Development of efficient pretreatment method for analyzing polar compound using solid-phase derivatization

考察了五氟吡啶固相衍生苯酚的两种固相：(1)强阴离子交换固相通过碱性溶液通过两种强阴离子交换固相，即硅基固相和聚合物基固相(Waters，OASIS MAX)。由于二氧化硅基固相对碱性溶液不稳定，酚类离子不能完全吸附在固相上。另一方面，聚合物基固相对酚类离子有较好的吸附作用。将五氟吡啶的正己烷溶液保留在色谱柱上10分钟，即可实现定量衍生化。我们发现疏水相互作用和离子相互作用对吸附起重要作用。为了评价基质的效果，在中性和阴离子化合物存在的情况下进行了固相衍生化。因此，衍生化反应完全不受影响。中性化合物w…更多的是通过让丙酮通过色谱盒来去除，阴离子化合物(羧酸)在色谱盒中保持不反应。该方法的检出限(100ml样品中检出限为0.88~8.5 ng/L)远好于相转移试剂双相体系(50ml样品中检出限为6.9~85 ng/L，J·C_(984)(2003)237~243)。对河水样品的回收率达到令人满意的水平。(2)离子对固相萃取吸附THA(四己基溴化铵)的结果与OASIS MAX类似。在这种情况下，有效地吸附在C&lt；18&gt；固相+THA上的酚类离子被洗脱，并用五氟吡啶的丙酮溶液进行衍生化。这种离子对固相萃取不需要反应时间。较少

Two types of solid phases were examined for solid-phase derivatization of phenols with pentafluoropyridine.(1) Strong anion-exchange solid phaseAdsorption of phenols was performed by passing an alkaline solution through two strong anion-exchange solid phases, silica-based solid and polymer-based solid (Waters, OASIS MAX). Since the silica-based solid phase was labile to the alkaline solution, phenolate ions were not entirely adsorbed onto the solid phase. On the other hand, polymer based solid phase adsorbed effectively the phenolate ions. Quantitative derivatization was attained by retaining hexane solution of pentafluoropyridine to the cartridge for 10 minutes. We found that hydrophobic interaction as well as ionic interaction plays an important role for the adsorption.To evaluate the effect of matrix, the solid-phase derivatization was carried out in the presence of neutral and anionic compounds. As a result, derivatization reaction was not influenced at all. The neutral compounds w … More ere removed by passing acetone through the cartridge and anionic compounds (carboxylic acid) remained unreacted in the cartridge. Only the phenols derivatized with pentafluoropyridine were eluted with hexane solution of pentafluoropyridine.The limit of detection of this method (LOD : 0.88-8.5 ng/l in 100 ml sample) is much better than that of biphasic system using phase-transfer reagent (LOD : 6.9-85 ng/l in 50 ml sample, J.Chromatography A 984 (2003) 237-243), indicating the high performance of this method. Recovery from river water sample was satisfactory level. The method was successfully applied to the environmental water.(2) Ion-pair solid-phase extraction using C_<18>C_<18> solid phase on which THA (tetrahexylammonium bromide) was adsorbed, gave the similar results to OASIS MAX described above. In this case, pheolate ions that were effectively adsorbed onto C_<18> solid phase + THA, were eluted and derivatized with acetone solution of pentafluoropyridine. No reaction time was required for this ion-pair SPE. Less