High-performance 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. 

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... 

Standards a stock solution (2.5 mM) of SN-38 glucuronide (kindly supplied by Yakult Honsha Co. Ltd.) is dissolved in 5 mL of methanol. A working solution (0.5-250 iiM) for calibration curves is prepared by the serial dilution of the 2.5 mM stock solution with high-performance liquid chromatography (HPLC) elution buffer. 

The PLGA-PEG-PLGA triblock copolymer was dissolved in the cold water at 5 °C to make a 23 wt% solutioa Insulin solutions were prepared in buffer (isotonic 10 mM PBS, pH 7.4) to a concentration of 5.04 mg/nil arui zinc was added (0.0, 0.2 wt%) to the hydrogel solutioa Then 2 ml of each formulation were placed in vials, incubated at 37 °C until forming gels, and 10 ml of PBS solution was added as a release medium. Release medium sarrqrles were withdrawn and replaced inunediately to keep the sink condition. Th were analyzed by reversed-phase high performance liquid chromatography (RP-... 

Mahkam et al. 2009 prepared insulin-loaded modified alginate/chitosan matrix nanohydrogels. The modified nanohydrogels were characterized by SEM and Fourier transform infrared spectroscopy (FTIR). In vitro release studies were performed in acidic buffer (pH 1) and intestinal buffer (pH 7.4) with high-pressure liquid chromatography with ultraviolet detector at 210mn [43]. 

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