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

微液相色谱/质谱仪(LC/MS)可以节省溶剂和减少废物，从而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。我们建立了一种微型LC/MS方法，用于测定具有环境意义的疏水性和小分子化合物。该方法包括微LC中的溶质聚焦技术和激发Ar电离法，通过在分析微柱上游的微型混合器中动态稀释疏水溶液和亲水溶液，成功地实现了对高度疏水化合物的溶质聚焦。以丙酮中醛同系物的O-(4-氰基-2-乙氧基苄基)羟胺(CNET)衍生物为例，当进样量为0.2~10 ppb时，峰的理论板数为27,000~60,000。这些化合物的工作曲线大部分都是线性的，回归良好，对于某些疏水化合物来说，激发Ar电离是有效的。由丁酮产生高信噪比的M~+‘离子(S/n)，其电离能和质子亲和能分别为9.52 eV和827.3kJ/m o l，而由甲基吡啶产生的M~+’离子和MH+离子分别是常压化学电离产生的M~+‘离子和MH~+离子的8倍和30倍，为绿色化学在环境和废物分析中的应用奠定了基础

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