Leaf pepper tissue (0.05 g) was ground in 3% sulfosali-cylic acid,
the homogenate was filtered,
and 0.75 mL glacial aceticacid,
and 0.75 mL ninhydrin reagent (1.25 g ninhydrin in 30 mLglacial acetic acid and 20 mL 6 N phosphoric acid)
were added to an aliquot of the filtrate.