Preparative high pressure liquid chromatography

Preparative high-pressure liquid chromatography, which is the only technique currently available that has sufficiently high resolving power to separate a pair of tunichromes. 

Preparative High Pressure Liquid Chromatography, HPLC, proved to be a good technique for separating tautomer complexes. For example, all three possible bis(thyminato) complexes of cis-Pt(II), cis-Pt(NH3)g(TH-N1)2, cis-Pt(NH.)2(TH-N1)(TH-N3), and cJ -Pt(NH )2(TH-N3)2 have been isolated (31). 

Carmella, S.G., S.S. Hecht, and D. Hoffmann Subfractionation of the weakly acidic fraction of cigarette smoke condensate by preparative high pressure liquid chromatography 32nd Tobacco Chemists Research Conference, Program Booklet and Abstracts, Vol. 32, Paper No. 42, 1978, p. 23. 

Analytical and preparative high pressure liquid chromatography (HPLC) system equipped with C18 columns see Note 2). 

Chocolate liquor is the solid or semiplastic food prepared by finely grinding the nib of the cacao bean. It is commonly called baking chocolate, unsweetened chocolate, or bitter chocolate and, in Europe, is frequently referred to as chocolate mass or cocoa paste. Chocolate liquor is essentially the starting point from which all chocolate products are produced. Table 5 lists the theobromine and caffeine content of 22 various chocolate liquor samples determined by high pressure liquid chromatography (HPLC). The liquors averaged 1.22% theobromine and 0.214% caffeine.27- 28 The ratio of theobromine to caffeine ranged from 2.5 1 to 23.0 1. 

The values of ks/kp for partitioning of carbocations are most conveniently determined as the ratio of the yields of products from the competing nucleophile addition and proton transfer reactions (equation 1 derived for Scheme 2). The determination of these product yields has been simplified in recent years by the application of high-pressure liquid chromatography (HPLC). Typically, the product peaks from an HPLC analysis are detected and quantified by UV-vis spectroscopy. In cases where the absorbance of reactants and products is small, substrates may be prepared with a chromophore placed at a sufficient distance so that its effects on the intrinsic reactivity of the carbocationic center are negligible. For example, the aliphatic substrates [1]-Y have proved to be very useful in studies of the reactions of the model tertiary carbocation [1+].21,23... 

The synthesis of 6-hydroxy fluvastatin with M. rammaniana DSM 62752 gave high conversion (>95 %) in shake flask culture on 400 mL scale with 0.1 g L of fluvastatin as well as on 22 L scale in a Wave bioreactor-fed batch process at a final substrate concentration of 0.4 g L Instead of the partial purification by a second solid-phase extraction described above, 6-hydroxy fluvastatin can be obtained in high purity ( 95 %) by, for example, preparative medium-pressure liquid chromatography (MPLC) on RP18 silica gel. ... 

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