[Determination of amino acid contents in cotton-seed-cake powder]

In this work, the contents of amino acids in three kinds of cotton-seed-cake powder from domestic and abroad were determined by using Waters Automatic Amino Acid Analyzer with post-column derivatization and fluorescence detection. The operating conditions were cation exchange resin column, 250 mm x 4.6 mm i.d., gradient elution, detection wavelength lambda(ex) = 338 nm and lambda(em) = 425 nm. The results showed that contents of amino acids from both domestic cotton seed cakes were less than those from abroad.