Advances in the analysis of amino acid phenylthiohydantoins by high performance liquid chromatography

All the organic soluble amino acid phenylthiohydantoins are eluted (but not totally resolved) in under 40 min on either a Zorbax ODS or Permaphase ETH column. The superior resolution of the Zorbax ODS column and the complimentary characteristic of the Permaphase ETH column allow the isocratic analysis of 15 phenylthiohydantoins in less than 20 min when the columns are operated simultaneously. The water soluble PTH-His and -Arg are analyzed separately in under 10 min with the Zorbax ODS column. Five picomoles of a derivative may be detected with a sample to noise ratio of 6, HPLC is the most sensitive, practical method for PTH analysis.