Optimisation of asymmetric flow field-flow fractionation for the characterisation of polydisperse TiO2 with applications in food and feed

In the present work an optimisation process for the characterisation of a polydisperse TiO2 is presented. As a first step probe ultrasonication was optimised in which the amplitude and time were the selected variables in order to disperse, i.e. to break up agglomerates and/or aggregates of the material. The results showed that high amplitudes favoured a better dispersion while time had no impact. In a next step the important factors of Assymmetric Flow Field Flow Fraction (AF4), namely cross flow (CF), detector flow (DF), cross flow rate or exponential decay of the cross flow (CFexp) and focus time (Ft) were studied by experimental design. Firstly a full factorial design was employed to establish the statistically significant factors (p-level < 0.05). Then, the information obtained from the full factorial design was utilised to apply a central composite design, in order to get the following optimum conditions of the system: CF, 1.6 mL/min; DF, 0.4 mL/min; Ft, 5 min and CFexp 0.6. Once the optimum conditions were obtained the stability of the dispersed sample was measured during 24 h by analysing 10 replicates with AF4, in order to assess the performance of the optimised dispersion protocol. Finally, the effect of the temperature on the particle size distribution, recovery and retention time was studied in the range of 25-45 °C, to check whether the method was robust against the variation of the temperature.

OMAR ONAINDIA Jone;  BOIX SANFELIU Ana;  KERCKHOVE Giovani;  VON HOLST Christoph; 

2017-02-02

TAYLOR & FRANCIS LTD

JRC99241

1944-0049,   

http://dx.doi.org/10.1080/19440049.2016.1239031,    https://publications.jrc.ec.europa.eu/repository/handle/JRC99241,   

10.1080/19440049.2016.1239031,