Using Direct Mass Spectrometry to Verify Product Authenticity

Since high quality meat demands premium prices, producers of meat-based products might be tempted to blend these products with lower cost meat, cuts from the same animal, or other bulking agents. Moreover, the labelled meat contents may no longer be met. All three types of adulteration are difficult to detect in processed products and lead to deterioration of product quality. REIMS has successfully been used to measure meat quality, fraud, and safety, including determination of species, country of origin, and substitution with cheaper cuts of meat.

Although REIMS is rapid and simple to use, the technology is coupled to a high-resolution mass spectrometer (HRMS), which may prove prohibitive for most point-of-control testing. REIMS has been installed and used effectively in an abattoir to detect boar taint, demonstrating that this is a technology that has practical potential to be used closer to the points of production and control if the costs can be reduced. However, there are innovative solutions being explored on the potential of other ambient ionization techniques, but fitted to a compact, easy-to-use nominal mass detector, which has greater potential for deployment away from the research laboratory environment.

Atmospheric Solids Analysis Probe (ASAP)

There are other types of ambient ionisation, for example, ASAP, which has recently been interfaced to a much simpler mass detector to provide a new, low-cost, dedicated direct analysis MS system. The sample or a related solution is simply applied to the glass capillary probe of the ASAP under controlled heating without any significant sample preparation. Upon thermal desorption at high temperatures, the vaporized molecules are ionized at ambient pressure before entering the mass spectrometer.

Although the MS-generated results from the ASAP are not the same as REIMS and comprise ions from a lower molecular mass range, there remains enough information to generate reliable models. As a proof of concept, the system has been used to generate multivariate statistical models for the detection of substitution fraud in dried oregano. The results from the validation study demonstrate the capability of the solution as an accurate, robust, and routine screening tool for the real-time recognition of adulteration in herbs. There are also investigations underway looking at the performance of this dedicated, compact, direct MS platform for other applications, including cocoa butter quality control, detection of fraud in edible oils, and mislabelling of honey. The data from this simple mass detector, when combined with multivariate statistics, proved able to rapidly differentiate sample types with good accuracy.

Direct MS enables rapid discrimination and classification of different raw ingredients and foods or feed using multivariate statistical reference models to quickly screen samples for signs of fraud. The absence of any sample preparation of chromatography steps when combined with a simple results dashboard makes results possible in seconds, thus speeding up decision making. It can be used for classification, to give immediate yes/no decision making, so the technique is of interest for point-of-control testing, bringing the analysis closer to the point of production, or at critical points in supply chain. There is a growing range of applications across food, meat, and crop sciences.

Dr. Hird is a principal scientist at Waters Corporation in the U.K. Reach him at [email protected].