Amino Acid Analysis

The AminoQuant analyzes peptides and proteins by pre-column derivatization of hydrolyzed samples with o-phthalaldehyde (OPA) and 9-fluoromethyl-chloroformate (FMOC). OPA reacts with primary amino acids and FMOC with secondary amino acids (proline). Both reagents react rapidly and quantitatively and give highly fluorescent and UV-absorbing isoindole derivatives. The derivatized amino acids are separated by reverse phase HPLC and detected by UV absorbance with a diode array detector or by fluorescence using an in-line fluorescence detector.

Routine samples are mixed with internal standards (see Quantitation), dried in glass tubes in a vacuum concentrator and subjected to vapor phase hydrolysis by 6N HCl at 110ºC for 24 hours under argon atmosphere in the presence of phenol. The samples are subsequently reconstituted in borate buffer and transferred to the AminoQuant autosampler for automated derivatization and loading.