Application of a new fiber coating based on electrochemically reduced graphene oxide for the cold-fiber headspace solid-phase microextraction of tricyclic antidepressants

Abstract

A new fiber based on the electrochemical reduction of graphene oxide was prepared on a copper wire for solid-phase microextraction (SPME) applications. The prepared fiber was used for the SPME and gas chromatographic analysis of tricyclic antidepressants (TCADs), including amitriptyline, trimipramine, and clomipramine. The feasibility of direct-immersion and headspace modes of SPME for the determination of TCADs was studied. The effects of four parameters including pH, salt content, extraction temperature with and without cooling the fiber, and extraction time were investigated. The comparison showed that headspace cold fiber SPME results in the best outcome for the extraction of TCADs. Under the optimized conditions of this mode, the calibration curves were linear between 2.0 and 500 ng/mL and the detection limits were between 0.30 and 0.53 ng/mL. The intraday and interday RSDs obtained at 20 ng/mL (n = 5), using a single fiber, were 5.5-9.0 and 7.5-9.8, respectively. The fiber to fiber repeatability (n = 4), expressed as the RSD, was between 12.8 and 13.2% at a 20 ng/mL concentration level. The method was successfully applied to the analysis of TCADs in plasma samples showing recoveries from 73 to 96%.

Development of Novel Solid-Phase Microextraction Fibers

“…Thus, in the following studies, graphene oxide (GO), which is less likely to aggregate in its suspension than graphene, was firstly chemically bonded to substrates, then reduced to graphene on the substrates [26,82,83]. Banitaba et al [84] prepared a SPME fiber by electrochemically reducing GO on the surface of copper wire. Liu et al [31] directly oxidized the surface of pencil lead and then reduced it for the preparation of a graphene fiber (Fig.…”

“…Due to the superior thermal conductivity of graphene and GO, the fibers of graphene and GO coated on the metal wires were also used for headspace-cold fiber-SPME [84,88]. Cooling the fibers could increase the partition coefficients between the fibers and sample matrices, since adsorption of analytes on graphene coatings were exothermic processes, which could potentially promote the sensitivity of SPME.…”

Direct synthesis of nitrogen-doped graphene on platinum wire as a new fiber coating method for the solid-phase microextraction of BXes in water samples: Comparison of headspace and cold-fiber headspace modes

“…The injector and detector temperatures were set to 200ºC and 300ºC, respectively. The injection was undertaken in split mode with split ratios of 1:10 and 1:20 for the first 2 min and the remaining run time, respectively due to avoid of overlap or flatting of some peaks and prevent of probably leakage which may be new fiber has [12,[33][34][35]. Nitrogen (>99.999%) at a constant pressure of 4 psi was used as the carrier gas.…”

“…However, there are still many deficiencies to be addressed, such as poor thermal, mechanical and chemical stabilities, poor sensitivity and selectivity, and the limited range of polar samples covered. Most of the commercially available fibers are nonpolar; other relatively polar fibers suffer from intense issues in terms of thermal instability [12]. In order to overcome some of these disadvantages and enhance SPME efficiency, new constructional approaches have been developed, including membrane-protected SPME [13], in-tube SPME [14], electrochemically assisted SPME [15], ultrasound-assisted SPME [16], and cold fiber SPME (CF-SPME) [17].…”

Fast vaporization solid phase microextraction and ion mobility spectrometry: A new approach for determination of creatinine in biological fluids

“…A practical solution for increasing the extraction efficiency of SPME is cooling the fiber while the vial is heating which has showed excellent extraction efficiencies [14,[24][25][26]. Haddadi et al [27] developed a cold fiber SPME (CF-SPME) device based on thermoelectric cooler (TEC) devices.…”