Helmholtz Zentrum München, German Research Center for Environmental Health, Research Unit Analytical Biogeochemistry (BGC), Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany.
Helmholtz Zentrum München, German Research Center for Environmental Health, Research Unit Analytical Biogeochemistry (BGC), Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany; Chair of Analytical Food Chemistry, Technische Universität München, 85354 Freising, Germany.
Water Res. 2017 Jun 1;116:316-323. doi: 10.1016/j.watres.2017.03.038. Epub 2017 Mar 19.
Solid phase extraction (SPE) has become a widespread method for isolating dissolved organic matter (DOM) of diverse origin such as fresh and marine waters. This study investigated the DOM extraction selectivity of 24 commercially available SPE sorbents under identical conditions (pH = 2, methanol elution) on the example of Suwannee River (SR) water and North Sea (NS) water by using DOC analysis and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Proton nuclear magnetic resonance (H NMR) spectroscopy was employed to assess leaching behavior, and HLB sorbent was found to leach substantially, among others. Variable DOC recoveries observed for SR DOM and NS DOM were primarily caused by the respective molecular composition, with subordinated and heterogeneous contributions of relative salinity. Scatter of average H/C and O/C elemental ratios and gross alignment in mass-edited H/C ratios according to five established coarse SPE characteristics was near identical for SR DOM and NS DOM. FTMS-based principal component analysis (PCA) provided essentially analogous alignment of SR DOM and NS DOM molecular compositions according to the five established groups of SPE classification, and corroborated the sorption-mechanism-based selectivity of DOM extraction in both cases. Evaluation of structural blanks and leaching of SPE cartridges requires NMR spectroscopy because FT-ICR mass spectrometry alone will not reveal inconspicuous displacements of continual bulk signatures caused by leaching of SPE resin constituents.
固相萃取（SPE）已成为一种广泛应用的方法，用于分离不同来源的溶解有机物（DOM），如淡水和海水。本研究通过使用 DOC 分析和傅里叶变换离子回旋共振质谱（FT-ICR MS），以苏万尼河（SR）水和北海（NS）水为例，在相同条件（pH = 2，甲醇洗脱）下，研究了 24 种市售 SPE 吸附剂对 DOM 萃取选择性。质子核磁共振（H NMR）光谱用于评估浸出行为，发现 HLB 吸附剂大量浸出，等等。观察到的 SR DOM 和 NS DOM 的可变 DOC 回收率主要是由于各自的分子组成造成的，而相对盐度的次要和异质贡献。根据五个已建立的粗 SPE 特征，SR DOM 和 NS DOM 的平均 H/C 和 O/C 元素比的散点和质量编辑的 H/C 比的大体对齐几乎相同。基于 FTMS 的主成分分析（PCA）根据五个已建立的 SPE 分类组，对 SR DOM 和 NS DOM 的分子组成进行了基本相同的对齐，并证实了两种情况下 DOM 萃取的基于吸附机理的选择性。由于仅 FT-ICR 质谱无法揭示由 SPE 树脂成分浸出引起的连续体信号的不明显位移，因此需要 NMR 光谱来评估结构空白和 SPE 小柱的浸出。
