title: Mathematical modeling of dispersion in single interface flow analysis.
abstract: This work describes the optimization of the recently proposed fluid management methodology single interface flow analysis (SIFA) using chemometrics modelling. The influence of the most important physical and hydrodynamic flow parameters of SIFA systems on the axial dispersion coefficients estimated with the axially dispersed plug-flow model, was evaluated with chemometrics linear (multivariate linear regression) and non-linear (simple multiplicative and feed-forward neural networks) models. A D-optimal experimental design built with three reaction coil properties (length, configuration and internal diameter), flow-cell volume and flow rate, was adopted to generate the experimental data. Bromocresol green was used as the dye solution and the analytical signals were monitored by spectrophotometric detection at 614 nm. Results demonstrate that, independent of the model type, the statistically relevant parameters were the reactor coil length and internal diameter and the flow rate. The linear and non-linear multiplicative models were able to estimate the axial dispersion coefficient with validation r(2)=0.86. Artificial neural networks estimated the same parameter with an increased accuracy (r(2)=0.93), demonstrating that relations between the physical parameters and the dispersion phenomena are highly non-linear. The analysis of the response surface control charts simulated with the developed models allowed the interpretation of the relationships between the physical parameters and the dispersion processes.
authors.affiliation: REQUIMTE, Serviço de Química-Física, Faculdade de Farmácia, Universidade do Porto, Rua Anibal Cunha, 164, 4099-030 Porto, Portugal.
authors.forename: S Sofia M
authors.initials: SS
authors.lastname: Rodrigues
authors.forename: Karine L
authors.initials: KL
authors.lastname: Marques
authors.forename: João A
authors.initials: JA
authors.lastname: Lopes
authors.forename: João L M
authors.initials: JL
authors.lastname: Santos
authors.forename: José L F C
authors.initials: JL
authors.lastname: Lima
mesh_terms: D001961:Bromcresol Green / Q000737:chemistry; D017022:Flow Injection Analysis / Q000295:instrumentation / Q000379:methods; D016014:Linear Models; D008962:Models, Theoretical; D015999:Multivariate Analysis; D016571:Neural Networks, Computer
chemical_list: D001961:Bromcresol Green