PEI Series (Analysis of Polyethylenimine)

Polyethylenimine (PEI) has multiple industrial, medical, biological and research applications. It is a difficult compound to analyze by HPLC. The problem has many degrees of difficulty. It is not a single compound, but a mixture of different molecules with different lengths and branching structures It has multiple charges in acidic and neutral pH, which is most common in HPLC PEI molecules have no UV chromophores and can not be measured by UV-Vis detector, the most common detector in analytical laboratories.

Instead, this analysis requires MS, CAD, ELSD with their own limitations of the mobile phase composition It irreversibly binds to silica-based columns, limiting the type of adsorbents that can be used for analysis If composition of PEI with proteins or peptides needs to be analyzed then the peptide/protein signal can interfere with PEI peak SIELC developed a new methodology and a corresponding HPLC column to address these difficulties and offer a simple and reliable method for PEI quantitation in any liquid samples.

The method is based on forming a complex of PEI with Cu (II) which has strong UV and visible light adsorption maximums. This complex can be measured by UV-Vis detector and can be separated from Cu (II) signal and other Cu complexes using specially designed PEI specific HPLC column.

SIELC PEI Brochure