Instrumentation

Amino acid analysis is performed on a Hewlett Packard AminoQuant II system. The system consists of a Hewlett Packard 1090 liquid chromatograph that is equipped with a programmable autosampler for automated sample handling, derivatization and injection, a diode array detector for low-moderate sensitivity (ultraviolet detection) analyses and an in-line Hewlett Packard 2400 fluorescence detector for high-sensitivity analyses (fluorescent detection). All system control and data analysis is performed by a Hewlett Packard 2-Dimensional Chemstation. Liquid and vapor phase hydrolysis protocols have been developed in order to service a wide range of sample types (liquid, dried and electroblotted proteins on membranes). We offer routine validated (qualitative and quantitative) amino acid compositions of purified proteins and synthetic peptides as well as (quantitative ) free-amino acid (or total amino acid) compositions of feeds, flours and physiological fluids. Hydrolyzed proteins samples and free amino acids are derivatized pre-column with o-phthalaldehyde (OPA) and 9-fluoromethyl-chloroformate (FMOC) prior to separation and quantitation by reverse phase HPLC. Sensitivity is in the picomole to nanomole range depending upon sample matrix contributions.