Using a Buffer Gas Modifier to Change Separation Selectivity in Ion Mobility Spectrometry.
Using a Buffer Gas Modifier to Change Separation Selectivity in Ion Mobility Spectrometry.
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DOI：
10.1016/j.ijms.2010.08.009
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发表时间：
2010-12-01
影响因子：
1.8
通讯作者：
Hill HH
中科院分区：
文献类型：
--
作者：
Fernández-Maestre R;Wu C;Hill HH
采用电喷雾离子迁移谱-四极杆质谱法（ESI-IMS-QMS）测定了一组常见的α-氨基酸、四种四烷基铵离子、2，4-二甲基吡啶（2，4-lutidine）、2，6-二叔丁基吡啶（DTBP）和缬氨醇在正丁醇存在下的迁移率。在迁移率谱仪中，随着正丁醇浓度的增加，受试化合物的迁移率有不同程度的降低。当2-丁醇的浓度从0.0增加到6.8 mmol m-3时，（2.5×102 ppmv），迁移率降低百分比为：13.6%（丝氨酸）、12.2%（苏氨酸），10.4%（蛋氨酸），10.3%（酪氨酸），9.8%（缬氨醇），9.2%苯丙氨酸，7.8%（色氨酸），5.6%（2，4-二甲基吡啶）、2.2%（DTBP）、1.0% 0%（四甲基铵离子，TMA和四乙基铵离子，TEA）、0.0%（四丙基铵离子，TPA）和0.3%（四丁基铵离子，TBA）。这些变化的流动性取决于大小和空间位阻的离子的电荷，是由于形成大的离子-2-丁醇集群。迁移率的这种选择性变化被施加到分辨率的化合物的混合物具有类似的降低的迁移率，如丝氨酸和缬氨醇，重叠在N2-只有缓冲气体中的IMS光谱。四烷基铵离子和DTBP的相对不敏感性的2-丁醇的引入到缓冲气体中的四个烷基取代基的空间位阻的四烷基铵离子和DTBP中的两个叔丁基基团，这屏蔽了正电荷的离子从2-丁醇分子的附件解释。低缓冲气体温度（100 °C）通过增加离子-2-丁醇相互作用和簇的形成而产生迁移率的最大降低;高温（250 °C）防止簇的形成，并且在将2-丁醇引入缓冲气体中的情况下没有获得离子迁移率的降低。低温和高浓度的2-丁醇在化合物中产生了一系列的离子簇，其中1到3个2-丁醇分子没有空间位阻。还可以看到2个和3个2-丁醇分子的簇。在高浓度的改性剂（6.8 mmol m−3，150°C）下，正离子与2-丁醇分子的配体饱和;当饱和时，当2-丁醇引入缓冲气体时，迁移率不会进一步降低。
The mobilities of a set of common α-amino acids, four tetraalkylammonium ions, 2,4-dimethyl pyridine (2,4-lutidine), 2,6-di-tert-butyl pyridine (DTBP), and valinol were determined using electrospray ionization-ion mobility spectrometry-quadrupole mass spectrometry (ESI-IMS-QMS) while introducing 2-butanol into the buffer gas. The mobilities of the test compounds decreased by varying extents with 2-butanol concentration in the mobility spectrometer. When the concentration of 2-butanol increased from 0.0 to 6.8 mmol m−3 (2.5×102 ppmv), percentage reductions in mobilities were: 13.6% (serine), 12.2% (threonine), 10.4% (methionine), 10.3% (tyrosine), 9.8% (valinol), 9.2% (phenylalanine), 7.8% (tryptophan), 5.6% (2,4-lutidine), 2.2% (DTBP), 1.0% (tetramethylammonium ion, TMA, and tetraethylammonium ion, TEA), 0.0% (tetrapropylammonium ion, TPA), and 0.3% (tetrabutylammonium ion, TBA). These variations in mobility depended on the size and steric hindrance on the charge of the ions, and were due to formation of large ion-2-butanol clusters. This selective variation in mobilities was applied to the resolution of a mixture of compounds with similar reduced mobilities such as serine and valinol, which overlapped in N2-only buffer gas in the IMS spectrum. The relative insensitivity of tetraalkylammonium ions and DTBP to the introduction of 2-butanol into the buffer gas was explained by steric hindrance of the four alkyl substituents in tetraalkylammonium ions and the two tert-butyl groups in DTBP, which shielded the positive charge of the ion from the attachment of 2-butanol molecules. Low buffer gas temperatures (100 °C) produced the largest reductions in mobilities by increasing ion-2-butanol interactions and formation of clusters; high temperatures (250 °C) prevented the formation of clusters, and no reduction in ion mobility was obtained with the introduction of 2-butanol into the buffer gas. Low temperatures and high concentrations of 2-butanol produced a series of ion clusters with one to three 2-butanol molecules in compounds without steric hindrance. Clusters of two and three molecules of 2-butanol were also visible. Ligand-saturation on the positive ions with 2-butanol molecules occurred at high concentrations of modifier (6.8 mmol m−3 at 150°C); when saturated, no further reduction in mobility occurred when 2-butanol was introduced into the buffer gas.
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影响因子：
7.4
作者：
Dwivedi, Prabha;Wu, Ching;Hill, Herbert H., Jr.
通讯作者：
Hill, Herbert H., Jr.
影响因子：
6.2
作者：
EICEMAN, GA;WANG, YF;SHOFF, DB
通讯作者：
SHOFF, DB
影响因子：
7.4
作者：
SUNNER, J;IKONOMOU, MG;KEBARLE, P
通讯作者：
KEBARLE, P
DOI：
10.1039/b915202d
发表时间：
2010-06
期刊：
The Analyst
影响因子：
--
作者：
Fernández-Maestre R;Harden CS;Ewing RG;Crawford CL;Hill HH Jr
通讯作者：
Hill HH Jr
影响因子：
7.4
作者：
EICEMAN, GA;SALAZAR, MR;JAMES, JT
通讯作者：
JAMES, JT