DataSheet1_Introducing Nafion for In Situ Desalting and Biofluid Profiling in Spray Mass Spectrometry.docx

We introduce Nafion into the ambient ionization technique of spray mass spectrometry to serve for in situ desalting and direct analysis of biological fluids. Nafion was coated onto the surface of the triangular spray tip as the cation exchange material. Because the sulfonic group from the Nafion membrane effectively exchanges their carried protons with inorganic salt ions (e.g., Na+ and K+), the analyte’s ionization efficiency can be significantly enhanced by reducing ion suppression. The desalting efficiency can reach 90% and the maximum tolerance of the absolute salt amount reaches 100 μmol. The mass spectral profile can also be simplified by removing the multiple adducted ion types from small-molecule drugs and metabolites ([M + Na]+ and [M + K]+), or multiply charged ions formed by proteins ([M + nNa]n+ and [M + nK]n+). Thus, the Nafion coating makes less ambiguous data interpretation collected from spray mass spectrometry for qualitative profiling or quantitative measurement of a target analyte.

本研究将Nafion材料引入到喷雾质谱法的环境电离技术中，旨在实现生物流体中的原位脱盐及直接分析。Nafion材料被涂覆于三角喷嘴表面，作为阳离子交换材料。由于Nafion膜中的磺酸基团能够有效地将其携带的质子与无机盐离子（如Na+和K+）进行交换，通过减少离子抑制效应，可显著提升分析物的电离效率。脱盐效率可达90%，对绝对盐量的最大容忍度达到100 μmol。此外，通过去除小分子药物和代谢物（[M + Na]+和[M + K]+）的多种加合离子类型，或蛋白质形成的多重电荷离子（[M + nNa]n+和[M + nK]n+），还能简化质谱分析谱图。因此，Nafion涂覆技术使得从喷雾质谱法收集的数据在定性分析或定量测量目标分析物时，具有更明确的解释性。