14 Apr 2010 --- Thermo Fisher Scientific Inc., the world leader in serving science, has introduced an application note demonstrating how the Thermo Scientific Exactive LC/MS system, powered by Orbitrap technology, can be used to perform non-targeted and accurate screening, detection and separation of 510 pesticides at low ppb levels in just 12 minutes.

Increasing food safety concerns and the growing agricultural trade has resulted in stringent pesticide regulations being enforced globally. This is especially true in the EU and Japan, where regulations for pesticides are now among the strictest, with maximum residue levels (MRLs) allowed in food products set at 0.1 mg/kg (10 ppb) for most compounds. To comply with stricter food safety standards such as these, the U.S. Environmental Protection Agency (EPA) recommended the revocation or modification of thousands of uses of pesticides following a 2007 review of 9,721 pesticide tolerances. Overall, tighter regulations require that companies worldwide require sensitive, fast and cost-effective instrumentation for high-throughput screening of multi-class pesticides in food.

Leveraging the proven mass analyzer technology of the Thermo Scientific Orbitrap platform, the Exactive mass spectrometer delivers ultra high resolution and accurate mass data to enable the rigorous and fast characterization of analytes in complex matrices with the advantage of stable and reproducible accurate mass. The new application note details how the Exactive with the Thermo Scientific Accela U-HPLC system can be used to perform non-targeted and accurate screening, detection and separation of 510 pesticides at low ppb levels in just 12 minutes, increasing sample throughput.

To evaluate the applicability of this technique to complex food samples, scientists examined pesticides extracted from a spiked spinach matrix that represented a broad spectrum of chemical classes. Experimental results showed that the Accela U-HPLC system improved chromatographic resolution, speed and sensitivity. The scientists achieved even faster, higher-throughput analysis of challenging samples when they coupled Accela with an Exactive mass spectrometer. The high-resolution provided by the Exactive LC/MS platform (up to 100,000 FWHM) facilitates the accurate mass confirmation of all compounds, including isobaric compounds in complex samples.

"Exactive continues to push the limits of performance for a benchtop mass spectrometer," noted James Chang, food safety specialist with Thermo Fisher.
"For demanding, high-throughput applications, Exactive is an ideal tool for rapid screening, quantitation and accurate mass confirmation."

The application note also demonstrates that the Exactive with Accela offers excellent linearity in detector response over the range of 1-250 ppb, with correlation coefficients for the majority of pesticides greater than 0.99.
Limits of quantification (LOQs) ranged from 1 - 50 ppb, and for 499 pesticides LOQs were at or below the MRL of 10 ppb imposed by EU and Japanese regulations. The Exactive and Accela U-HPLC system is also robust, easy to operate and cost-efficient, making it ideal for routine screening and monitoring of targeted and non-targeted pesticides in regulatory laboratories worldwide.

The comprehensive Thermo Scientific food safety offering includes a wide range of sample collection, sample preparation, instrumentation and data management products focused on the needs of food safety. In addition, a broad portfolio of chemicals, consumables, equipment and supply chain services are available through Fisher Scientific. From research to testing and monitoring, Thermo Fisher provides methods-based consulting and applications support in addition to a comprehensive line of products. Thermo Scientific solutions enable fast and accurate testing of potentially harmful contaminants in food, including chemical residues, fungicides, natural toxins, pathogens, pesticides, trace elements and veterinary drugs.