A novel fourth-order calibration method based on alternating quinquelinear decomposition algorithm for processing high performance liquid chromatography–diode array detection– kinetic-pH data of naptalam hydrolysis

• Five-way HPLC–DAD–kinetic-pH data were obtained for the first time.
• A new algorithm, alternating quinquelinear decomposition (AQQLD), was developed.
• Simulated data and real data were analyzed to explore the performance of AQQLD.
• PARAFAC and AQQLD were applied to investigate the kinetics of naptalam.
• It indicates the potential for the use of fourth-order data in complex systems.

Five-way high performance liquid chromatography–diode array detection (HPLC–DAD)–kinetic-pH data were obtained by recording the kinetic evolution of HPLC–DAD signals of samples at different pH values and a new fourth-order calibration method, alternating quinquelinear decomposition (AQQLD) based on pseudo-fully stretched matrix forms of the quinquelinear model, was developed. Simulated data were analyzed to investigate the performance of AQQLD in comparison with five-way parallel factor analysis (PARAFAC). The tested results demonstrated that AQQLD has the advantage of faster convergence rate and being insensitive to the excess component number adopted in the model. Then, they have been successfully applied to investigate quantitatively the kinetics of naptalam (NAP) hydrolysis in two practical systems. Additionally, the serious chromatographic peak shifts were accurately corrected by means of chromatographic peak alignment method based on abstract subspace difference. The good recoveries of NAP were obtained in these samples by selecting the time region of chromatogram. The elution time, spectral, kinetic time and pH profiles resolved by the chemometric techniques were in good agreement with experimental observations. It demonstrates the potential for the utilization of fourth-order data for some complex systems, opening up a new approach to fourth-order data generation and subsequent fourth-order calibration.

Figure optionsDownload as PowerPoint slide