Ys ext 9050 MD uses high performance liquid chromatography tandem mass spectrometry (LC-MS / MS), High resolution and high efficiency of high performance liquid chromatography are combined with high sensitivity and high selectivity of mass spectrometry. Finally, accurate quantitative analysis is realized by internal and external standards of isotopes. Clinically, it can be used for more than 70 detection items such as genetic metabolic diseases, vitamins, hormones, fatty acids, amino acids, bile acids, therapeutic drugs, etc.