EXPANDING THE SCOPE OF CHEMICAL DETECTION FOR FOOD SECURITY AND SAFETY
Residue Chemistry and Predictive Microbiology
2012 Annual Report
1a.Objectives (from AD-416):
To challenge the feasibility of the system prototype by conducting side-by-side confirmatory analyses of shared samples with the U. of Kentucky cooperator using state-of-the-art lab-based techniques (advanced chromatography and mass spectrometry). For sample preparation, the QuEChERS method will be employed for a wide range of potential analytes and matrices. This method can be adapted for the analysis of identified marker molecules in target matrices to counter possible food security threats.
1b.Approach (from AD-416):
University of Kentucky PI is using proprietary chemical-based methods to detect chemicals in a variety of food samples. ARS shall collaborate in a “red team – blue team” approach in which ARS will be the red team. The red team is tasked with challenging the blue team with possible scenarios that should be covered by the blue team’s monitoring system, and the blue team must address the challenge or adapt to it. After initial testing and method validation, a double-blind study will be conducted to assess the system performance and readiness for official testing.
The goal of this project is to evaluate the QuEChERS approach for sample preparation in the laboratory-based analysis of lettuce and ground beef fortified with 2-butylaminoethanethiol (BAET), a chemical warfare agent simulant, and Lipid A, an endotoxin. These are analytically challenging representative chemicals and matrices designed to put a test to the QuEChERS approach for food security/defense applications. For analysis, a supercritical fluid chromatography (SFC) system, an upgrade to an existing HPLC instrument was obtained and coupled to an ion trap mass spectrometer (MS/MS). Also, a post-doctoral scientist was hired to help conduct experiments and participate in red team–blue team exercises associated with this grant project. In the latter activities, meetings with team members and collaborators were made on separate occasions, including follow-up discussions and reports. In the laboratory, the conditions for analysis of BAET and Lipid A were optimized using SFC-MS/MS, which involved evaluation of several different chromatographic columns, mobile phase, and detection conditions. For sample preparation, the original QuEChERS method was shown to work well for BAET, but Lipid A requires unique conditions. Further work to optimize sample preparation conditions based on QuEChERS concepts is being investigated to enable simultaneous analysis of both analytes in the targeted food commodities.