Flavonoids 分子量、分子式的确定 Molecular ion----the m value of the molesular ion 1度0 gives the molecular weight of the compound m/e 120 M+1 peak or M+2 peak-often occurs because are naturally isotopes of cabon,or othe atoms High-Resolution Mass Spectrometry can determine the exact molecular mass of a HR-FAB-MS fragment with a precision of0001 amu. .eg.Some compounds with a nominal molecula mass of 122 amu and their exact molecular masses =18 益r容/，壳5ca18962 C9HI4 C7HION2 CSHI0O C7H602 C4H1004 C4HI0SZ 122109612.0845122.073212.036812.057912.025 m=824 Rmk-=189 YO. > 7 37 O O RDA C O O + / 或 + · m/e 120 m/e 104 Flavonoids Flavonoids 38 分子量、分子式的确定 • Molecular ion ---- the m/z value of the molecular ion gives the molecular weight of the compound • Base peak ---- is the one with the greatest intensity. ( it is assigned a relative intensity of 100% ) • M+1 peak or M+2 peak ---- often occurs because there are naturally isotopes of carbon, or other atoms 39 • High-Resolution Mass Spectrometry HR-MS can determine the exact molecular mass of a fragment with a precision of 0.0001 amu. • e. g. Some compounds with a nominal molecular mass of 122 amu and their exact molecular masses C9H14 C7H10N2 C8H10O C7H6O2 C4H10O4 C4H10S2 122.1096 122.0845 122.0732 122.0368 122.0579 122.0225 40 O OAc AcO H OAc OAc OAc AcO O OAc O OAc m/z = 824 m/z = 189 HR-FAB-MS U = C + 1 2 H N U = 18 Cal. 847.3153 Cal. 189.0552 41 LOLITA, QS-1162-2(695),HCCinn 24-Apr-2003 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000 0 m/z 100 % m938 1 (3.008) AM (Cen,5, 80.00, Ht,14000.0,0.00,2.00); Sb (1,80.00 ); Sm (SG, 2x3.00) 1: TOF MS LD+ 696.3748 x10 749 134.0985 127.1512 79.0629 636.3531 263.1783 261.1297 172.0396 194.1174 281.1890 594.3425 305.1557 441.0148 321.1306 323.2004 419.3154 379.0934 516.3113 443.0145 465.2244 576.3318 637.3569 718.3547 734.3304 735.3339 861.0693877.0446 736.3329 737.3308 841.4354 878.3107 923.3710 925.3757 Claculated values for C39H53NO10 +H 696.3747 C39H53NO10Na 718.3567 C39H53NO10K 734.3307 N O NH HO C11H16NO2 + Calculated Mass: 194,1181 C9H12N+ Calculated Mass: 134,0970