Electrospun polystyrene/Aliquat 336 for preconcentration and determination of thiocyanate in flow analysis

A new extracting polymer wool was prepared from polystyrene (PS) and the commercial extractant Aliquat 336 by electrospinning and its potential as a packing material for an online preconcentration column in an automated flow injection system was investigated for the determination of thiocyanate (SCN−). The formation of the wool fibres was confirmed by scanning electron microscopy (SEM). The polymer wool was inserted into a glass tube to prepare a column. SCN− solutions of different volumes (2-10 mL) were passed through the fibre-packed column where SCN− was extracted by the fibres. The columnwas then eluted with a small volume of 1MNaNO3 solution. The eluatewas mixed with an iron(III) solution and the resulting coloured complex (FeSCN2+) was detected colorimetrically. The system successfully achieved 21-fold preconcentration of SCN−. A linear calibration curve was obtained in the range from 0.02 to 1.0 mg L−1 SCN− with a sampling rate of 9 h−1. To the authors’ best knowledge this is the first time electrospun fibres containing a liquid extractant have been used for preconcentration in a flow analysis system.