Baseline correction of absorption-mode Fourier transform ion cyclotron resonance mass spectra
Baseline correction of absorption-mode Fourier transform ion cyclotron resonance mass spectra
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DOI：
10.1016/j.ijms.2012.06.007
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发表时间：
2012-07-01
影响因子：
1.8
通讯作者：
Marshall, Alan G.
中科院分区：
文献类型：
--
作者：
Xian, Feng;Corilo, Yuri E.;Marshall, Alan G.
吸收模式傅里叶变换离子回旋共振(FT-ICR)质谱图显示出两种基线失真：一种是即使在没有信号峰的情况下也有缓慢的周期振荡，另一种是在信号峰附近与信号幅度成正比的附加失真。除非基线系统变化比基线均方根随机噪声小得多，否则这些失真会干扰自动拾峰。我们先前已经证明，慢振荡可以通过低通滤波来消除。在这里，我们提出了一种快速、稳健和自动化的算法，使吸收模式光谱基线变平，即使在信号峰值附近也是如此。该方法首先定义基线数据值，然后进行线性内插以在所定义的值之间生成基线数据值，然后进行Boxcar平滑以生成最终的基线光谱，最后从原始光谱中减去该基线以产生基线平坦的吸收模式光谱。我们将该算法应用于原油光谱(有8000个峰)和核糖核酸酶A蛋白质光谱(具有多电荷离子同位素分布)。我们在不损失质量精度的情况下识别了更多的峰(原油)，并获得了更准确的同位素分布(RNaseA)。(C)2012爱思唯尔B.V.保留所有权利。
An absorption-mode Fourier transform ion cyclotron resonance (FT-ICR) mass spectrum exhibits two types of baseline distortion: a slow periodic oscillation even where no signal peaks are present, and additional distortion near signal peaks and proportional to signal magnitude. These distortions interfere with automated peak-picking, unless the baseline systematic variation is much less than baseline rms random noise. We previously showed that the slow oscillation is removed by low-pass filtering. Here, we present a fast, robust, and automated algorithm that flattens the absorption-mode spectral baseline, even in the vicinity of signal peaks. The method begins by defining baseline data values, followed by linear interpolation to generate baseline data values between the defined values, then boxcar smoothing to generate a final baseline spectrum, and final subtraction of that baseline from the original spectrum to yield a baseline-flattened absorption-mode spectrum. We apply the algorithm to a crude oil spectrum (with 8000 peaks) and to a ribonuclease A protein spectrum (with multiply-charged ion isotopic distributions). We identify many more peaks (crude oil) without loss of mass accuracy, and obtain more accurate isotopic distributions (RNase A). (C) 2012 Elsevier B.V. All rights reserved.