The quality and safety of all types of food products is already a major issue around the world, and is becoming even more of an issue as populations grow and stretch already strained global food supplies even further. Such factors are driving the growth of analysis techniques, of which one of the more significant is gas chromatography–mass spectrometry (GC-MS). Analysis of pesticide residues is by far the largest application area for GC-MS in food testing, but other potentially harmful contaminants, such as melamine, are adding to demand for such testing.
GC-MS has developed into a common analytical technique in the agriculture and food industries due to its ability to separate and clearly identify many of the compounds of interest. Despite the improvements in single quadrupole and time-of-flight GC-MS instruments, they lack the MS/MS capabilities found only in ion trap GC-MS instruments. Such capabilities are necessary when dealing with complex food matrices and harder to identify contaminants. However, a number of triple quadrupole GC-MS instruments have recently been introduced, or will be introduced within the next few months. Such configurations combine the strength of MS/MS for identification confirmation with the sensitivity of quadrupole mass analyzers.
GC-MS is used for the detection and analysis of pesticide residues mostly in fruits and vegetables. Although LC-MS is also used for such analyses, most of the more recently developed pesticides are designed to breakdown more rapidly, and have lower molecular weights, which generally makes them more suited to gas phase separations.
The contamination of pet food and milk products with melamine has garnered considerable media attention in the past year. The spiking of such products with melamine is intended to trick conventional food analysis methods, such as the Kjeldahl method, that test for nitrogen levels, but cannot differentiate between organic nitrogen and melamine-based nitrogen. GC-MS, on the other hand, can specifically identify the presence of melamine. While analytical work-arounds are being developed to address melamine, GC-MS offers the specificity to be able to identify a wide range of food contamination problems that could arise. There are also developments in LC-MS for melamine identification.
Although Agilent Technologies is by far the leading vendor in the GC-MS food analysis market, the top five vendors, which also include Thermo Fisher Scientific, Shimadzu, Varian and PerkinElmer, also have quite a strong presence in food analysis. Combined, these five vendors account for around 80% of the market. The worldwide market for GC-MS in food analysis is expected to be more than $90 million in 2008 (including both GC and MS portions), and should see mid-single digit growth in demand, thanks in large part to timely issues such as melamine.
GC/MS in Food Testing
at a Glance:
• Pesticide Residues