Liquid chromatography buffer preparation

In the separation of biomolecules, sample preparation almost always involves the use of one or more pretreatment techniques. With high-performance liquid chromatography (HPLC), no one sample preparation technique can be appHed to all biological samples. Several techiques may be used to prepare the sample for injection. For example, complex samples require some form of preffactionation before analysis, samples that are too dilute for detection require concentration before analysis, samples in an inappropriate or incompatible solvent require buffer exchange before analysis, and samples that contain particulates require filtration before injection into the analytical instrument. 

Introduction to fast performance liquid chromatography. Review Buffer preparation, Definitions of pH, Henderson-Hasselbalch equation, and Buffer calculations. 

According to the USP 26 and the Indonesian Pharmacopoeia, the assay for mefenamic acid is performed by a liquid chromatography method. A buffer solution is prepared as a 50 mM solution of monobasic ammonium phosphate, adjusted with 3 M ammonium hydroxide to a pH of 5.0. The system uses a filtered and degassed mixture of acetonitrile, buffer solution, and tetrahydrofuran (23 20 7) as the mobile phase. The liquid chromatograph is equipped with a 254 nm detector and a 4.6 mm x 25 cm column that contains packing LI. The flow rate is about 1 mL/min. The column efficiency is not less than 8200 theoretical plates, the tailing factor for the analyte peak is not more than 1.6, and the relative standard deviation for replicate injections is not more than 1.0% [1, 4]. 

To determine the stability of silicone polyether copolymers, solutions were prepared by dispersing the copolymers in standard buffer solutions ranging in pH from 2 to 12 and concentrations ranging from 0.5 to 2.0 weight percent. High-performance liquid chromatography (HPLC) was used to monitor the stability of the polymers over time. Reverse-phase HPLC is an ideal method for... 

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