A solid-phase microextraction platinized stainless steel fiber coated with a multiwalled carbon nanotube-polyaniline nanocomposite film for the extraction of thymol and carvacrol in medicinal plants and honey

• Published in: Journal of Chromatography A Vol. 1406; pp. 87 - 93
• Main Authors: Ghiasvand, Alireza, Dowlatshah, Samira, Nouraei, Nadia, Heidari, Nahid, Yazdankhah, Fatemeh
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 07.08.2015
• Subjects: Aniline Compounds - chemistry; Carvacrol; Chemistry Techniques, Analytical - instrumentation; Chemistry Techniques, Analytical - methods; Electrophoretic deposition; Honey; HPLC; Limit of Detection; Monoterpenes - isolation & purification; Multiwalled carbon nanotube/polyaniline; Nanocomposites - chemistry; Nanotubes, Carbon - chemistry; Plants, Medicinal - chemistry; Solid Phase Microextraction - instrumentation; Solid-phase microextraction; Stainless Steel - chemistry; Thymol; Thymol - isolation & purification; Water Pollutants, Chemical - analysis; Solid-phase microextraction; Carvacrol; Thymol; HPLC; Multiwalled carbon nanotube/polyaniline; Electrophoretic deposition
• DOI: 10.1016/j.chroma.2015.06.052
• ISSN: 0021-9673

•It is the first use of the EPD platinization technique, to make the surface of a stainless steel SPME fiber porous and cohesive, for tight attaching of the coating.•Using the EPD strategy, for coating of the platinized stainless steel wire by MWCNTs/PANI, resulted in an SPME fiber with substantial durability, long lifetime, and acceptable efficiency.•Comparison of the proposed novel fiber, with commercial fibers, has established its preferences.•Thymol and carvacrol was successfully extracted by the proposed nanocomposite fiber, through a DI-SPME strategy, from aqueous real samples. A mechanically hard and cohesive porous fiber, with large surface area, for more strong attachment of the coating was provided by platinizing a stainless steel wire. Then, the platinized stainless steel fiber was coated with a multiwalled carbon nanotube/polyaniline (MWCNT/PANI) nanocomposite using electrophoretic deposition (EPD) method and applied for the extraction of thymol and carvacrol with direct-immersion solid-phase microextraction (DI-SPME) method followed by high-performance liquid chromatography-ultraviolet detection (HPLC-UV) quantification. To provide a larger coarse surface for the tightened attachment of coating on the fiber, a stainless steel wire was platinized using a suitable optimized EPD method. Different experimental parameters were studied and the optimal conditions were obtained as: pH of the sample solution: 2; extraction time: 60min; salt content in the sample solution: 1% w/v NaNO3; desorption time: 60min; type and volume of the desorption solvent: acetonitrile, 100μL. Under the optimized conditions, limits of detection (LODs) were 0.6 and 0.8μgmL−1 for thymol and carvacrol, respectively. Linear dynamic range (LDR) for the calibration curves of both analytes were 1–80μgmL−1. Relative standard deviation (RSD%, n=6) was 6.8 for thymol and 12.7 for carvacrol. The proposed fiber was successfully applied for the recovery and determination of thymol and carvacrol in thyme, savory, and honey samples.