In his Wiley Award Address, “A Rearview Mirror Perspective on 40 Years of Chasing Zero for Standard Deviation and Detection Limits,” Jonathan DeVries, senior technical manager/senior principal scientist at Medallion Laboratories/General Mills, examined the past four decades in performing analyses in food nutrition, safety, and quality. Advancing from primary tools to today’s state-of-the-art technology has certainly been exciting--yet challenging--for chemists. Although the new technologies have brought an array of capabilities to food analysts (lower detection and quantitation limits, discovery of new analytes), improved levels of precision have not kept pace. DeVries addressed the challenges that come along with analytical improvements, such as the cost of testing required--and higher variability in data--when chasing zero. Prefacing his talk on food analyses over the past 40 years, DeVries stressed that addressing issues such as food safety and security, fair trade, and food adulteration “requires some real leadership in monitoring and analysis, particularly in science, regulation, and enforcement.”

“As we make improvements in technology and are able to attain lower and lower sensitivity levels, the cost goes up,” said DeVries. “Zero is a small number with a big impact.”

Improvements in technology (instruments and methods) have indeed provided improved sensitivity and selectivity to make better decisions, but not necessarily better results in terms of precision, i.e., variability. As limits of detection approach zero, the relative standard deviation increases.

“The closer we get to zero, there are more compounds, more unknowns, and more variability in data,” DeVries said. “Despite advances in technology, analytical precision has essentially remained unchanged in 125 years.”

DeVries then went on to illustrate the use of the improved technologies in detecting and deterring economic adulteration in foods, thus reducing fraud foisted upon the consumer.

“Food adulteration is not a new or unique problem,” said DeVries, who illustrated some of the economic drivers of such fraudulent activity. Some recent examples of food adulteration include melamine/cyanuric acid in wheat gluten, melamine/cyanuric acid in dairy, and urea in wheat.

Standardized methods are needed to provide equivalent results and to ensure fair trade practices. In addition, “If methods aren’t shared, the true quality of the methods is rarely known,” said DeVries.

However, there are challenges that come along with standardized methods, such as the science can be abused. “The dilemma of standard tests is that perpetrators know what the laboratories are doing and can devise means of passing the tests.” DeVries noted that the food adulteration risk is high and “only the adulterers know the extent of the adulteration”--which leaves consumers to wonder what else may be lurking?

In the end, what is really needed is solid science to set realistic limits and valid methods to conform to limits. AOAC INTERNATIONAL continues to play a lead role, ensuring confidence in analytical results in an era of technological changes.

“From the earliest days of its formation 125 years ago, AOAC has concerned itself with establishing Official Methods of Analysis^SM for foods, in part to ensure the purity of foods,” DeVries said. “This effort still continues today through Official Methods^SM, proficiency testing, consensus building, and other AOAC programs.”

Full coverage of the Wiley Award Address is scheduled for the November/December 2009 issue of Inside Laboratory Management.

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