The sample was mixed with norleucine as the internal standard, then derivatized with phenylisothiocyanate (PITC) and analyzed on a Kromasil C 18 column at 38 ℃, using gradient elution with detection at 254 nm.
以正亮氨酸为内标物 ,异硫氰酸苯酯为柱前衍生剂 ,用C18色谱柱在柱温 38℃下采用二元梯度洗脱 ,于 2 5 4nm波长处检测。
