Spectrophotometric determination of iron species using ultrasound-assisted temperature-controlled deep eutectic solvent dispersive liquid-phase microextraction and multisimplex optimisation

A simple, quick and disperser-solvent-free analytical method based on ultrasound-assisted temperature-control deep eutectic solvent dispersive liquid-phase microextraction (UA-TC-DES-DLPME) in combination with spectrophotometry was developed for the separation/preconcentration and determination of iron species. In this method, Fe(II) was complexed with 2,4,6-tri(2MODIFIER LETTER PRIME-pyridyl)-l,3,5-triazine (TPTZ), and extracted into a hydrophobic deep eutectic solvent (DES) consisting of choline chloride and 4-chlorophenol (ChCl/4-Chph). The dispersion of DES in aqueous phase was speeded up by ultrasound waves and temperature-control process without using any organic dispersive solvent. Total iron concentration was obtained after reduction of Fe(III) to Fe(II) with hydroxylamine hydrochloride, and the amount of Fe(III) was calculated according to the difference between the concentration of total iron and Fe(II). At optimum conditions that obtained using Multisimplex method, the calibration curve was linear over the range of 5.0-100.0 mu g L (-1) with the detection limit of 1.2 mu g L (-1). The intra- and inter-day relative standard deviations (RSDs) at 20 mu g L-1 level of Fe(II) (n = 5) were 3.6 and 4.5.%, respectively. The proposed method was successfully applied to the determination of iron species in water samples.

Automated summary

A simple and quick analytical method based on ultrasound-assisted temperature-control deep eutectic solvent dispersive liquid-phase microextraction (UA-TC-DES-DLPME) combined with spectrophotometry was developed for the separation/preconcentration and determination of iron species. The method showed a wide linear range, low detection limit, and good reproducibility under optimized conditions.