Preconcentration of digoxin using a synthetic imprinted polymer deposited upon the surface of double-layered hydroxides on porous anodised aluminium wire a triple solid-phase microextraction fibre.

INTRODUCTION: A new solid-phase microextraction fibre is fabricated through polymerisation of molecularly imprinted polymer on the surface of a layered double hydroxide framework that has been fabricated via the in situ synthesis on a non-porous anodic aluminium oxide/aluminium wire as both the substrate and the aluminium source. OBJECTIVE: The synthesized SPME fiber was performed to analyze trace digoxin in real samples. MATERIAL AND METHOD: A one-at-a-time optimization strategy was applied for optimizing the important extraction parameters such as extraction solvent, extraction time, stirring rate, pH, ionic strength, and desorption time. RESULT: Aluminum surface before and after anodizing and LDH structure reveal that anodizing and preparation LDH increases the surface area and adsorption capacity of aluminum wire. CONCLUSION: Under optimum conditions, the repeatability for one fibre (n = 3), expressed as relative standard deviation (RSD %), was 5.2%.

Bio template route for fabrication of a hybrid material composed of hierarchical boehmite, layered double hydroxides (Mg-Al) and porous carbon on a steel fiber for solid phase microextraction of agrochemicals.

Nanosheets of a porous layered double hydroxide were directionally arranged on boehmite nanowires and porous carbon and used as a coating for solid-phase microextraction (SPME) method. Porous carbon tubes were prepared from goat grass and then coated with layered double hydroxide nanosheets and boehmite nanowires. The nanomaterial was placed on a stainless-steel wire which then was used for the extraction of fifteen agrochemicals from aqueous sample solutions. The extraction temperature, extraction time, ionic strength, stirring rate, and desorption temperature and time were optimized. Following thermal desorption of the agrochemicals in the injector of the gas chromatograph, they were quantified by GC/MS. Under optimum conditions, the repeatability for one fiber, expressed as relative standard deviation, was between 2.9 and 11.1%. The detection limits for the agrochemicals are between 2-29 ng L-1. The method is simple, fast, and inexpensive (in terms of equipment). The fiber is thermally stable, and the relative recoveries from spiked samples are better compared to conventional methods of extraction. Graphical abstract Schematic illustration of the preparation of three-dimensional hierarchical boehmite/ layered double hydroxides/ porous carbon (Boeh/LDH/pC) SPME fibers and application for the extraction of fifteen agrochemicals from aqueous sample solutions following quantification by GC/MS.

Carbon nanotube/layered double hydroxide nanocomposite as a fibre coating for determination the essential oils of Achillea eriophora DC with the headspace solid-phase microextraction.

The present study was conducted to synthesise a carbon nanotube/layered double hydroxide nanocomposite by an in situ growth route via electrostatic force. The fabricated carbon nanotube/layered double hydroxide nanocomposite was successful in deposition on a stainless-steel wire for the preparation of the solid-phase microextraction fibre. The produced fibers are enduring with high suitability being chemically and thermally stable capable of coupling to GC and GC/MS. The important extraction parameters including extraction temperature, extraction time, sample mass and added water were simultaneously optimised using an optimisation approach. I comparison to hydrodistillation (HD), headspace single drop micro-extraction) HS-SPME (is advantageous regarding little sample level, time-efficiency, convenience and low cost.

Rapid analysis of Achillea tenuifolia Lam essential oils by polythiophene/hexagonally ordered silica nanocomposite coating as a solid-phase microextraction fibre.

In this work, a highly porous fibre coated with polythiophene/hexagonally ordered silica nanocomposite (PT/SBA-15) was prepared and used for extraction of essential oils with microwave-assisted distillation headspace solid phase microextraction (MA-HS-SPME) method. The prepared nanomaterials were immobilised on a stainless steel wire for fabrication of the SPME fibre. Using MA-HS-SPME followed by GC-MS, 24 compounds were separated and identified in Achillea tenuifolia, which mainly included limonene (28.6%), α-cadinol (12.7%), borneol (6.7%), caryophyllene oxide (3.2%), bornyl acetate (4.3%), camphene (3.2%) and para-cymene (2.3%). The experimental results showed that the polythiophene/hexagonally ordered silica nanocomposite fibres were suitable for the semi-quantitative study of the composition of essential oils in plant materials and for monitoring the variations in the volatile components of the plants.

Fast determination of Ziziphora tenuior L. essential oil by inorganic-organic hybrid material based on ZnO nanoparticles anchored to a composite made from polythiophene and hexagonally ordered silica.

In this paper, for the first time, an inorganic-organic hybrid material based on ZnO nanoparticles was anchored to a composite made from polythiophene and hexagonally ordered silica (ZnO/PT/SBA-15) for use in solid-phase fibre microextraction (SPME) of medicinal plants. A homemade SPME apparatus was used for the extraction of volatile components of Ziziphora tenuior L. A simplex method was used for optimisation of five different parameters affecting the efficiency of the extraction. The main constituents extracted by ZnO/PT/SBA-15 and PDMS fibres and hydrodistillation (HD) methods, respectively, included pulegone (51.25%, 53.64% and 56.68%), limonene (6.73%, 6.58% and 8.3%), caryophyllene oxide (5.33%, 4.31% and 4.53%) and 1,8-cineole (4.21%, 3.31% and 3.18%). In comparison with the HD method, the proposed technique could equally monitor almost all the components of the sample, in an easier way, in a shorter time and requiring a much lower amount of the sample.