Mass spectrometry technique will play more and more role in the field of sequence analysis . standard amino acid thiohydantoins are required as reference standard for development of c - terminal protein sequencing based on the thiohydantoin procedure 在蛋白质c端(异)硫氰酸法顺序测定技术中，标准氨基酸乙内酰硫脲( th - aa )的制备是必须首先要解决的问题。
