【正文】
s what overloaded plates look like pared to wellspotted plates. The plate on the left has a large yellow smear。 the more samples you plan to run on a plate, the wider it needs to be. Prepare the TLC plate. Shown in the photo to the left is a box of TLC plates, a large uncut TLC sheet, and a small TLC plate which has been cut to a convenient size. Plates will usually be cut and ready for you when you e to lab. Handle the plates carefully so that you do not disturb the coating of adsorbent or get them dirty. Measure cm from the bottom of the plate. Take care not to press so hard with the pencil that you disturb the adsorbent. Using a pencil, draw a line across the plate at the cm mark. This is the origin: the line on which you will spot the plate. It39。 操作以及注意事項 ( 1)嚴格控制點樣位置以及點樣直徑。 DNSCl + AA DNSAA + HCl 反應(yīng)的副產(chǎn)物: DNSNH2黃色熒光和 DNSOH藍色熒光 顯色 DNS氨基酸的雙向?qū)游鰣D譜 Ⅰ Ⅱ 頡 亮 苯 丙 賴 甘 絲 天 脯 谷 DNS-氨基酸的制備 混合 DNS-氨基酸的雙向?qū)游? ( 1)點樣。由于有些 AA結(jié)構(gòu)相似,如只采用一種溶劑系統(tǒng)進行單向?qū)游?,難達到完全分離的目的。 (二)定量分析:可直接在薄板上測定,無須破壞薄層; 用工具將斑點從薄層上取下,用溶劑洗脫,再用其他方法測定。 ?一般所選溶劑要求: → 易與樣品中各組分相分離 溶劑選擇考慮因素 溶劑與吸附劑之間的相互作用力 溶劑與樣品之間的作用因素 ? 溶劑的選擇可通過實驗來確定。 聚酰胺 ——是由于聚酰胺的 C= O(羰基 )及 NH(氨基 )能與被分離物質(zhì)之間形成氫鍵。本身具微酸性,適用于分離酸性及中性物質(zhì)。與所使用的溶劑和樣品中各組分不起化學(xué)反應(yīng); ( 2)應(yīng)具有較大的