytical scientists are tasked with finding a suitable method of measurement for each pesticide, and measuring for all relevant pesticides quickly and accurately.
Many jurisdictions have strict legislation and testing requirements for the creation and use of new pesticides and their metabolites, and typically require both identification and quantitation of select pesticides in agricultural products. Mass spectrometry is an exceptional technique for regulatory analysis, because it is compatible with a wide range of chemical types including pesticides and related metabolites. Mass spectrometry also offers unparalleled analysis of complex mixtures.
Triple-quad mass spectrometers are particularly well-suited for pesticide analysis, because they are capable of measuring a large number of compounds with excellent sensitivity and selectivity.1 Another advantage of triple-quad mass spectrometers is that the wide dynamic range allows analysis of concentrated and trace-level compounds.
It is also possible to couple chromatographic techniques, such as gas chromatography (GC), to triple-quad mass spectrometers for handling more complex analytes that require additional separation or would otherwise require extra sample preparation steps before analysis.
How a Triple-Quad Mass Spectrometer Works
The main components of a triple-quad mass spectrometer are two linear quadrupoles that are connected by a collision cell, which is also a type of quadrupole. Gas is introduced into the collision cell to fragment the chemical species selected from the first quadrupole. The third quadrupole then selects the ion of interest and directs it into the detector. In each quadrupole, it is possible to select a subset of ions of interest, giving triple-quadrupole mass spectrometers their excellent selectivity.
The sensitivity of triple-quad mass spectrometers comes from electric fields optimized to collect only one ion at a specified m/z (mass-to-charge ratio). By simultaneously maximizing the number of ions from the selected compound that can travel through the quadrupole and discarding interference ions, trace amounts of compounds can be detected in a variety of complex matrices.
JEOL’s Triple-Quad Mass Spectrometer
JEOL has over 70 years of expertise in crafting advanced scientific instrumentation, and their JMS-TQ4000GC triple-quad mass spectrometer has been designed with pesticide analysis in mind.2,3 Whether samples are agricultural material and require trace-level analysis to check for contamination, or liquids to be checked for persistent environmental pollutants, the superb sensitivity and selectivity of the JMS-TQ4000GC makes it the instrument of choice for a wide range of organic analytes.
Pesticide sampling can mean analyzing a large number of samples every day from a variety of sample types, so the JMS-TQ4000GC triple-quad mass spectrometer has been carefully optimized to minimize run times without sacrificing sensitivity. JEOL has achieved this through the precise synchronization of ion ejection from the collision cell and signal acquisition to maximize signal-to-noise and ion throughput. Even when using fast chromatographic conditions, the JMS-TQ4000GC triple-quad mass spectrometer has the speed, sensitivity, and selectivity to measure targeted analytes in complex samples.
References
- Botisti, H. V., Garbis, S. D., Economou, A., & Tsipi, D. F. (2011). Current Mass Spectrometry Strategies for the Analysis of Pesticides and their Metabolites in Food and Water. Mass Spectrometry Reviews, 30, 907–939.
- JEOL (2021) JEOL, https://www.jeolusa.com/ABOUT-US/The-Company, accessed 27th August 2021
JEOL (2021) JMS-TQ4000GC, https://www.jeolusa.com/PRODUCTS/Mass-Spectrometers/GC-Triple-Quadrupole-Mass-Spectrometer, accessed 27th August 2021