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Instability of HPLC Solvents

Modes of Liquid Chromatography Solvents for Liquid Chromatography Instability of HPLC Solvents... [Pg.118]

Because of the instability of cyanohydrins, the characterization of cyanohydrins mostly should be hydroxyl protected. In 2001, Gerrits et al. [26] investigated the influence of solvent composition on the stability of unprotected cyanohydrins and then described a method to analyze unprotected cyanohydrins (with regard to enantiomeric purity and conversion) via chiral high-performance liquid chromatography (HPLC). Hernandez et al. [27] and the groups... [Pg.108]

This knowledge encourages us to apply biomimetic membranes for molecular recognition systems such as HPLC. However, lipid membrane systems suffer from a serious problem owing to their instability in organic solvents. To overcome this problem, we have reported the use of poly(octadecyl acrylate)-grafted silica (Sil-ODA ) as a lipid membrane analogue for stationary phases in RP-HPLC. Poly(octadecyl acrylate) cannot... [Pg.2147]

In addition, sometimes a normal-phase HPLC method at subambient temperature must be applied for analytes that are extremely prone to hydrolysis. In the synthesis of leukotriene D4 antagonist, accurate quantitation of mesylate intermediate is essential for process optimization. Owing to its inherent instability, analysis of mesylate intermediate must be carried out under normal-phase conditions with nonprotic solvents however, significant cycliza-tion of mesylation was stiU observed in such condition at room temperature. The authors concluded that the on-column reaction of the mesylate was silica-catalyzed cyclization. By conducting the normal-phase HPLC analysis at -30 C, it was demonstrated that on-column cyclization was adequately inhibited [30]. [Pg.252]

The stability of all components of the chromatographic system must be assured for the complete operation time. The solvent must be chemically inert to all kinds of reaction. Neither an instable solvent, which for example tends to form peroxides, nor a solvent that reacts with the sample or the adsorbent is suitable for an economically successful solution of the separation problem. Of course, corrosion of the HPLC unit must be prevented, too. [Pg.117]

A solvent gradient is usually employed to resolve individual molecular species with a reversed-phase HPLC column. Changes in the components of the mobile phase might also cause ionization instability and/or affect ionization efficiency of lipid species eluted at different mobile phase composition. [Pg.73]

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HPLC solvents

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