Racemization
（重定向自Racemisation）
In chemistry, racemization is the conversion of an enantiomerically pure mixture (one where only one enantiomer is present) into a mixture where more than one of the enantiomers are present. An enantiomer, also known as an optical isomer, refers to a stereoisomer of a pair of molecules that are non-superimposable mirror images of each other. If the racemization results in a mixture where the D and L enantiomers are present in equal quantities, the resulting sample is described as a racemic mixture, a racemate, or racemic.