Study on determination of tryptophan in feedstuff by high performance liquid chromatography

A method for the determination of tryptophan in feedstuff was established by high performance liquid chromatography.The samples were extracted with lithium hydroxide solution.The analysis was carried out on a C18 column with acetate buffer and acetonitrile in gradient elution.The analytes were detected with DAD detector,at280 nm as detection wavelength.The linear ranges was good from 25 mg / L to 500 mg / L with correlation coefficient0.9998.The standard addition recoveries were 88.33% ~ 105.04% and the relative standard dviation( RSD) were2.80% ~5.97%.The detection limit of tryptophan was 18.3 mg / kg.The established methods were proved accurate and reliable,which can be used for the detection of tryptophan in feedstuff.