I'm more concerned about the stuff in HFCS that is not sugar, than I am about the relative mix of fructose to sucrose. The trace amount of mercury, the other chemicals identified on the spectragraph, and there is also a particle that has been found in the blood of diabetics that is found in HFCS, but I've lost the link on it.
The IATP study that found mercury in products using HFCS was, like so many others, seriously flawed. They never employed a control group so we really have no idea whether the mercury came from the HFCS or something else.
The highest concentration of mercury found was measured at 350 ppt - that's parts per trillion. Measuring in picograms is just plain silly. There is nothing to be worried about when an element is found in quantities in less than 400 parts per trillion. Good grief, you can find mercury in drinking water at 500 ppt and no one is running and screaming into the night about it.
As a matter of fact, higher concentrations of mercury can be found in many fruits and vegetables. Canned mushrooms were found to contain mercury - at least in one test - at 5,000 - 15,000 parts per trillion. Scary. You're probably exposed to thousands of times more mercury when you screw a fluorescent light bulb into a socket.
The compounds you are not remembering are called a reactive carbonyls. These carbonyls are found at high levels in the blood of diabetics. They are also found in drinks sweetened with HFCS. The guy conducting this reasearch (Dr. Ho @ Rutgers) is a top shelf researcher so there may be something to this. Or it may be much ado about nothing.