Electrochemically controlled in-tube solid phase microextraction

Seyyed Hamid Ahmadi; Ahmad Manbohi; Kourosh Tabar Heydar

doi:10.1016/j.aca.2014.10.040

Electrochemically controlled in-tube solid phase microextraction

Anal Chim Acta. 2015 Jan 1:853:335-341. doi: 10.1016/j.aca.2014.10.040. Epub 2014 Oct 30.

Authors

Seyyed Hamid Ahmadi¹, Ahmad Manbohi², Kourosh Tabar Heydar²

Affiliations

¹ Chemistry & Chemical Engineering Research Center of Iran, P.O. Box 14334-186, Tehran, Iran. Electronic address: ahmadi@ccerci.ac.ir.
² Chemistry & Chemical Engineering Research Center of Iran, P.O. Box 14334-186, Tehran, Iran.

PMID: 25467477
DOI: 10.1016/j.aca.2014.10.040

Abstract

We report a new in-tube solid phase microextraction approach named electrochemically controlled in-tube solid phase microextraction (EC in-tube SPME). This approach, which combined electrochemistry and in-tube SPME, led to decrease in total analysis time and increase in sensitivity. At first, pyrrole was elctropolymerized on the inner surface of a stainless steel tube. Then, the polypyrrole (PPy)-coated in-tube SPME was coupled on-line to liquid chromatography (HPLC) to achieve automated in-tube SPME-HPLC analysis. After the completion of EC-in-tube SPME-HPLC setup, the PPy-coated tube was used as working electrode for uptake of diclofenac as target analyte. Extraction ability of the tube in presence and in absence of applied electrical field was investigated. It was found that, under the same extraction conditions, the extraction efficiency could be greatly enhanced by using the constant potential. Important factors are also optimized. The detection limit (S/N=3) and precision were 0.1 μg L(-1) and 4.4%, respectively.

Keywords: Diclofenac; Electrochemically controlled in-tube solid phase microextraction; Electropolymerization; Polypyrrole.