An improved microextraction method based on continuous sample drop flows and solidification of switchable hydrophilic fatty acid for the speciation of chromium in aqueous samples

ABSTRACT

Centrifuge less continuous sample drop flow-based microextraction is combined with graphite furnace atomic absorption spectrometry to develop a novel analytical procedure for the speciation and preconcentration of the trace amounts of chromium in the aqueous samples. The extraction procedure involves the sequential addition of the aqueous sample in form fine droplets through a switchable hydrophilic fatty acid as an extraction phase. In this study, the centrifugation step was eliminated by applying the salting-out phenomenon. The influence of the main variables on the efficiency of the procedure was evaluated by chemometric methods. Under optimised conditions, the linearity ranges of the proposed method are in the range of 1–20 µg L⁻¹ with correlation coefficients exceeding 0.9993. The limit of detection and limit of quantification were 0.29 and 0.87 µg L⁻¹, respectively. The recovery of analyte in tap, well, and river and wastewater ranged between 95.2% and 105.0% with relative standard deviations ranging from 1.30% to 5.78%. Hence, the method was successfully applied to the analysis of chromium in water samples.

KEYWORDS:

• Continuous sample drop flow-based microextraction
• centrifuge less
• switchable hydrophilic fatty acid
• chromium speciation
• aqueous samples

Acknowledgments

This study was supported by grants from Varamin-Pishva Branch, Islamic Azad University.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed here.