烷基-二醇基硅胶填料的合成及对莠去净类除草剂的在线分离

三步合成了烷基-二醇基硅胶(ADS)色谱材料，首先用γ-缩水甘油醚氧丙基三甲氧基硅烷把功能基团键合到硅胶基体上，再把该环氧化硅胶与硬脂酸反应以制备酯型十八烷基反相填料，最后在20MPa压力下装成色谱预柱(35×4.6mm I.D)。用该预柱通过六通阀后接ODS分析柱(250×4.6mm I.D)，构成中心切割二维HPLC。该系统能对具有一定疏水性的化合物进行在线富集，实现环境及生物复杂样品直接进样分离分析。使用该系统对尿中的莠去净和西玛津残留进行了分离分析，以含有0.1%乙酸的酸性水缓冲液对加标尿液中莠去净类化合物保留在预柱上，干扰分析的大分子被排阻而无保留通过，其它干扰分子保留小而通过，再切换六通阀，以乙腈和0.1%乙酸水溶液进行梯度洗脱，进而在下一级ODS分析柱上进行分离（紫外检测225nm），两种除草剂的分离分析取得了良好的定性定量结果

Synthesis of a Alkyl-diol Silica and Application as Pre-column in Coupled-column High-Performance Liquid Chromatography for Atrazines

A alkyl-diol silica was synthesized by three steps：first，γ-Chloropropylsilane-substituting of silica, then esterifying of γ-Chloropropylsilane-substituted silica and last digesting of ester by lipase. Under 20MPa pressure, pre-column were packed with the material(35×4.6mm I.D). Efficient on-line clean-up and concentration atrazine and simazine was studied by the pre-column as the first column and an ODS column (250mm×4.6mm I.D) as the second column ( analytical column). Sample matrix are discharged by the pre-column. The mobile phases applied consisted of 0.1% HOAc (pH3.0) acetonitrile-water on extraction column with UV detection at 225nm. Then, coupled-column liquid chromatographic methods for the direct analysis of atrazine and simazine in urine was established. As a result, the system showed good chromatographic property in the on-line analysis of atrazine and simazine in urine.