Optimizing a 190+ Pesticides Multi‐Residue Screening Workflow for the Preparation and Analysis of Produce by LC‐MS/MS

Pesticides are ubiquitously used to help increase crop yields; however, they can pose risks for public health and pollinators (honeybees). Faster multi-residue screening workflows, which combine easier sample preparation techniques that yield higher recoveries with lower instrument detection limits in fruits and vegetables, are often sought. Accomplishing these goals increases sample throughput, and reduces costs for laboratories and their clients. To demonstrate the feasibility of developing improved methods, organic celery and other representative matrices were spiked with pesticides down to 10 ppb. Samples were extracted using Restek QuEChERS Slim Pouch salts, and cleaned up with complementary dSPE. Each sample was diluted 10x with water prior to analysis. Separations were performed with a Restek Raptor ARC-18 column (100 mm x 2.1 mm, 2.7 μm) on a Shimadzu Nexera UHPLC. A Shimadzu LCMS-8060 was used for detection. Recovery and precision results from organic celery, spinach, avocado, orange, brown rice flour and honey will be shown. Poster Category: Chemical Contaminants and Residues Poster Number: CHCR-01 Coauthors Landon A Wiest, RESTEK Corporation Dan Li, RESTEK Corporation Alexacndria M Pavkovich, RESTEK Corporation Sue Steinike, RESTEK Corporation Justin Steimling, RESTEK Corporation Developing a robust LC-MS/MS method for the determination of anionic polar pesticides in a range of foodstuffs without derivatization Emily Britton, Joe Romano, Dimple Shah, Benjamin Wuyts, and Euan Ross Corresponding Author Emily Britton, emily_britton@waters.com Waters Abstract Glyphosate continues to cause controversy and so analysis is of considerable interest to governments, the food industry and contract testing laboratories. Many wish to move away from methodology that employs derivatization to save time and expand the scope to cover other polar and ionic pesticides. Chromatographic retention and separation were optimized using a novel hydrophilic interaction liquid chromatography (HILIC) column, applying an acidified mobile phase gradient, with and without ammonium formate. The performance of a buffered and un-buffered version of the method was compared. Removal of the ammonium formate from the mobile phase resulted in improved sensitivity without compromising chromatographic performance. The aim was to achieve chromatographic retention and baseline separation of isobaric compounds whilst providing maximum sensitivity of all target analytes. Foods of plant origin were prepared using a modified version of the Quick Polar Pesticides (QuPPe) extraction procedure and spiked with a panel of representative anionic polar pesticides for analysis. All analytes were sufficiently detected at concentrations <0.01 mg/kg in matrix-matched standards using the new acidified method. All isobaric pairs (AMPA/fosetyl al and fosetyl al/phosphonic acid) were well separated. The performance was assessed using the relevant criteria defined in the SANTE guidance document (SANTE/11813/2017). Linearity was assessed through matrix-matched calibration over a suitable concentration range (0.001-0.1 mg/kg). Ion ratios and retention times agreed well with reference values and all were within the required tolerances (±30 % and ±0.1 minutes, respectively).Glyphosate continues to cause controversy and so analysis is of considerable interest to governments, the food industry and contract testing laboratories. Many wish to move away from methodology that employs derivatization to save time and expand the scope to cover other polar and ionic pesticides. Chromatographic retention and separation were optimized using a novel hydrophilic interaction liquid chromatography (HILIC) column, applying an acidified mobile phase gradient, with and without ammonium formate. The performance of a buffered and un-buffered version of the method was compared. Removal of the ammonium formate from the mobile phase resulted in improved sensitivity without compromising chromatographic performance. The aim was to achieve chromatographic retention and baseline separation of isobaric compounds whilst providing maximum sensitivity of all target analytes. Foods of plant origin were prepared using a modified version of the Quick Polar Pesticides (QuPPe) extraction procedure and spiked with a panel of representative anionic polar pesticides for analysis. All analytes were sufficiently detected at concentrations <0.01 mg/kg in matrix-matched standards using the new acidified method. All isobaric pairs (AMPA/fosetyl al and fosetyl al/phosphonic acid) were well separated. The performance was assessed using the relevant criteria defined in the SANTE guidance document (SANTE/11813/2017). Linearity was assessed through matrix-matched calibration over a suitable concentration range (0.001-0.1 mg/kg). Ion ratios and retention times agreed well with reference values and all were within the required tolerances (±30 % and ±0.1 minutes, respectively). Poster Category: Chemical Contaminants and Residues Poster Number: CHCR-02 Coauthors Joe Romano, Waters Dimple Shah, waters Benjamin Wuyts, Waters Euan Ross, Waters Detection of Pesticides and Herbicides in Craft Beer Using DART-MS Frederick Liu, Brittany Laramee, Taylor Feraco, Paul Liang, and Brian Musselman Corresponding Author Frederick Liu, li@ionsense.com Ionsense, Inc. Abstract The plants that produce the main agricultural ingredients used in the crafting of beer, such as barley and hops, are often treated with pesticides to reach good yields and reduce the losses during storage by protecting the plants from insects and pests. Herbicides are also used to protect the plants from weeds. One herbicide, glyphosate, which is a known carcinogen, has been recently found in 14 beers, which included beers from major brands like Budweiser, Guinness, Samuel Adams, etc. These pesticides and herbicide agrochemicals can persist in the plants for a long time and could be carried over to the beer from raw materials, malt and hops. As a result, it is important to be able to detect pesticide and herbicide residues in the finished beers. Here we describe a high throughput analytical method that employs Direct Analysis in Real Time combined with mass spectrometry (DART-MS) for detecting pesticides in beer. Craft beers are spiked with various concentrations of glyphosate and pesticides such as azoxystrobin, flonicamid, metalaxyl, and imidacloprid to simulate finished beer containing pesticides. Beers are sampled using a liquid handling robot and deposited on a wire mesh consumable for automated analysis by DARTMS. Limit of detection is determined for each pesticide. Chemometric models are created and employed to determine beers that contain trace amounts of pesticides. These beers containing pesticides are then searched against our DART-MS library database to identify the specific pesticides. This method can be potentially used to monitor pesticides in finished beer products.The plants that produce the main agricultural ingredients used in the crafting of beer, such as barley and hops, are often treated with pesticides to reach good yields and reduce the losses during storage by protecting the plants from insects and pests. Herbicides are also used to protect the plants from weeds. One herbicide, glyphosate, which is a known carcinogen, has been recently found in 14 beers, which included beers from major brands like Budweiser, Guinness, Samuel Adams, etc. These pesticides and herbicide agrochemicals can persist in the plants for a long time and could be carried over to the beer from raw materials, malt and hops. As a result, it is important to be able to detect pesticide and herbicide residues in the finished beers. Here we describe a high throughput analytical method that employs Direct Analysis in Real Time combined with mass spectrometry (DART-MS) for detecting pesticides in beer. Craft beers are spiked with various concentrations of glyphosate and pesticides such as azoxystrobin, flonicamid, metalaxyl, and imidacloprid to simulate finished beer containing pesticides. Beers are sampled using a liquid handling robot and deposited on a wire mesh consumable for automated analysis by DARTMS. Limit of detection is determined for each pesticide. Chemometric models are created and employed to determine beers that contain trace amounts of pesticides. These beers containing pesticides are then searched against our DART-MS library database to identify the specific pesticides. This method can be potentially used to monitor pesticides in finished beer products. Poster Category: Chemical Contaminants and Residues Poster Number: CHCR-03 Coauthors Brittany Laramee, Ionsense, Inc. Taylor Feraco, NeXeP LLC. Paul Liang, Ionsense, Inc. Brian Musselman, Ionsense, Inc. The analysis of polar anionic pesticides and contaminants by a new single, multi-analyte, robust and sensitive ‘sample-to result’ IC-MS/MS workflow Dan Quinn, Fausto Pigozzo, Richard Fussell, and Qilei Guo Corresponding Author Dan Quinn, daniel.quinn@thermofisher.com Thermo Fisher Scientific Abstract The introduction of the commonly used Quick Polar Pesticides (QuPPe) Method was a major step forward, but it is still analytically challenging almost 10 years later. The absence of a liquid partitioning and/or solid phase clean-up steps result in high concentrations of matrix co-extractives. This IC-MS/MS workflow addresses this issue with high capacity ion exchange columns that withstand higher sample loading enabling improved detection limits for polar analytes in difficult matrices, such as cereals and cereal products. This poster describes the development and validation of a new integrated ‘sample to results’ workflow for a reliable and sensitive quantitation of polar anionic pesticides in food. The workflow uses a high capacity ion exchange column with post column eluent suppression coupled to a high sensitivity triple quadrupole mass spectrometer (IC-MS/MS). This development is important because polar anionic