Advances in LC/MS for Food Safety Testing

Great progress has been made toward applying more universal sample preparation to LC/MS/MS analysis. The QuEChERS (quick, easy, cheap, effective, and safe) extraction technique for extracting pesticides from food and feeds takes advantage of the sensitivity and specificity of LC/MS/MS for multi-residue pesticide screening and has the potential to be applied to a broader range of contaminants.⁴

Better Compound Coverage

Globalization of the food supply has necessitated screening for a wider range of potentially harmful substances. Raw materials and finished products alike are subject to contamination or adulterants that can originate almost anywhere along the farm-to-table pathway. Chemical testing has to cover a broader range of contaminants, and biological testing must identify bacteria and viruses that may be present in the food, as well as determine the exact serotype of each microbe, to locate the origin of the contamination.

Mycotoxins, for example, are low-molecular weight, chemically diverse toxins that are produced naturally by molds commonly found in grains and fruit and have been linked to a wide range of negative health effects. Aflatoxin, for example, is the most potent natural carcinogen known to man, and ochratoxin has been shown to damage the liver, kidney, and immune system.

LC/MS/MS is a powerful tool for the analysis of mycotoxins, because the workflow can screen for, quantitate, and identify several classes of mycotoxins in a single run, allowing laboratories to confirm the presence and structure of multiple mycotoxins and metabolites simultaneously in a significantly reduced amount of time. What used to require multiple analyses on multiple MS platforms now involves only a single LC/MS/MS run on a single system. This is not possible using technologies such as LC/UV, one of the most widely used screening techniques over the last 10 years.

In a recent multi-residue mycotoxin analysis and field study of wheat, barley, oats, rye, and maize grain, researchers at the University of Guelph, Laboratory Services Division, in Ontario, Canada were able to demonstrate a durable method for the simultaneous analysis of 22 mycotoxins in a single LC/MS/MS run using one common extraction technique rather than employing several different extractions and instruments.⁵ Further, the researchers found that “such a method offers a distinct advantage over other mycotoxin methods not only because it is cheaper and more efficient, but because it considers the toxicological relevance of the target mycotoxins.” Data generated from this study will also be used to advance the understanding of a wide range of mycotoxins, including cyclopiazonic acid, in cereals and grains and other matrices.

The FDA, which manages one of the world’s most sophisticated and far-reaching food supply monitoring programs, samples individual lots of domestically produced and imported foods and analyzes them for pesticide residues. LC/MS/MS gives the agency a technology that integrates quantitative and qualitative analysis on the same platform and performs automated identification of a wide range of contaminants simultaneously.⁶

Improved Technology

Developments in LC/MS/MS have been central to recent technology advances in food safety testing. LC/MS/MS enables laboratories not only to test for the presence of hard-to-detect toxins, but also to identify metabolites that may be formed after contamination and address the continually lowering detection limits required by global regulations. The technology is also widely applied in screening for other food contaminants such as pesticides, veterinary drug residues, marine biotoxins, and packaging materials.

Recent advances in mass spectrometry systems have significantly advanced both quantitative and qualitative analysis. The ability to quantify contaminants and obtain identification confirmation in a single run enables new levels of productivity. New levels of sensitivity and specificity allow lower levels of contaminants to be monitored and quantified with simplified sample preparation. Also, advances in high-resolution LC/MS/MS systems, complemented by new software tools, provide unique capabilities to screen for unexpected contaminants.