Use of infrared multiphoton photodissociation with SWIFT for electrospray ionization and laser desorption applications in a quadrupole ion trap mass spectrometer
Use of infrared multiphoton photodissociation with SWIFT for electrospray ionization and laser desorption applications in a quadrupole ion trap mass spectrometer
复制标题
DOI：
10.1021/ac9600565
复制
发表时间：
1996-11-15
影响因子：
7.4
通讯作者：
Brodbelt, J
中科院分区：
文献类型：
--
作者：
Colorado, A;Shen, JXX;Brodbelt, J
在四极杆离子阱质谱仪中，将红外多光子光解（IRMPD）与存储波形傅里叶逆变换（SWIFT）相结合，实现了电离和离子喷射。IRMPD的应用化学电离和电喷雾电离产生的生化离子的结构表征和利用红外光子的激光解吸金属离子冠醚配合物的活化的可行性进行了研究。研究了氦压力对已知热化学体系的解离效率和相对解离速率常数的影响。当使用低于2 × 10（-5）Torr的标称压力时，氦气压力对IRMPD实验无害。在接近标称8 × 10（-5）托氦的压力下，碰撞失活占主导地位。结果表明，传统的CAD是一种更有选择性的解离技术，然而，产生的碎片离子信息的量高度依赖于qz值。另一方面，IRMPD与qz的值无关，使得在照射期间可以利用低rf存储值。因此，在这些条件下，捕获并检测信息性较低质量碎片离子。相对于CAD方法，在用红外光子照射时产生大量的结构信息片段，这是因为在光吸收时初级碎片离子的进一步激发。SWIFT波形被成功地用于确定初级碎片离子的激发程度，以及证明/证伪各种离子如大环内酯类抗生素和氢键复合物的解离途径。
Infrared multiphoton photodissociation (IRMPD) is combined with stored wave form inverse Fourier transforms (SWIFT) to effect dissociation and ion ejection in a quadrupole ion trap mass spectrometer. The application of IRMPD to the structural characterization of biochemical ions generated by chemical ionization and electrospray ionization and the feasibility of utilizing infrared photons for the activation of laser-desorbed metal ion-crown ether complexes was examined. The effect of helium pressure on the dissociation efficiency and relative dissociation rate constants for systems with well-known thermochemistry was evaluated. The helium pressure is not detrimental to the IRMPD experiment when nominal pressures lower than 2 x 10(-5) Torr are used. At pressures close to nominally 8 x 10(-5) Torr of helium, collisonal deactivation dominates. Results show conventional CAD is a more selective dissociation technique; however, the amount of fragment ion information generated depends highly on the qz value. IRMPD, on the other hand, is independent of the value of qz such that low rf storage values can be utilized during the irradiation period, Thus, under these conditions, informative lower mass fragment ions are trapped and detected. A larger number of structurally informative fragments is generated upon irradiation with infrared photons relative to the CAD method because of the further excitation of primary fragment ions upon photoabsorption. SWIFT wave forms are successfully utilized to determine the extent of excitation of primary fragment ions as well as prove/disprove dissociation pathways of a variety of ions such as macrolide antibiotics and hydrogen-bonded complexes.