Food Safety Magazine

TESTING SOLUTIONS | August/September 2009

A Solution for Ever-exacting Standards

By Thermo Scientific

A Solution for Ever-exacting Standards

To comply with ever more exacting food safety requirements, food safety testing organizations must find technologies that meet a variety of increased performance thresholds, but are also affordable and easy to use. The challenges the food industry faces include:

•    Testing for a growing number of chemical residues at lower maximum residue limits (MRLs) in a large number of complex food matrices

•    Decreasing the cost per analysis despite the need for a higher-end technology solution to meet performance requirements

•    Training personnel to run advanced systems

•    Performing untargeted analyses to prevent incidents such as melamine contamination of milk

A new LC-MS solution that can meet all of these challenges is the Thermo Scientific Exactive, the first non-hybrid, benchtop mass spectrometer to be powered by the award-winning Orbitrap™ mass analyzer technology.

This instrument uses high-resolution accurate mass spectrometry to provide fast, reproducible, precise results. Its ability to perform compound identification, high-throughput screening, and qualitative and quantitative analysis in virtually any matrix makes it an ideal solution for food safety testing.

Identify Compounds in Complex Matrices
A growing record of successful experiments has shown that the ability to perform high-resolution LC-MS analysis is the key to measuring accurate mass, identifying molecular structure and quantifying complex samples. All these capabilities are critical to success in a regulated industry.

Just as photographs will look blurry if the resolution is not high enough, molecular mass measurement will be inaccurate and identification will be impossible if the resolution is not sufficient. This instrument offers up to 100,000× resolution for complex sample analysis, the highest resolution available in a benchtop mass spectrometer, enabling users to perform high-resolution analyses for routine applications for the first time. It is ideal for online LC-MS analyses, enabling separation of isobaric peaks and thereby correct identification of the target compound within the specified instrument mass accuracy.

High resolution is critical for accurate analysis under several conditions likely in food, such as when low and high concentrations are present in the same sample, or where there is a complex background matrix. High resolution is also essential for enabling the determination of elemental compositions, or for performing quantitation.

Screen for Unknown Compounds
The Exactive can also be used to analyze multiple compounds, especially where the compounds may be unpredictable or unknown, another feature that makes the system ideal for increasingly complex food safety analysis requirements.

A typical method setup for the identification of unknown compounds uses alternating full MS and higher-energy collision dissociation scans, providing accurate masses of the precursor and fragment ions. It provides full-scan cycles with polarity switching in less than one second, enabling confirmation of targeted compounds and identification of unknown species in the same analysis.

The mass accuracy is precise in both polarities independent of the experiment mode, demonstrating excellent mass accuracy even with external mass calibration.

Minimize Training Requirements
As an easy-to-use benchtop system, this system is ideal for non-mass spectrometry specialists performing the kind of routine screening and compound identification applications typically found in food safety laboratories.

This instrument streamlines many of the technical steps that normally require specialized setup and operation. An intuitive software interface makes the system user-friendly in both expert and “walk-up” mode, while ensuring precise mass identification of target compounds over a wide concentration range.

Reduce Cost and Analysis Time with High Throughput
One of the greatest challenges food producers face is maintaining production levels while meeting increased screening requirements. Ultra-high-performance liquid chromagraphy (UHPLC) can help solve this problem by increasing the speed of analysis, but chromatographic peak widths of less than 1 second require an equally fast detector.

This mass spectrometer delivers up to 10 data points/second with every scan, giving analytical mass data with the correct answer and elemental composition. Excellent mass accuracy (< 2 ppm) is obtained at all scan speeds using external mass calibration. Equally good results are achieved at the base of the HPLC peak and at the peak top, which is important for ensuring accurate mass results with fast chromatography. This performance characteristic allows the use of single scans rather than averaging several scans across a chromatographic peak.

A Solution for Ever-exacting Standards
High-performance mass accuracy and high resolution provide meaningful results in analysis for difficult food matrices. This instrument packages professional-grade research technology in an easy-to-use, affordable system, making it an ideal solution for the many challenges the food industry is facing.