Validation of a new method for spectrophotometric determination of polyethylenimine

A new method of determination of polyethylenimine (PEI) is presented. The method is fast, reliable, and easy to perform. It is based on a creation of a complex between Cu2+ and PEI and its absorption in UV–VIS spectrum. The complex has a distinct absorption peak in UV part of electromagnetic spectrum and the measurement is optimal at 285 nm. A method is thoroughly analyzed in various concentrations of both PEI and Cu2+, temperatures, times of creation of a complex, ionic strengths, background electrolytes types, and pH values. Analytical parameters of the presented method such as linearity, sensitivity, limit of detection (LOD), limit of quantification (LOQ), repeatability, and intermediate precision were also determined.