MALDI-TOFMS测定高聚合度葡聚糖及不同基体在测定中的作用比较

应用基体辅助激光解吸电离飞行时间质谱(MALDI-TOFMS)直接对未经分级的高聚合度(n>100)葡聚糖样品进行了测定,检测到的葡聚糖最大分子量达18000以上.对2,5-二羟基苯甲酸(DHB)、1-羟基异喹啉(1-HIQ)及3,4-二羟基肉桂酸(咖啡酸,CA)3种一元基体以及DHB与1-HIQ,DHB与CA两种二元基体在测定中的作用进行了比较.结果表明,DHB基体测定的质量范围较大;DHB+1-HIQ和DHB+CA二元混合基体对样品的解吸电离效果及谱图重现性好;DHB+1-HIQ基体获得的谱图分辨率高.

Determination of High Polymerization Degree Dextran by Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry(MALDITOFMS) and Comparison of Matrix Effects in the Determination

A dextran sample with a high polymerization degree(n>100) was directly determined by the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOFMS) without being further fractionated and the molecular weight of the dextran up to more than 18 000 had been detected. The effects of matrixes 2,5-dihydroxybenzoic acid(DHB), 1-hydroxyisoquinoline(1-HIQ), 3,4-dihydroxycinnamic acid(caffeic acid, CA) and binary matrixes DHB 1-HIQ, DHB CA were tested and compared. The results showed that the larger mass range could be obtained when matrix DHB was used, the dextran molecules were desorbed and ionized more efficiently and the reproducibility of spectra was enhanced when binary matrixes DHB 1-HIQ and DHB CA were used, also the resolution of spectra were increased when binary matrixes DHB 1-HIQ were used.