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Introduction to Modern Liquid Chromatography, Third Edition part 80. 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. . | 746 PREPARATIVE SEPARATIONS 1 10 10 1 Figure 15-9 Isocratic separation of a two-component sample as a function of sample size. Computer simulations based on the Langmuir isotherm Conditions 250 x 50-mm column 7- im 210 mL min flow rate N 800 k 1 and 1.5 respectively. Sample weights indicated in figure. Adapted from 9 . Section 9.3.1 . If thcnxc is anydoubt as totheidentity oftheproductpeakin these iiiitialscpatatioiis tin s cnn bn confitmed b.c separate mjnction oi pure product. Step 2 of Figure 15.8. Following the adjustment of B in step 1 separation conditions ort v ax l for theltstt nostible suparatite cf theproduct pea- from adjacent impntitypeoks.Usuol ihe produise peek slnoilclbo placsd mMwa0 bntwtev the adjacecsimpurities on each side. Previous chapters provide a detailed discussion of how selectivity a can be optimized depending on the kind of sample and whether NPC or RPC is used see Table2.2 for eonCitions sOas affect v . Becanseof fhe importancenOmennniumg u io c eq K Eq. en.ei mocework on str. d maybe warrantedot ontueeudle c u an U s d isSsi r acutiodr. Unlikeeheceteof ooalyeicai separation . pro tC isislmpnrranto-ifpossibie sn rcoid separation sonditioos that resulrin On rogizationoetheprodoeh mdiecolc eec Ceciion ea.3.e.C aoi the discussion oeFig.15.6 . Oorgeohaoees in a iwirbcoe iemzlcotOc prodtim are most likely fdbtachieveOOy e change in B-soivent orthfcolumu. 15.3 ISOCRATIC ELUTION 747 The same conditions used for this optimized separation can be used to assay fractions collected during prep-LC but with the initial small-scale column . If the resolution of the product peak is s ri 2 desirable for prep-LC the assay separations can be carried out with a shorter column and increased flow rate to speed up fraction analysis. Step 3ofFigurei5.8. n initial estimate ofthe weight of injected sample is possible ba xl eif1 Equaium HA . 2. a value of a 3 eho solemn capacity ws and 4.arough estimate h vam e joutity To-piodoesieilicsaniidcj. .ore 150 x 4.6-mm
