Well over half of the chemicals in any laboratory is over five years old.
Which explains exactly why the package now states that the chemical is best used within five years, the wonderful world of mass marketing has come to scientific products ::) If the customers replace a small percentage of the chemicals due to this nonsense, then the company profits handsomely ;)
http://www.sigma.sial.com/sigma/proddata/e9508.htm (http://www.sigma.sial.com/sigma/proddata/e9508.htm)
. I've noticed that some of our liquid amines slowly darken after opening, even when stored in the dark, perhaps due to slow formation of polymeric degradation products after exposure to the air. Triethylamine, on the other hand, is much more stable. I have some ancient triethanolamine that still looks fine.http://www.loganclaypipe.com/reactive.htm (http://www.loganclaypipe.com/reactive.htm)
) but with chlorines present this is obviously a polymer with much greater reactivity.