色層分析法之原理與應(yīng)用-wenkub
2022-08-18 09:16:03 本頁(yè)面
【正文】 (GLC) Wall Coated Open Tubular (WCOT) Liquid Phase Capillary Columns (90% Of Applications) Like dissolves like or Polar interacts with polar Separation by partitioning or differential solubility in stationary phase Components are separated based on differences in polarity (interaction of dipole forces) Generally Example: Alcohols are polar Carbowax is polar liquid phase Gas Liquid Chromatography (GLC) Parameter effect on R down sides Column length the longer the better longer elution time Film thickness the thinner the better smaller sample loads poor retention for extremely volatile pounds Inner diameter the smaller the better smaller sample loads Summary of column parameters on Resolution 不同型式管柱性能之比較 Comparison of Column Types 12456891011amp。RRBASABBBttRWWkNk??????????????? ??????? ???增加理論板數(shù) (N)：即增加管柱長(zhǎng)度或減小理論板高． ?增加選擇因子 (分離因子 ) α (α1)/ α 0 改變固定相，柱溫 (GC)，流動(dòng)相 (HPLC) ?改變?nèi)萘恳蜃樱? k’ 30 50 k’/(1+ k’) 影響層析峰寬之因素 ? 渦流擴(kuò)散 (eddy diffusion) ? 縱向擴(kuò)散 (longitudinal diffusion) ? 非平衡質(zhì)量傳送 (nonequilibrium mass transfer) 控制因子：流動(dòng)速率、填充物粒徑、擴(kuò)散速率、固定相厚度 van Deemter equation 導(dǎo)出流動(dòng)相流動(dòng)速率ｕ與Ｈ之關(guān)係式 H = A + B/u + Cu ? A：渦流擴(kuò)散項(xiàng) (多徑項(xiàng) )，由粒徑 、 幾何形狀及固定相填充緊密度有關(guān) A=2λdp ? B：縱向擴(kuò)散項(xiàng) (分子擴(kuò)散 ) ? C：質(zhì)傳阻力項(xiàng) Partition Packing Packed Columns Carrier Gas Liquid Phase Solid Support Very porous wit
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