Tryptophan Determination in Tissue Homogenates and Biological Fluids Using HPLC-EC

Abstract
A method for quantitating tryptophan in [human] tissue homogenates and biological fluids using 6-hydroxy-tryptamine as internal standard is described. Tryptophan in CSF and free tryptophan in serum or plasma can be quantitated by directly injecting CSF or ultrafiltrate into the HPLC system with the internal standard. Serum, plasma, amniotic fluid, and saliva are deproteinized by addition of equal volume of acetonitrile. Urine samples are processed through Biorex-70 columns. Cross validation was done by comparing the values of column procedures with direct injection method.