Reversible reductions of oxazine dyes induced by primary particle bombardment in liquid secondary-ion mass spectrometry.
Reversible reductions of oxazine dyes induced by primary particle bombardment in liquid secondary-ion mass spectrometry.
复制标题
液体二次离子质谱中初级粒子轰击引起的恶嗪染料的可逆还原。
DOI：
10.1002/rcm.1290021112
复制
发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Busch,KL
中科院分区：
文献类型：
--
作者：
Brown,SM;Busch,KL
在液体二次离子质谱仪(SIMS)和快原子轰击质谱仪(FAB)中测得的质谱图通常含有由中性样品分子形成的[M+HJF]等强离子。对于弱酸性的液体基质，如甘油，添加的质子被认为来自基质和样品分子之间的质子化反应。此外，还观察到在未辐射的液体基质中发生了许多其他反应，包括脱卤化、甲基化反应，以及更常见的还原反应。减税？对于各种有机染料、多肽、核苷和基于苯醌的化合物，已观察到以氢加到样品中形成[M+2H]+和[M+3H]+为特征的各种还原机理。Ligon3和Gale4提出，还原涉及自由基物种(通过高能粒子轰击在基质中形成)与中性样品分子的反应。Wirth‘曾提出，偶氮多肽的减少是由于马鞍场放电FAB源发出的短波紫外线和X射线辐射。Pelzer6提出有机染料在液体基质中发生氧化/还原反应，还原的难易程度与电化学还原的难易程度有关？这与轰击现场形成的小型电化学池类似。Pelzer等人还确定了还原的[Fe(II)(Acac)Gf+]与[Fe(III)(Acac)，]+(acac是乙酰丙酮配体)的比值受初级离子电流的影响。虽然还原反应的产物很容易形成，但要阐明其机理是困难的。当分子本身具有光化学反应或电化学反应时，在没有液体基质的情况下可能会发生还原，如图所示
Mass spectra measured in liquid secondary-ion mass spectrometry (SIMS) and fast-atom bombardment (FAB) mass spectrometry typically contain intense ions such as [M+ HJf formed from neutral sample molecules. For a slightly acidic liquid matrix such as glycerol, the added proton is thought to be derived from a protonation reaction between the matrix and sample molecule. In addition, many other reactions have been observed to occur in the unradiated liquid matrices including dehalogenations,’methyiation reactions,’and more commonly, reductions. Reductions? typified by the addition of hydrogen to the sample to form, for instance,[M+ 2H]+ and [M+ 3H]+, have been observed for various organic dyes, peptides, nucleosides, and quinone-basedVarious mechanisms for these reductions have been proposed. Ligon3 and Gale4 have proposed that the reductions involve reactions of radical species (formed in the matrix by the energetic particle bombardment) with neutral sample molecules. Wirth’has suggested that reduction of azo-containing peptides is due to short-wave UV and x-ray radiation emanating from a saddle-fieid discharge FAB source. Pelzer6 proposed that organic dyes undergo oxidation/reduction reactions in the liquid matrix, and that the ease of reduction is related to the ease of electrochemical reduction? suggesting the analogy of a small electrochemical cell formed at the site of bombardment. Pelzer et aL7 have also determined that the ratio of reduced [Fe (II)(acac) Gf+ to [Fe (III)(acac),]+(acac is the acetylacetonate ligand) is influenced by the primary ion current. Although the products of the reduction reaction are easily formulated, the elucidation of the mechanism is difficult. When the molecules themselves are photo-or electrochemically reactive, reductions may occur in the absence of the liquid matrix, as shown
登录
查看更多内容
影响因子：
7.4
作者：
Sethi,SK;Nelson,CC;McCloskey,JA
通讯作者：
McCloskey,JA
了解与二次离子质谱实验相关的甘油表面：综述
DOI：
10.1016/0168-1176(87)87044-1
发表时间：
1987
期刊：
International Journal of Mass Spectrometry and Ion Processes
影响因子：
--
作者：
W. Ligon;S. Dorn
通讯作者：
S. Dorn
二次离子质谱法和甘油溶液的快原子轰击中发生的氧化还原过程
DOI：
--
发表时间：
1984
期刊：
影响因子：
--
作者：
G. Pelzer;E. Pauw;D. Dung;J. Marien
通讯作者：
J. Marien
影响因子：
2.3
作者：
D. J. Burinsky;Robert L. Dilliplane;G. Didonato;K. Busch
通讯作者：
K. Busch
DOI：
10.1016/0168-1176(86)85001-7
发表时间：
1986
期刊：
International Journal of Mass Spectrometry and Ion Processes
影响因子：
--
作者：
K. Duffin;K. Busch
通讯作者：
K. Busch