The ⁷⁷Se NMR spectra of selenate were studied under various circumstances, such as concentration, pH, temperature, ionic strength, and D₂O:H₂O ratio, in order to examine its potential as a water-soluble internal chemical shift standard. The performance of selenate as a chemical shift reference and that of other attempted ones from the literature (dimethyl selenide, tetramethylsilane/TMS, and 3-(trimethylsilyl)propane-1-sulfonate/DSS) was also explored. The uncertainty in the resulting chemical shift relative to the effective spectral width is comparable to that of DSS. Compared to the currently prevalent water-soluble external chemical shift reference, selenic acid solution, the properties of internal selenate are much more favorable in terms of ease of use. We have also demonstrated that selenate can be used in reducing media, which is inevitable for the analysis of selenol compounds. Thus, it can be stated that sodium selenate is a robust internal chemical shift reference in aqueous media for ⁷⁷Se NMR measurements; the chemical shift of this reference in a solution containing 5 V/V% D₂O at 25°C and 0.15 mol·dm⁻³ ionic strength is 1048.65 ppm relative to 60 V/V% dimethyl selenide in CDCl₃ and 1046.40 ppm relative to the ¹H signal of 0.03 V/V% TMS in CDCl₃. In summary, a water-soluble, selenium-containing internal chemical shift reference compound was introduced for ⁷⁷Se NMR measurements for the first time in the literature, and with the aforementioned results all previous ⁷⁷Se measurements can be converted to a unified scale defined by the International Union of Pure and Applied Chemistry.

中文翻译：

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硒酸盐 - 77Se 水相 NMR 光谱的内部化学位移标准

研究了不同条件下硒酸盐的⁷⁷ Se NMR 谱，例如浓度、pH、温度、离子强度和 D ₂ O:H ₂O 比，以检查其作为水溶性内部化学位移标准的潜力。还探讨了硒酸盐作为化学位移参考的性能以及文献中其他尝试的性能（二甲基硒化物、四甲基硅烷/TMS 和 3-（三甲基甲硅烷基）丙烷-1-磺酸盐/DSS）。由此产生的化学位移相对于有效光谱宽度的不确定性与 DSS 相当。与目前流行的水溶性外部化学位移参比硒酸溶液相比，内部硒酸盐的性质在易用性方面更加有利。我们还证明了硒酸盐可用于还原介质，这对于分析硒醇化合物是不可避免的。因此，⁷⁷ Se NMR 测量；在含有5的溶液该参考文献的化学位移 V / V％d ₂ ö在25℃和0.15摩尔·分米^-3的离子强度是1048.65相对ppm至60  V / V二硒化物在CDCl％₃和1046.40 ppm的相对CDCl ₃中 0.03 V / V % TMS的¹ H 信号 。总之，在文献中首次引入了一种水溶性的、含硒的内部化学位移参考化合物，用于⁷⁷ Se NMR 测量，并且上述结果所有以前的⁷⁷Se 测量值可以转换为国际纯粹与应用化学联盟定义的统一尺度。