Handling of highly coeluted chromatographic peaks by multivariate curve resolution for a complex bioanalytical problem: Quantitation of selected corticosteroids and mycophenolic acid in human plasma

Abstract

The present study describes the analytical performance of a fast-elution protocol and smart methodology based on multivariate curve resolution-alternating least square (MCR-ALS) modeling of high performance liquid chromatography with photodiode-array detection (HPLC-DAD) data for simultaneous determination of prednisolone (Predl), methylprednisolone (Mpredl) and mycophenolic acid (MPA) in plasma samples. The LC method optimized at two isocratic reverse phase over a symmetric C18 column, a 60:40 (v/v) mixture of acetonitrile and water (0.02 M KH2PO4 (pH = 3.7) buffer solution) and a 10:70:20 (v/v/v) mixture of acetonitrile, methanol and water. The most challenges in the present study were the severe coelution of analytes of interest with each other and the matrix interferences, and high spectral similarity of selected corticosteroids, depending on the mobile phase method. To circumvent these drawbacks, the whole chromatographic runs were divided into two sections. Then, the matrix augmentation in spectra and retention time direction were implemented for the first and second regions, respectively. Highly acceptable resolution and quantification results were obtained. The average recoveries were 97.3% and 102.1% for Predl, 96% and 98.6% for Mpredl and 97.7% and 100.8% for MPA, using two mobile phase conditions, respectively. Accurate and precise results, elimination of expensive and time consuming sample pretreatment steps and a very short chromatographic run time, are among the advantages of the presented method.