In 2007-2008, thousands of pets and children in North America and China became ill and some died after consuming pet foods and baby formulas contaminated with melamine and cyanuric acid. Extensive research found that melamine from Chinese wheat gluten combined with cyanuric acid to form insoluble crystals in the kidneys that caused renal failure. While melamine alone is not very toxic, when combined with cyanuric acid it created dangerous crystals. Melamine mixed with uric acid did not produce crystals. The research confirmed that cyanuric acid, not uric acid, was the co-contaminant responsible for the illnesses and deaths.

1. Dept. of Environmental and Infectious Disease Science
Michael King

2. •In 2007, there were thousands of cases of kidney- related illness in pets
across North America. The cause of illness was traced back to certain lots of
wet pet foods.
•Hundreds of cats and dogs died of acute renal failure. Water insoluble
crystals in the kidneys were found to be the cause.
•Extensive research determined melamine to be one of the main
contaminants. The contamination was traced back to a Chinese factory, which
used melamine-tainted wheat gluten. (The protein content in food is measured
in nitrogen levels, not actual protein content, hence the term “apparent protein
levels.” Food with higher protein levels can be sold for a higher price.)
Raw melamine

3.  Melamine itself is not very toxic, so researchers hypothesized the existence
of a second contaminant that would combine with the melamine to form
insoluble crystals. Cyanuric acid was found to be the second contaminant.
 In 2008, there were widespread reports of kidney illness in young children in
China. The children affected were found to be consuming melamine-tainted
baby formula.
 Over 300,000 children became ill; however, 4-10 deaths have been reported.
 Uric acid theory
-A group of researchers working in China reported that the melamine in baby
formula bonded with uric acid (a naturally occurring chemical in the urinary
system) to form water insoluble crystals.
Melamine/cyanuric acid crystal structure

4. -It has already been established that cyanuric acid will bond with melamine to
form insoluble crystals, but it seemed unlikely that the same thing would
happen with uric acid and melamine. We wanted to test if uric acid would
form crystals with melamine, and if they did we sought to obtain IR spectra
from these crystals for future reference to be able to identify the crystals in
patients.
-We wanted to examine the melamine-cyanuric acid crystals to see if an excess
of either compound would change the crystal composition. We planned to
use GC-MS to evaluate the crystal composition.
Uric acid Cyanuric acidMelamine

5.  -Smiths Illuminat IR II (IR spectrometer)
 -IR Microsystems molecular analysis system (IR spectrometer)
 -Agilent Technologies 6890N GC system (Gas chromatography device)
 -Agilent Technologies 5975 mass selective detector (Mass
spectrometer)
 -Agilent Technologies 7683 series autosampler
 -IEC centra CC2 centrifuge
 -Eppendorf research pipettes [200 micro liters, 1000 micro liters]
 -Fisherbrand 5 ¾ “ disposable Pasteur pipettes
 -TurboVap LV evaporator
 -Olympus BX51 (Light microscope)
 -S-3400N Hitachi Scanning Electron Microscope

6. • Mixed different concentrations of melamine and cyanuric acid (at
room temperature)
• Mixed melamine and uric acid (at room temperature)
• Mixed melamine and uric acid (at 37˚C , body temperature)
• Mixed melamine and uric acid (at pH 6 and pH 10)
• Mixed melamine and uric acid, then added cyanuric acid (at room
temperature)
• Analyzed the solutions with IR spectroscopy and/or GC-MS

7.  Every solution of melamine and cyanuric acid formed
new crystals. All of the new crystals were collected and
scanned using IR spectroscopy. The IR spectra all looked
similar and the GC-MS data suggested a nearly constant
ratio.
 None of the melamine/uric acid solutions formed new
crystals. Any crystals present were found by IR
spectroscopy to be uric acid only.
 It was found that uric acid is insoluble in water, unless the
solution is at basic pH levels.

8. Example of a melamine/cyanuric acid crystal chromatogram
Ratio (ca/m) CA average area Mel. average area ReRatio (CA/M)
*90/10* 689758 1203297 0.573223402
*70/30* 2671438 3603430 0.74135976
*50/50* 6544769.5 7778200.5 0.841424633
*30/70* 2594576.5 5109277 0.507816762
*10/90* 904972 1487489.5 0.608388832
•Ratios are similar
Cyanuric acid Melamine

9. Cyanuric acid mass spectrum
Melamine mass spectrum

10. •Melamine and cyanuric acid are water soluble
•When mixed they form water insoluble crystals (shown in bottom spectrum)
•Bottom spectrum matches spectra from pet kidney tissue

11. •Solid collected after mixing melamine and uric acid
was found to be uric acid

12. • The results of this project point to cyanuric acid being the
agent which bonded with the melamine in pet food to form
water insoluble crystals.
• The results also show it is unlikely that melamine from the
baby formula bonded with uric acid to form insoluble crystals
in the babies’ kidneys.
• Bearing this in mind, the reported composition of uric
acid/melamine crystals is likely erroneous.

13.  Why should we care?
-Increasing amounts of imported food
-Processed food has bulk ingredients
 Many brands could be tainted
-Food tainting is a common problem
-Despite the efforts of the FDA inspections, contamination may happen
again
 How does knowing help?
 ”A pound of cure is worth an ounce of prevention”
-Doctors know what they’re dealing with (Better, faster treatment)
-FDA officials and Investigators know what to look for

14. I give many thanks to the following people;
 Dr. Mullick- For making this program possible
 Dr. Kalasinsky- For being an excellent mentor, for showing me the way
 Dr. Lewin-Smith- For being another excellent mentor, for the ride and for
heading the slide conferences
 Ms. Laura Burry- For being a great teacher, for helping me in the lab
 Ms. Marie Jenkins- For her kindness, for letting me use her centrifuge, and
for her stories
 Ms. Lynn Blubaugh- For being another great teacher, for showing me how
to use the SEM
 Ms. Leslie Middleton- For organizing everything, and for your patience,
time, and reminders
 Ms. Stacy Strausborger- For teaching me how to do molecular calculations
 The Environmental department- For their kindness, patience and positive
attitude