Robust NMR water signal suppression for demanding analytical applications

We describe the design and application of robust, general-purpose water signal suppression pulse sequences well suited to chemometric work. Such pulse sequences need to deal well with pulse mis-calibrations, radiation damping, chemical exchange, and the presence of sample inhomogeneities, as well as with significant variations in sample characteristics such as pH, ionic strength, relaxation characteristics and molecular weight. Of course, such pulse sequences should produce un- distorted lineshapes and baselines and work well both under automation and in the hands of non-experts. As an example, one such pulse sequences, Robust-5, will be presented. This new pulse sequence meets those criteria and is able to reduce a 50 M proteo water signal down to a 0.9 mM level, without fiine tuning, and under automation, and it is therefore well suited to the most demanding of analytical applications.本文阐述了适配化学计量学（chemometrics）工作的稳健型通用水信号抑制脉冲序列（pulse sequences）的设计与应用。此类脉冲序列需能够妥善应对脉冲失校准、辐射阻尼（radiation damping）、化学交换以及样品不均匀性等问题，同时需适配pH值、离子强度、弛豫特性与分子量等样品参数的显著波动。此外，此类脉冲序列应生成无畸变的谱线线形与基线，且可在自动化操作环境及非专业操作人员手中均实现稳定运行。作为示例，本文将介绍一款名为Robust-5的脉冲序列。这款全新的脉冲序列符合前述全部标准，可在无需精细调谐且自动化运行的条件下，将50摩尔浓度的蛋白质结合水信号抑制至0.9毫摩尔浓度水平，因此极为适配严苛的分析应用场景。