Evaluation of protocols for reproducible electrospray in-source collisionally induced dissociation on various liquid chromatography/mass spectrometry instruments and the development of spectral libraries
Evaluation of protocols for reproducible electrospray in-source collisionally induced dissociation on various liquid chromatography/mass spectrometry instruments and the development of spectral libraries
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DOI：
10.1002/rcm.843
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发表时间：
2002-01-01
影响因子：
2
通讯作者：
Conway, B
中科院分区：
文献类型：
--
作者：
Bristow, AWT;Nichols, WF;Conway, B
质谱库为利用分子量和裂解信息鉴定未知化合物提供了一种工具。具有电喷雾电离(ESI)和大气化学电离(APCI)源的质谱仪能够使用源内碰撞诱导解离(CID)产生这种类型的数据，并且可以创建源内CID库。由于不同仪器制造商的电喷源设计各不相同，生产可在所有仪器类型的库中使用的可重复的源内CID谱并不是一项简单的任务。到目前为止，对源代码内CID库生产的评估往往集中在一个制造商的类似仪器上。这些研究也倾向于集中在特定的化合物类别上，分子量范围有限。这份报告描述了在来自四个不同制造商的六台仪器上使用ESI源内CID创建质谱库的协议的调查结果。总体目标是创建一个用于识别未知数的光谱库。然后，该库可以应用于所有制造商的电喷雾仪器。我们尝试了两种不同的实验方案。第一个使用调谐化合物来建立标准的ESI源条件，具有固定的碎裂电位。第二种是[M+H](+)离子在一定程度上的衰减。测试了一系列不同的化合物(药物、照相、农药)，以确定六种仪器上光谱的重复性。这两种方案在各种仪器上产生的光谱在许多情况下是非常相似的。在其他例子中，光谱不仅在相对离子丰度上不同，而且在光谱含量方面也不同。还报告了有关离子源设计影响的重要观察结果。通过比较每个仪器上每个光谱中最丰富的五个离子(匹配的每个离子的20%)，离线计算光谱的重现性程度。之所以采用这种方法，是因为我们没有一个软件包来满足我们的光谱比较要求。匹配因子(%Fit)是通过将每个光谱与每个仪器上记录的相同化合物的光谱以及所有其他化合物的光谱进行比较来计算的。通过离线方法得到的%Fit值清楚地显示了不同仪器之间的光谱重现性，也区分了各种化合物的光谱。这种方法的适用性是通过盲法试验进行测试的，其中几种化合物被作为未知数提出，它们的源内CID光谱被记录下来，并使用五离子方法进行鉴定。版权所有(C)2002 John Wiley Sons，Ltd.
Mass spectral libraries provide a tool for identifying unknown compounds using both molecular weight and fragmentation information. Mass spectrometers with electrospray ionisation (ESI) and atmospheric chemical ionisation (ApCI) sources have the capability to produce data of this type using in-source collisionally induced dissociation (CID), and in-source CID libraries can be created. Due to the variation in electrospray source design from different instrument manufacturers, the Production of reproducible in-source CID spectra that can be used in libraries for all instrument types is not a trivial task. To date, the evaluation of the production of in-source CID libraries has tended to focus on similar instruments from one manufacturer. The studies have also tended to focus on specific compound classes, with a limited molecular weight range.This report describes the findings from the investigation of protocols for the creation of mass spectral libraries using ESI in-source CID on six instruments from four different manufacturers. The overall goal,was to create a spectral library for the identification of unknowns. The library could then be applied across all manufacturers' electrospray instruments.Two different experimental protocols were attempted. The first used a tuning compound to establish standard ESI source conditions, with fixed fragmentation potentials. The second involved the attenuation of the [M + H](+) ion to a known degree. A diverse range of compounds (pharmaceutical, photographic, pesticides) was tested to establish the reproducibility of the spectra on the six instruments. Both protocols produced spectra on the various instruments that in many cases were very similar. In other examples, the spectra differed not only in their relative ion abundances, but also in terms of the spectral content. Important observations regarding the effect of ion source design are also reported.The degree of spectral reproducibility was calculated off-line by comparing the five most abundant ions (20% for each ion that matches) from each spectrum on each instrument. This approach was adopted, as we do not possess a soft-ware package that met our requirements for spectral comparison. Match factors (% fit) were calculated by comparing each spectrum against the spectra recorded for the same compound and then for all other compounds, on each instrument. The % fit values derived by the off-line approach gave a clear view of the spectral reproducibility from instrument to instrument and also discriminated the spectra of the various compounds from each other. The applicability of this approach was tested using a blind trial in which several compounds were presented as unknowns, their in-source CID spectra recorded and the five-ion approach used for identification. Copyright (C) 2002 John Wiley Sons, Ltd.