Development of Green Chemistry-oriented Analytical Method for Environmental and Waste Samples by Nano/Micro LC/MS

微型液相色谱/质谱联用技术（LC/MS）可以节约溶剂，减少浪费，为绿色化学做出贡献。然而，微型LC/MS对于测量高度疏水的化合物，特别是小分子化合物，大多是无效的。我们开发了一种微型LC/MS方法，用于测量疏水性和小分子量的环境化合物。该方法包括微液相色谱中的溶质聚焦技术和质谱中的激发氩离子化方法，通过在分析微柱上游的微混合器中用亲水溶液动态稀释疏水溶液，成功地实现了高疏水性化合物的溶质聚焦。对于醛同系物的O-（4-氰基-2-乙氧基苄基）羟胺（CNET）衍生物的丙酮溶液，当进样5 μ L 0.2 - 10 ppb溶液时，峰的理论塔板数范围为27，000 - 60，000。这些化合物的工作曲线大多呈线性，回归良好，某些疏水性化合物的氩离子化效果较好。它能从丁酮中产生高信噪比（s/n）的M ~+离子，其电离能（I.E.）质子亲合能分别为9.52eV和827.3kJ/mol。甲基吡啶产生的M+离子和MH+离子（即：9.26eV，PA：949.1kJ/mol）的S/N值分别是常压化学电离法（APCI）的8倍和30倍，为环境和废物分析中有机溶剂的节约和减少提供了一条新的途径，为绿色化学的发展做出了贡献

Micro liquid chromatography/mass spectrometry (LC/MS) can contribute green chemistry by saving solvent and reducing waste. However micro LC/MS was mostly ineffective for measuring highly hydrophobic compounds, in particular for small molecules. We developed a micro LC/MS method for measuring hydrophobic and small molecular mass compounds of environmental interest. The method includes solute focusing technique in micro LC and an ionization method by excited argon for mass spectrometry.Solute focusing was successfully performed for highly hydrophobic compounds by dynamically diluting hydrophobic solution with hydrophilic solution in micro mixer upstream of analytical micro column. In case of O-(4-cyano-2-ethoxybenzyl) hydroxylamine (CNET) derivatives of aldehyde homologues in acetone, theoretical plate numbers of the peaks were ranged 27, 000to 60, 000 when 5uL of the solution in 0.2to 10ppb were injected. Working curves of those compounds were mostly linear with good regression.Ionization by excited argon was efficient for some hydrophobic compounds. It generated M+'ion with high signal to noise ratio (s/n) from butanone, of which the ionization energy (I.E.) and the proton affinity (PA) are 9.52eV and 827.3kJ/mol, respectively. M+'ion and MH+ ion generated from picoline (I.E.: 9.26eV, PA: 949.1kJ/mol) were respectively 8 and 30 times higher in s/n than those from Atmospheric Pressure Chemical Ionization(APCI).Through this study, a way to save and reduce organic solvents, which contribute green chemistry in environmental and waste analysis, was developed