Surface-induced dissociation by Fourier transform mass spectrometry.
Surface-induced dissociation by Fourier transform mass spectrometry.
复制标题
通过傅里叶变换质谱法进行表面诱导解离。
DOI：
10.1021/ac00212a017
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发表时间：
1990
影响因子：
7.4
通讯作者：
Wilkins,CL
中科院分区：
文献类型：
--
作者：
Ijames,CF;Wilkins,CL
最近一个非常有前途的离子碎裂技术是表面诱导解离（SID），由Cooks及其同事于1985年介绍（1）。该技术包括加速母离子进入金属靶，然后对非弹性散射的子离子进行质量分析。在一系列论文中，这些工作者描述了使用混合磁扇形四极杆（1）、串联四极杆（2）和串联飞行时间质谱仪（3）实现SID。这些仪器提供碰撞能量高达300 eV的电子化产生的母离子和单位子离子质量分辨率。转换效率，定义为子离子丰度的总和除以母离子丰度在SID的情况下，范围从2%到15%。应该注意的是，多个分析仪仪器的这种通用定义会降低SID效率，因为它忽略了第二个和后续分析仪中母离子的大量损失。更严格的定义，将使用母离子丰度到达SID站点，给出小于1%的SID效率。在这里，表面诱导解离具有可比的效率，使用傅里叶变换质谱仪（FTMS），其中没有这样的区别，进行了描述。从分析的角度来看，SID的一个主要优点是它能够将相对较高百分比的平移能转换为内能。例如，25 eV SID的五羰基铁离子产生约4 eV的平均内能，而在相同的实验室能量下与氩气的碰撞平均存款小于2 eV（4）。平均内能随平移能增加，在140 eV的碰撞能量下达到8 eV。这大约相当于与氩原子（4）的7 keV碰撞所沉积的能量。还应该注意的是，在更高的压力下，可以在多种碰撞条件下获得类似的高效率（例如，使用三重四极杆或离子阱质谱仪的碰撞诱导解离（CID））。传统的碰撞活化串联质谱（MS/MS）的主要局限性是二次离子的产率随着母质量的增加而降低（5）。这是由于母体和目标质量的不匹配增加以及较大分子中可用的振动模式的数量增加，促进了沉积能量的内部分布，而不是解离。SID具有增加内部能量沉积的潜力，从而增加高质量离子的MS/MS的效率。这方面的证据可以在Aberth最近的报告中找到，该报告使用串联Wien过滤器仪器（6）通过二次离子质谱法产生母离子的SID。采用掠入射配置的微通道板作为目标，碰撞能量扩展到1000 eV。本文报道了分子量为555的亮氨酸脑啡肽的正、负光谱，其裂解与高能CID法相似。此外，（CsI）nCs * 被片段化以产生（CsI）nCs+离子= 0至23。这些结果表明，SID是可行的与高质量的离子在碰撞能量低至1 keV。
A recent and very promising addition to the list of ion fragmentation techniques is surface-induceddissociation (SID), introduced by Cooks and co-workers in 1985 (1). The technique consists of accelerating parent ions into a metal target and then mass analyzing the inelastically scattered daughter ions. In a series of papers, these workers have de-scribed implementationof SID using hybrid magnetic sec-tor-quadrupole (1), tandem quadrupole (2), andtandem time-of-flight mass spectrometers (3). These instruments provide collision energies up to 300 eV for electronionization-generated parent ions and up to unit daughter ion mass resolution. Conversion efficiencies, defined as the sum of daughter ion abundances divided by the parent ion abundance in the absence of SID, range from 2% to 15%. It should be noted that this common definition for multiple analyzer instruments exagerates the SID efficiency because it neglects substantial losses of parent ions in the second and subsequent analyzers. The stricter definition, which would use the parent ion abundance arriving at the SID site, gives less than 1% SID efficiency. Here, surface-induced dissociation with comparable efficiency using a Fourier transform mass spectrometer (FTMS), where there is no such distinction, is described. From an analytical standpoint, a major advantage of SID is its ability to convert a relatively high percentage of translational energy into internal energy. For example, 25 eV SID of iron pen-tacarbonyl ions yields an average internal energy of approx-imately 4 eV while collisions at the same laboratory energy with argon gas deposit less than 2 eV, on average (4). The average internal energy increases with translational energy, reaching 8 eV at a collision energy of 140 eV. This corresponds approximately to the energy deposited by a 7-keV collision with an argon atom (4). It should also be noted that similar high efficiencies can be obtained under higher pressure, multiple collision conditions (eg collision induced dissociation (CID) using a triple quadrupole or ion trap mass spectrometer).A major limitation of conventional collisional activation tandem mass spectrometry (MS/MS) is that the yieldof secondary ions decreases as the parent mass increases (5). This is a result of the increasing mismatch in parent and target masses and the greater numberof vibrational modes available in the larger molecules, facilitating internal distribution of the deposited energy, rather than dissociation. SID has the potential to increase internal energy deposition and thus to increase the efficiency of MS/MS of high mass ions. Evidence for this is found in Aberth’s recent report of SID of parent ions produced by secondary ion mass spectrometry using a tandem Wien filter instrument (6). A microchannel plate in a grazing incidence configuration was employed as the target and collision energies extended up to 1000 eV. Both positive and negative spectra of leucine-enkephalin (molecular weight 555) were reported, with fragmentation similar to that pro-duced by high-energy CID. Also,(CsI^ Cs* was fragmented to yield (CsI)„Cs+ ions from= 0 to 23. These results show that SID is feasible with high mass ions at collision energies as low as 1 keV.