I purchased (S)-(-)-1-phenyl-1-propanol and (R)-(+)-1-phenyl-1-propanol from Aldrich and tested these chamicals with HPLC system with CSP (using methanol for mobile phase).
Strangely, two peaks appeared even in pure enantiomers. I also tested with racemic mixture and checked two peaks at same retention times as pure enantiomers.
Is it contaminated or is it possible that two peaks appear from pure enantiomer?

What column are you using?

Dear Ki Bong;

Your results suggest several posibilities. I will assume that you are using a Chiral resolution column. It is alltogether possible that your "pure enantiomers" are not really pure (I have seen cases like these), but then when you inject each one, the peak ratios should not be 1:1 unless they are grossly mislabeled. If they are 1:1 ratios (or closely to 1:1) that would indicate that each one is a racemic mixture. The easiest thing to do about this problem is first to inquire with the supplier about their purity checks, i.e. specific rotation.

The other possibility is that each one is contaminated with a chemical impurity that is resolved by chance in your chiral column.

Another, more remote possibility, is that each enantiomer racemizes in solution. I do not know whether this is possible with your compounds. But then unless the racemization is instantaneous, you should see a change in area ratios doing progressive inyections as a function of time.

Good Luck;

Benjamin