tailieunhanh - Introduction to Modern Liquid Chromatography, Third Edition part 27

Introduction to Modern Liquid Chromatography, Third Edition part 27. High-performance liquid chromatography (HPLC) is today the leading technique for chemical analysis and related applications, with an ability to separate, analyze, and/or purify virtually any sample. Snyder and Kirkland's Introduction to Modern Liquid Chromatography has long represented the premier reference to HPLC. This Third Edition, with John Dolan as added coauthor, addresses important improvements in columns and equipment, as well as major advances in our understanding of HPLC separation, our ability to solve problems that were troublesome in the past, and the application of HPLC for new kinds of samples. . | 216 THE COLUMN Figure 5-12 High-temperature separation of a pharmaceutical mixture. Sample 1 doxylamine 2 methapyrilene 3 chloropheniramine 4 meclizine 5 triprolidine. Conditions 100 x ZirChrom-PBD column zirconia 20 acetonitrile water with added tétraméthylammonium hydroxide to control pH-13 mL min 140 C 2850psi. Courtesy of ZirChrom Separations Inc. low- and lugh-pH mobilephases 1 pH 13 and they canbe used ntvsry high temperatures 16g g sgows aasparation onazirconiacolumu at pH-13 ande40 selumnipaokidwirapolymsr-aoetcgzsscoeiadispleyed rather poar efficieneg apparagtlyOecause of poor stationary-phase mass transfer. While their performance continues to be improved zirconia columns are still waiting as of the tiny i-ia Uook wae writtee loea rritical appiscatisa wheriiSey perfarm i s etat lhismsyseflec3tiis present limitedimeast oihegh-temperaiuse-eperition l U0 C . For iomeabk rolutis -nd aieeanigibasrdcolumne pnak eheuatogat result regarUlees ulhow dl3yaskinn enuoally wisea liicogia-03led packings are nredemglouizayietolures 3pae-al moOile-phaseedditiaei or fluoriig irerequirei aurgoodoeykeaapuhndreesgnadlinolo3l of N 4 35 . For a ei ffic -ais y ieae 0 eg tee aadieiv0lO3iueiof Neghpeak shape for basic solutesareiimiiyltothaet foiaiS i nssayy t i ai nolignni fnnpH 1 . At the time liii eoakwas uunUsauOlromswha Odorer reit-tewere e t U i S inn the separation sOpaptidee antip stosa- compared oseperntion wtth rlkySsietca columns. Zirceuia-basad roo-oxc4aogool sre iko syrlaHe asae arnon-exchanyarcat bsformed t gs iti uircoma partinierwieh pniylthyleneinrinel followed by a osa-imkmg with l 4-bdlanediordiliycidyierh appronchpno-duces column. dlarare sirb e rom pHreim 3io ned0 eai neu rdao-tpura e organic aiids siorganic anions and highly polar compounds such as sugars. Chemically and thermallystable stronganion-exclrange coiumn-are .