tailieunhanh - Introduction to Modern Liquid Chromatography, Third Edition part 74

Introduction to Modern Liquid Chromatography, Third Edition part 74. 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. . | 686 ENANTIOMER SEPARATIONS NMR study confirmed that 2-propanol displaces hexane more efficiently from the polymeric selector forming more ordered solvent-CSP complexes 54 . If the mobile phase is changed sufficient equilibration time should be allowed to ensure the complete removal of the polar solvent. In order to achieve reproducible results when switching from an additive-free to an additive-containing mobile phase . trifluoroaceticacidordiethylamine and viceversa a prolongedequilibration time may Oe aeduirrdi55L In rcrecaser deu usr oiphrtecular odditiver mayirirdur iranhent or even persistent cunfarmatiunei changes he thepolameoic sirdctureofauoiyiencdnridn derivative eitneeeohanciugdr f ttonnitrO iaitfi i t oitiuiii h i t f irn. Peesiraunt changes in selectivitywore demonstratedtooccur with amyiore-basnC n istfttv operation whir NP-iupumcUtle phases that include diethylamine 56 however flushing with 2-pnopauoiwus shownuo eestoro ti rio l ais i is i -ty. AcCdiroa-mrnt of ChiralpnkADuH addChirakeiODiHUCPs aist chongadthdr prvfovmanee- which was largetyroatooud bywatUinuwich cimnu-aodtoCiudg moOrlrphares. u tt iT es in enantiose-tccivito may r iro oeuur durto camneratdre-icdeced ccnfoemadional changes otnurf trh OTSi Althovs rrn i rny c trd dr the NT-mode a s í ccdcJrC t í Ser ís hara brrn demonstratedlo poasebs mudnmodalamplicability. BedrSd 1-6 1 cndd-e already medtioncC atf cmodei5aS t-iaee eclumns acnby d id mthe 0 -00- mode POmt df . ThePO modeutidzet donaqtieoutmodiOr ghvses that ure raoUe up of polae ncuerne 1 008 011 as methanol or acetonitrile or a mixture of both to whichsmaii cmormfs of organic ecidslaeeticaoid foneac add Bnd base triethyiaminr Uiethylomiue Ammonia ar-odO-i bu ti o1tita Bildt t eompetingagents. dm imdortanBiAnefit ePthe POmodv ctnponsaU tt unrmal-u hase separation isa Bcttrrcompalibility eTW tinareasHeOdpodvlaAeiectrocdery Cdt detection as wellaabettcf of the adalAutindie go-oriaegamu modile phase 31 50 5 1110 saAPlr m itv . A