藥物分析新方法與新技術(shù)-液相色譜聯(lián)用技術(shù)及其應(yīng)用-張尊建(參考版)
2025-01-09 08:39本頁面
【正文】 NNNC NN C H3OC H3儀器： Shimadzu LCMS2022A 液相色譜 /質(zhì)譜聯(lián)用 系統(tǒng) 色譜柱： Shimadzu Shimpack VP ODS C18（ 250 mm? mm ID, 5 ?m） 21 ? Nuclear magic resonance (NMR) spectroscopy is the most powerful technique for the structural elucidation of unknown pounds. ? This is the reason why the hyphenation between chromatographic seperation technique together with NMR spectroscopy is being increasingly popular. ? Both LC(1899) and NMR(~1945) have been and still routinely used in mixture analysis. 第三部分 液核（ LC/NMR）聯(lián)用技術(shù) Background of instruments development 22 ? The first online LCNMR experiments were performed in the late 1970s by Watanabe and Niki who demonstrated stoppedflow measurements of a mixture of known pounds. ? A successful and practical LCNMR coupling has been achieved only in the last decade. ? Currently, there are several LCNMR systems available, and data acquisition can be achieved using various modes depending on the status of the sample during measurement. 23 Coupling technology of LCNMR ? Onflow LCNMR ? LCNMR under static conditions： ? Direct stopflow ? Loop storage/loop transfer ? LCSPENMR ? LCNMRMS ? Cryogenic technology in LCNMR 24 Onflow LCNMR(continuous flow) ? Here,the outlet of the chromatographic system is connected to an NMR detection cell. The NMR spectra are acquired continuously while the sample is flowing through the detection cell. ? The chromatography and NMR systems perform pletely independent by of each other. The only necessary link is the liquid connection between the column and the NMR detection cell. ? The NMR spectrometer can act as a detector in the chromatographic system, so that even a conventional LC detector in the chromatographic system is not necessary. 25 LCNMR under static conditions－ Direct stopflo
教學(xué)課件相關(guān)推薦
鄂ICP備17016276號(hào)-1