Pesticides are chemicals that are used to control pests which may damage crops, so it is essential to minimize the residues of these chemicals or keep within maximum residue limits before brought into the market. The European commission specifies maximum residue limits (MRLs), which defines the maximum level of pesticide residue that is legally permitted in different commodities of food. MRLs are based on field trials data and/or the toxicological and risk assessment studies. In countries like the USA, China and India, pesticide levels are regulated at the national level by Environmental Protection Agency, CFSA and FSSAI respectively. To meet these MRLs in various food commodities, advanced analytical techniques like LC-MS/MS and GC-MS/MS are most useful for confident quantitation at trace levels. Apart from this, a high-resolution mass spectrometer (HRMS) used for screening purpose on the accurate mass measurement.
How You Can Avoid Pesticides
Studies show that people who eat organic foods consume fewer pesticides. Organic food by definition contains no chemicals, fertilizers, and pesticides. It may be a good idea to buy products from small farmers or farmer organization you trust. Organic foods are costlier than commonly available products, but at least food what you get is not contaminated. You can even set up your little garden and enjoy plucking chemical-free fruits and vegetables.
Pesticide Analysis Using LC-MS/MS
LC-MS/MS performs multiple pesticide residues analysis and screening, including those, who are less sensitive or not detected by GC-MS/MS. Tandem mass spectrometers perform accurate identification, and quantification of pesticide residues through specific single reaction monitoring (SRM) transitions for each molecule. This results in very high sensitivity, selectivity, accuracy, and quantitation of several pesticides in various food commodities. However, this approach may sometimes be time-consuming if data handling software is not designed in a user-friendly way. A complex matrix such as high pigment vegetables and fruits makes analysis difficult and may result in a false-positive due to the lack of experience of the operator, and a false-negative due to large matrix interference. High matrix interference can be minimized using a suitable sample preparation technique, before running a sample on LC-MS/MS. QuEChERS technique is widely used for extraction of multi-residue pesticides fruits and vegetables. Modified QuEChERS are also in use looking at a broad spectrum of food products. Many commercial food labs utilizing LC-MS/MS for testing food products for the presence of pesticide residues and analytical methods are validated for precision, accuracy, ruggedness (Guideline- SANTE 11813/2017). To avoid misinterpretation of results in the sample, ion ratio is monitored and compared with the standard, which confirms the identity of compound if ion ratio falls below 30% criteria. Stringent validation criteria ensure lab reports are correct and authentic. Robustness of analytical tools also becomes essential for a laboratory running many samples.
Thermo Fisher Scientific offers the widest range of analytical machines like LC-MS/MS, GC-MS/MS, including advanced high-resolution mass spectrometer (Orbitrap) and hybrid/tribrid patented techniques. All efforts to make food analysis easier, less time consuming, get confident results, and fulfilling our mission is to enable our customers to make the world healthier, cleaner and safer.