Ensuring the safety of the world’s food supply is of utmost importance. Screening foodstuffs for known and unknown contaminants, such as pesticides, herbicides, antibiotics, and adulterated food, must be quick and simple, but identifying these contaminants is a challenging experiment. Analysis by mass spectrometry with high resolution and accurate mass is ideally suited for food sample screening and quantification of hundreds to thousands of contaminants in a single analysis. Orbitrap™-based mass spectrometers provide high-resolution, accurate-mass (HR/AM) capabilities with fast scanning speeds required to deliver results quickly to quarantine contaminated food and ensure only safe food is brought to the market.
For additional resources, search the Orbitrap Science Library
Overview
Workflow Overview for Unknown Screening of Food Contaminants
For the screening of unknown contaminants in food, the main goal is to identify as many contaminates present in a single sample. Typically, this workflow is very complex because there is no target list to use and other instrumentation and software are required. In a typical workflow, samples are collected, arrive at the lab, and are logged into a database, processed, and extracted using a simple, easy method. Finally, the samples are analyzed on the mass spectrometer, data is scrutinized using automated software, and the data is checked against a larger external database and further confirmed.
Resources
Shen Y, van Beek TA, et al.
J Chromatogr A. 2012 Oct 12;1259:179-86.
Crawford E, Musselman B.
Anal Bioanal Chem. 2012 Jul;403(10):2807-12.
Filigenzi MS, Ehrke N, et al.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2011 Oct;28(10):1324-39.
Sample Preparation
Sample Preparation Workflow for Unknown Screening of Food Contaminants
QuEChERS, the acronym for Quick, Easy, Cheap, Effective, Rugged, and Safe, describes a highly beneficial technique that simplifies the analysis of multiple pesticide residues in fruits, vegetables, cereals, and other food products. There are now many variations of QuEChERS; however, AOAC International has one certified method – the AOAC Official Method 2007.01, titled “Pesticide Residues in Foods by Acetonitrile Extraction and Partitioning with Magnesium Sulfate”.
In brief, the QuEChERS procedure entails extracting the pesticides using a variety of simple reagents/buffers, as well as solid phase extraction (SPE). The final extract can be analyzed directly by GC- and/or LC-based mass spectrometry. Both the extraction and cleanup can be scaled up or down as required by the sample.
Products
QuEChERS Products
Columns
Chemicals and Reagents
Resources
AOAC Official Method 2007.01
QuEChERS online information
Original QuEChERS protocol
Mass Spectrometry
Mass Spectrometry Workflow for Unknown Screening of Food Contaminants
The use of UHPLC in food sample analysis has been growing steadily to decrease the turnaround analysis time per sample. Advances in Orbitrap™ technology have been made to accommodate the requirements associated with UHPLC, namely, HR/AM and high speed.
With these benefits in mind, here are a few highlights that will help you acquire the unknown screening data in which you are most interested. Our full-scan, data-dependant MS/MS methods enable screening for unknown contaminants:
- The system rapidly and automatically performs MS/MS on the components detected in the MS spectrum with high resolution and accurate mass at a speed amenable to UHPLC.
- After data is acquired and components are identified, the data can always be re-interrogated for new compounds of interest.
- Full-scan MS and MS/MS allows confirmation of identity in the same run.
Products
Thermo Scientific Accela High Speed LC
Download the brochure
Thermo Scientific Dionex UltiMate 3000 HPLC series
Resources
Shen Y, van Beek TA, et al.
J Chromatogr A. 2012 Oct 12;1259:179-86.
Crawford E, Musselman B.
Anal Bioanal Chem. 2012 Jul;403(10):2807-12.
Filigenzi MS, Ehrke N, et al.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2011 Oct;28(10):1324-39.
Data Analysis
Data Analysis Workflow for Unknown Screening of Food Contaminants
Multiple software solutions are available for the analysis of food safety samples.
Thermo Scientific ExactFinder software is the preferred software choice for unknown contaminant screening. ExactFinder™ software has the ability to select ion peaks of interest from the full MS spectrum, assign a theoretical molecular formula based on m/z, and then search ChemSpider for identification of potential candidates.
After a putative identification of the contaminant has been made, Thermo Scientific Mass Frontier software can provide identity confirmation by using the fragment ion spectrum acquired in the data-dependent MS/MS run. Mass Frontier™ software also has the ability to show chemical synthesis breakdown patterns.
The ultimate unknown screening of samples can be accomplished using Thermo Scientific SIEVE software. SIEVE™ software takes multiple data files, processes them versus a blank sample, and looks for differences between them. By doing this, scientists can see what is in one sample that is not present in the other.
Watch the video interview: TraceFinder LC-MS Software for Food Safety and Environmental Testing.
Products
Thermo Scientific TraceFinder Software
Download the brochure
Thermo Scientific ExactFinder Software
Download the brochure
Mass Frontier Spectral Interpretation Software
Download the brochure
Sieve Differential Expression Software
Download the brochure

Resources
Shen Y, van Beek TA, et al.
J Chromatogr A. 2012 Oct 12;1259:179-86.
Crawford E, Musselman B.
Anal Bioanal Chem. 2012 Jul;403(10):2807-12.
Filigenzi MS, Ehrke N, et al.
Food Addit Contam Part A Chem Anal Control Expo Risk Assess. 2011 Oct;28(10):1324-39.
Thermo Fisher Scientific
United States
