Pet Poisoning Whodunit: Melamine Increases Wheat Protein Level Readings

April 5, 2007

One subject that's apparently being discussed in some near infrared (NIR) spectroscopy chat rooms (places where I do not dare to tread) is the subject of NIR, gluten and wheat.

An expert source informs me that melamine polymers can "fool" NIR devices into recording a higher level of protein in wheat.  Melamine monomer is toxic"¦and is believed to be behind the recent gluten poisonings and pet deaths from tainted cat and dog food.  Which raises the issue:  was melamine added knowingly, by those selling the grain, or by another agent further down the distribution chain? Apparently, the expert says, this has happened for years. "Farmers used to hose down the wheat because they were paid by the ton. NIR was used because a Kleldahl nitrogen was done for the protein (can also be fooled by melamine which is 2/3 nitrogen by weight) and Karl Fischer was done for water. Both are time-consuming analytical processes. One NIR can do both in seconds"¦in fact, since the later 1970s, early 1980s, all grain sold overseas was shipped from the US after being analyzed by NIR. Unfortunately, the C=N-N-H of melamine is close enough to protein amides to fool the simple filter instruments used. "  The pharma distribution chain is also open to adulteration risks, and stories like this are playing out every day, all over the world, only we can't yet assess the size of the problem. It's technologies like NIR that will help keep supply chains safe. AMS

One subject that's apparently being discussed in some near infrared (NIR) spectroscopy chat rooms (places where I do not dare to tread) is the subject of NIR, gluten and wheat.

An expert source informs me that melamine polymers can "fool" NIR devices into recording a higher level of protein in wheat.  Melamine monomer is toxic"¦and is believed to be behind the recent gluten poisonings and pet deaths from tainted cat and dog food.  Which raises the issue:  was melamine added knowingly, by those selling the grain, or by another agent further down the distribution chain? Apparently, the expert says, this has happened for years. "Farmers used to hose down the wheat because they were paid by the ton. NIR was used because a Kleldahl nitrogen was done for the protein (can also be fooled by melamine which is 2/3 nitrogen by weight) and Karl Fischer was done for water. Both are time-consuming analytical processes. One NIR can do both in seconds"¦in fact, since the later 1970s, early 1980s, all grain sold overseas was shipped from the US after being analyzed by NIR. Unfortunately, the C=N-N-H of melamine is close enough to protein amides to fool the simple filter instruments used. "  The pharma distribution chain is also open to adulteration risks, and stories like this are playing out every day, all over the world, only we can't yet assess the size of the problem. It's technologies like NIR that will help keep supply chains safe. AMS
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