电喷雾解吸电离质谱研究基体中直接黑与溶剂的相互作用

DESI-MS investigation of the molecular interaction of direct black dye with solvent molecules in matrix

采用电喷雾解吸电离质谱法(DESI-MS)研究了基体中酸性染料直接黑与水的相互作用,发现水与直接黑能够形成一系列比较稳定的水合物(M+nH2O,n=0～7),其中稳定性最大的水合物为n=3或4;在相同条件下,直接黑还能够与甲醇形成类似的簇合物(M+nCH3OH,n=0～7),其中最稳定的甲醇化物为n=3.实验表明在无需样品预处理的前提下,DESI-MS能够直接用于表面复杂基体内分子相互作用的研究,为复杂表面中物质的相互作用的深入研究提供了一种新方法.

Desorption electrospray ionization mass spectrometry （DESI-MS） was employed to study the molecular interaction of direct black acid dye with water or methanol on sample surfaces with matrices. At atmospheric pressure, direct black dye molecule combines with water molecule to form a series of stable hydrate（M ＋ nH2O, n = 0 - 7） while the most stable clusters are formed with the value of n to be 3 or 4. Under the same conditions, direct black dye molecule also interact with methanol to form clusters （M ＋ nCH3OH, n = 0 - 7） while the most stable clusters are generated with the value of n to be 3. Experimental data show that DESI-MS can be directly used, without sample pretreatment, for the investigation of interaction of molecules present in complex matrix surface. The experiment provides a new method for real time monitoring the interaction of molecules on surfaces with complex matrices.