Thin layer chromatographic estimation of available lysine in dried milk powder

A rapid method for the estimation of available lysine in dried milk powder has been developed. Samples were treated with 2,4,6-trinitrobenzene sulfonic acid and then hydrolyzed with 6N HCl. The hydrolysate was purified and subjected to ascending thin layer chromatography to isolate xi-trinitophenyl lysine in pure form. The color was read at 346 nm in a specitrophotometer.