School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK.
Lab Chip. 2018 Sep 26;18(19):3018-3024. doi: 10.1039/c8lc00712h.
A generic approach is presented that allows high-resolution NMR spectroscopy of water/oil droplet emulsions in microfluidic devices. Microfluidic NMR spectroscopy has recently made significant advances due to the design of micro-detector systems and their successful integration with microfluidic devices. Obtaining NMR spectra of droplet suspensions, however, is complicated by the inevitable differences in magnetic susceptibility between the chip material, the continuous phase, and the droplet phases. This leads to broadening of the NMR resonance lines and results in loss of spectral resolution. We have mitigated the susceptibility difference between the continuous (oil) phase and the chip material by incorporating appropriately designed air-filled structures into the chip. The susceptibilities of the continuous and droplet (aqueous) phases have been matched by doping the droplet phase with a Eu3+ complex. Our results demonstrate that this leads to a proton line width in the droplet phase of about 3 Hz, enabling high-resolution NMR techniques.
本文提出了一种通用的方法，可用于对微流控装置中的水/油液滴乳液进行高分辨率 NMR 光谱分析。由于微检测器系统的设计及其与微流控装置的成功集成，微流控 NMR 光谱学最近取得了重大进展。然而，由于芯片材料、连续相和液滴相之间不可避免的磁化率差异，获得液滴悬浮液的 NMR 光谱变得复杂。这导致 NMR 共振线变宽，并导致光谱分辨率降低。我们通过在芯片中加入设计适当的充空气结构，减轻了连续相（油相）和芯片材料之间的磁化率差异。通过在液滴相中掺杂 Eu3+配合物，使连续相和液滴（水相）的磁化率相匹配。我们的结果表明，这导致液滴相中质子线宽约为 3 Hz，从而实现了高分辨率 NMR 技术。
