In liquid chromatography, buffer solution is often added to the mobile phase, one of the purposes is to make the entire HPLC system charge a stable chemical environment, so that the detection has better reproducibility. If the pH of the system is not stable enough, there will be various problems Read more…
1. Properties of peptides Polypeptide is a compound formed by connecting multiple amino acids in sequence. Amino acids are amphoteric compounds with the characteristics of zwitterions. 2. Factors Affecting Peptide Separation Column packing pore size (120Å, 300Å) Additives and concentrations (formic acid, ion pair reagents) pH Elution solvent (acetonitrile, methanol, Read more…
What kind of strange chemical reaction will happen when the medium pressure glass column meets the bulk media? It is a high-efficiency purification tool, a low-cost purification method, and a new user experience. Let medium pressure chromatography speed up purification, save time for yourself, and make “passing the column” no Read more…
When you are doing daily testing, you will find that some items, such as sodium heptane sulfonate, tetrabutylammonium hydroxide, tetrabutylammonium bromide and other reagents are added to the mobile phase used in the test standard. We call these reagents ion pairing Reagents, which can be used to improve separation and Read more…
There are many types of vials, such as injection vials, storage vials, headspace vials, etc., and each type contains various “members”. liner bottle The liner bottle is also a type of storage bottle, because its interior is similar to the liner structure, it is called a liner bottle. The liner Read more…
In the actual development of separation methods, especially for the separation and analysis of complex pharmaceutical impurities, the following problems are often encountered: How many impurities are present in the drug? What are these impurities? Can these impurities all be detected in the HPLC separation system? Where do they peak? Read more…
In the process of analysis and testing, compounds with higher polarity are usually poorly retained on conventional non-polar columns. Even if the organic phase ratio is reduced to a very low level, it is difficult to achieve retention enhancement, which is easily interfered by blank solvents or blank excipients. Therefore, Read more…
Hydrophobic interaction chromatography (HIC) is a very valuable tool in protein purification technology. After the protein is bound to the medium, it must be eluted and collected to obtain the target protein. In most cases, the elution process separates or removes protein impurities from the target protein. Sometimes protein impurities Read more…
As we all know, chromatography can solve the problem of separation and analysis of complex multi-component mixtures such as homologues and isomers with similar physical constants and similar chemical properties, and can not only identify compounds but also do quantitative determination. Chromatography is based on quantitative analysis based on the Read more…
In SPE solid phase extraction products, the eluent is critical to the entire column passing process. Welch materials provides different eluent options for different types of columns, so that customers can better choose suitable products. When examining the selection of elution solvent, the polarity index of the solvent, the choice Read more…