Development of direct microwave desorption/gas chromatography mass spectrometry system for rapid analysis of volatile components in medicinal plants.

A new direct microwave desorption-gas chromatography-mass spectrometry method was developed for the analysis of the essential oils of medicinal plants. A homemade direct microwave desorption system was fabricated and used for the desorption of volatile components of medicinal herbs. The desorbed volatiles are transferred directly into the gas chromatography injector for analysis in a one-step process. Approximately 0.3 g of the herb was needed for the desorption of samples in 60 s. In this study, more than 53 volatile compounds were identified and quantified for Echinophora platyloba DC as model herb sample. The results were found to be in good agreement with the conventional hydrodistillation extraction data. The described results show that direct microwave desorption is fast, simple, and easy to automate and requires only a small amount of sample. The results indicate that essential oil components valuable for varietal identification and characteristic of each variety analyzed when direct microwave desorption-gas chromatography-mass spectrometry was used for analysis.

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.

Layered double hydroxide nanoparticles as an appealing nanoparticle in gene/plasmid and drug delivery system in C2C12 myoblast cells.

Gene and drug delivery systems need crucial update in the issue of nanocarriers. Layered double hydroxides (LDHs) are known as biocompatible inorganic lamellar nanomaterials with versatile properties. In the present study, Zn/Al-LDH nanoparticle was synthesized and characterized by FTIR, XRD, SEM, TEM and Zeta potential tests and then intercalated with valproate and methyldopa by co-precipitation and ion exchange methods. These nanocarriers were applied as high activity nanolayers-based delivery systems. On the other hand, Zn/Al-LDH + plasmid/gene (pCEP4/Cdk9) evaluated on C2C12 myoblast cells. Co-operation loading indicated high efficiency of sorting and release of drugs. Additionally, the Real-Time PCR and Western blotting results for plasmid-gene (pCEP4/Cdk9) delivery showed that Zn/Al-LDH nanoparticles can be used as an effective carrier in cellular uptake and release of genes for gene therapy. Easy and cost-effective production of Zn/Al-LDH nanoparticles proposed them as potential alternatives for the traditional routs of drug/gene delivery.

A star-shaped polythiophene dendrimer coating for solid-phase microextraction of triazole agrochemicals.

A nanostructured star-shaped polythiophene dendrimer was prepared and used as a fiber coating for headspace solid phase microextraction of selected triazolic pesticides (tebuconazole, hexaconazole, penconazole, diniconazole, difenoconazole, triticonazole) from water samples. The dendrimer with its large surface area was characterized by thermogravimetric analysis, UV-Vis spectroscopy and field emission scanning electron microscopy. It was placed on a stainless steel wire for use in SPME. The experimental conditions for fiber coating, extraction, stirring rate, ionic strength, pH value, desorption temperature and time were optimized. Following thermal desorption, the pesticides were quantified by GC-MS. Under optimum conditions, the repeatability (RSD) for one fiber (for n = 3) ranges from 4.3 to 5.6%. The detection limits are between 8 and 12 pg mL-1. The method is fast, inexpensive (in terms of equipment), and the fiber has high thermal stability. Graphical abstract Schematic presentation of a nanostructured star-shaped polythiophene dendrimer for use in headspace solid phase microextraction of the triazolic pesticides (tebuconazole, hexaconazole, penconazole, diniconazole, difenoconazole, triticonazole). They were then quantified by gas chromatography-mass spectrometry.

Fast analysis of volatile compounds from Lippia citriodora with nanoporous aluminum wire as solid-phase microextraction fibres.

In this study, the efficiency of nanoporous aluminium wires as fibres for headspace solid-phase microextraction (HS-SPME) of volatile compounds from Lippia citriodora was investigated and compared with two anodised methods. The prepared fibres are durable with very good chemical and thermal stability which can be coupled to GC and GC/MS. A one at-a-time optimisation strategy was applied for optimising the important extraction parameters such as extraction temperature, extraction time, sample mass and added water. Compared with hydrodistillation (HD), HS-SPME provide the advantages of a small amount of sample, time-saving, simplicity and cheapness.

Fabrication of polyaniline-coated halloysite nanotubes by in situ chemical polymerization as a solid-phase microextraction coating for the analysis of volatile organic compounds in aqueous solutions.

We have synthesized an organic-inorganic polyaniline-halloysite nanotube composite by an in situ polymerization method. This nanocomposite is immobilized on a stainless-steel wire and can be used as a fiber coating for solid-phase microextraction. It was found that our new solid-phase microextraction fiber is an excellent adsorbent for the extraction of some volatile organic compounds in aqueous samples in combination with gas chromatography and mass spectrometry. The coating can be prepared easily, is mechanically stable, and exhibits relatively high thermal stability. It is capable of extracting phenolic compounds from water samples. Following thermal desorption, the phenols were quantified by gas chromatography with mass spectrometry. The effects of extraction temperature, extraction time, sample ionic strength, stirring rate, pH, desorption temperature and desorption time were studied. Under optimal conditions, the repeatability for one fiber (n = 5), expressed as the relative standard deviation, is between 6.2 and 9.1%. The detection limits range from 0.005 to 4 ng/mL. The method offers the advantage of being simple to use, with a shorter analysis time, lower cost of equipment and higher thermal stability of the fiber in comparison to conventional methods of analysis.

Synthesis of a metal-organic framework confined in periodic mesoporous silica with enhanced hydrostability as a novel fiber coating for solid-phase microextraction.

A metal-organic framework/periodic mesoporous silica (MOF-5@SBA-15) hybrid material has been prepared by using SBA-15 as a matrix. The prepared MOF-5@SBA-15 hybrid material was then deposited on a stainless-steel wire to obtain the fiber for the solid-phase microextraction of phenolic compounds. Modifications in the metal-organic framework structure have proven to improve the extraction performance of MOF/SBA-15 hybrid materials, compared to pure MOF-5 and SBA-15. Optimum conditions include an extraction temperature of 75°C, a desorption temperature of 260°C, and a salt concentration of 20% w/v. The dynamic linear range and limit of detection range from 0.1-500 and from 0.01-3.12 ng/mL, respectively. The repeatability for one fiber (n = 3), expressed as relative standard deviation, is between 4.3 and 9.6%. The method offers the advantage of being simple to use, rapid, and low cost, the thermal stability of the fiber, and high relative recovery (compared to conventional methods) represent additional attractive features.

Synthesis of carbon nanotube/layered double hydroxide nanocomposite as a novel fiber coating for the headspace solid-phase microextraction of phenols from water samples.

In this research, a carbon nanotube/layered double hydroxide nanocomposite was synthesized by an in situ growth route by electrostatic force. The prepared carbon nanotube/layered double hydroxide nanocomposite was successfully prepared and deposited on a stainless-steel wire for the fabrication of the solid-phase microextraction fiber. The fiber was evaluated for the extraction of phenolic compounds from water samples. Analytical merits of the method, under optimum conditions (extraction temperature: 75°C, extraction time: 30 min, desorption time: 2 min, desorption temperature 260°C, salt concentration: 10% w/v) are 0.01-300 ng/mL for the linear dynamic range and 0.005-0.08 for the limit of detection. In optimum conditions, the repeatability for one fiber (n = 3), expressed as relative standard deviation, was between 6.5 and 9.9% for the phenolic compounds.

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.

Nanoscale-supported heteropoly acid as a new fiber coating for solid-phase microextraction coupled with gas chromatography-mass spectrometry.

In the present study, 12-tungstophosphoric (PW) acid as heteropoly acid, supported on silica-coated γ-Fe2O3 nanoparticles (NPs), was used as a new fiber coating for solid-phase microextraction (SPME). The γ-Fe2O3@SiO2-PW nanocomposite with high surface area was synthesized and characterized by SEM and FT-IR. The prepared nanocomposite was immobilized on a stainless steel wire for fabrication of the SPME fiber. The fiber was evaluated for the extraction of some phenolic compounds (PCs) from water sample in combination with gas chromatography-mass spectrometry (GC-MS). A one-at-a-time optimization strategy was applied for optimizing the important extraction parameters such as extraction temperature, extraction time, ionic strength, stirring rate, pH, and desorption temperature and time. In optimum conditions, the repeatability for one fiber (n=3), expressed as relative standard deviation (R.S.D. %), was between 4.8% and 9.6% for the test compounds. The detection limits for the studied compounds were between 0.004 and 0.05 pg mL(-1). The developed method offers the advantage of being simple to use, with shorter analysis time, lower cost of equipment, thermal stability of fiber and high relative recovery in comparison to conventional methods of analysis.

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.

Polypyrrole-montmorillonite nanocomposite as sorbent for solid-phase microextraction of phenolic compounds in water.

A fiber-coated polypyrrole-montmorillonite nanocomposite was prepared for solid-phase microextraction. The fiber coating can be prepared easily; it is mechanically stable and exhibits relatively high thermal stability. The prepared fiber was evaluated for the extraction of some phenolic compounds from aqueous sample solutions by gas chromatography-mass spectrometry. The effects of the extraction and desorption parameters including extraction time, extraction temperature, stirring rate, ionic strength, pH and desorption temperature and time have been studied. At optimum conditions, the repeatability for one fiber (n = 5), expressed as % relative standard deviation was between 6.5 and 7.8% for the phenolic compounds. The detection limits for the studied phenolic compounds were between 0.05-1.3 ng/mL. The developed method offers the advantage of being simple to use, with shorter analysis time, lower cost, thermal stability of the fibers, and high relative recovery in comparison to conventional methods of analysis.

Three dimensionally honeycomb layered double hydroxides framework as a novel fiber coating for headspace solid-phase microextraction of phenolic compounds.

A new solid phase microextraction (SPME) fiber based on high-temperature three dimensionally honeycomb layered double hydroxide (TDH-LDH) material is presented. The fiber coating can be prepared easily, it is mechanically stable and exhibits relatively high thermal stability. This study shows that three dimensionally honeycomb layered double hydroxide generated porous morphology. The TDH-LDH material was tested for the extraction of some phenolic and polycyclic aromatic hydrocarbon compounds from aqueous sample solutions in combination with gas chromatography-mass spectrometry (GC-MS). The TDH-LDH fiber contains polar groups and its efficiency for non-polar polycyclic aromatic hydrocarbon compounds was lower than phenolic compounds. On the other hand, a high tendency towards the adsorption of polar phenolic compounds was observed for the proposed fiber. The effects of the extraction and desorption parameters including extraction temperature, extraction time, ionic strength, stirring rate, pH and desorption temperature and time have been studied. In optimum conditions, the repeatability for one fiber (n=5), expressed as relative standard deviation (R.S.D. %), was between 2.8% and 7.1% for the phenolic compounds. The detection limits for the studied phenolic compounds were between 0.02 and 5.8 ng mL(-1). The developed method offers the advantage of being simple to use, with shorter analysis time, lower cost of equipment, thermal stability of fiber and high relative recovery in comparison to conventional methods of analysis.

Keggin-type heteropoly compounds supported on montmorillonite clays offering strong option for efficient solid-phase microextraction coating.

Keggin-type heteropoly compounds supported on montmorillonite clays were prepared and used as a highly porous fiber coating material for solid-phase microextraction (SPME). The prepared nanomaterial was immobilized onto a stainless steel wire for fabrication of the SPME fiber. The fiber was evaluated for the extraction of some polycyclic aromatic hydrocarbons (PAHs) from aqueous sample solutions in combination with gas chromatography-mass spectrometry (GC-MS). A one at-the-time optimization strategy was applied for optimizing the important extraction parameters such as extraction temperature, extraction time, ionic strength, stirring rate, and desorption temperature and time. In optimum conditions, the repeatability for one fiber (n=3), expressed as relative standard deviation (R.S.D.%), was between 5.1% and 8.4% for the test compounds. The detection limits for the studied compounds were between 0.02 and 0.05pgmL(-1). The developed method offers the advantage of being simple to use, with shorter analysis time, lower cost of equipment, thermal stability of fiber, and high relative recovery in comparison to conventional methods of analysis.

Polythiophene/hexagonally ordered silica nanocomposite coating as a solid-phase microextraction fiber for the determination of polycyclic aromatic hydrocarbons in water.

A highly porous fiber coated with polythiophene/hexagonally ordered silica nanocomposite was prepared for solid-phase microextraction (SPME). The prepared nanomaterial was immobilized onto a stainless-steel wire for the fabrication of the SPME fiber. Polythiophene/hexagonally ordered silica nanocomposite fibers were used for the extraction of some polycyclic aromatic hydrocarbons from water samples. The extracted analytes were transferred to the injection port of a gas chromatograph using a laboratory-designed SPME device. The results obtained prove the ability of the polythiophene/hexagonally ordered silica material as a new fiber for the sampling of organic compounds from water samples. This behavior is due most probably to the increased surface area of the polythiophene/hexagonally ordered silica nanocomposite. A one-at-a-time optimization strategy was applied for optimizing the important extraction parameters such as extraction temperature, extraction time, ionic strength, stirring rate, and desorption temperature and time. Under the optimum conditions, the LOD of the proposed method is 0.1-3 pg/mL for analysis of polycyclic aromatic hydrocarbons from aqueous samples, and the calibration graphs were linear in a concentration range of 0.001-20 ng/mL (R(2) > 0.990) for most of the polycyclic aromatic hydrocarbons. The single fiber repeatability and fiber-to-fiber reproducibility were less than 8.6 and 19.1% (n = 5), respectively.

Periodic mesoporous organosilica with ionic liquid framework as a novel fiber coating for headspace solid-phase microextraction of polycyclic aromatic hydrocarbons.

Periodic mesoporous organosilica based on alkylimidazolium ionic liquid (PMO-IL) was prepared and used as a highly porous fiber coating material for solid-phase microextraction (SPME). The prepared nanomaterial was immobilized onto a stainless steel wire for fabrication of the SPME fiber. The fiber was evaluated for the extraction of some polycyclic aromatic hydrocarbons (PAHs) from aqueous sample solutions in combination with gas chromatography-mass spectrometry (GC-MS). A one at-the-time optimization strategy was applied for optimizing the important extraction parameters such as extraction temperature, extraction time, ionic strength, stirring rate, and desorption temperature and time. In optimum conditions, the repeatability for one fiber (n=3), expressed as relative standard deviation (R.S.D.%), was between 4.3% and 9.7% for the test compounds. The detection limits for the studied compounds were between 4 and 9 pg mL(-1). The developed method offers the advantage of being simple to use, with shorter analysis time, lower cost of equipment, thermal stability of fiber and high relative recovery in comparison to conventional methods of analysis.

Analysis of volatile oil composition of Citrus aurantium L. by microwave-assisted extraction coupled to headspace solid-phase microextraction with nanoporous based fibers.

Nanoporous silica was prepared and functionalized with amino propyl-triethoxysilane to be used as a highly porous fiber-coating material for solid-phase microextraction (SPME). The prepared nanomaterials were immobilized onto a stainless steel wire for fabrication of the SPME fiber. The proposed fiber was evaluated for the extraction of volatile component of Citrus aurantium L. leaves. A homemade microwave-assisted extraction followed by headspace (HS) solid-phase apparatus was used for the extraction of volatile components. For optimization of factors affecting the extraction efficiency of the volatile compounds, a simplex optimization method was used. The repeatability for one fiber (n = 4), expressed as RSD, was between 3.1 and 8.6% and the reproducibility for five prepared fibers was between 10.1 and 14.9% for the test compounds. Using microwave-assisted distillation HS-SPME followed by GC-MS, 53 compounds were separated and identified in C. aurantium L., which mainly included limonene (62.0%), linalool (7.47%), trans-ß-Ocimene (3.47%), and caryophyllene (2.05%). In comparison to a hydrodistillation method, the proposed technique could equally monitor almost all the components of the sample, in an easier way, which was rapid and required a much lower amount of sample.

Microwave distillation followed by headspace single drop microextraction coupled to gas chromatography-mass spectrometry (GC-MS) for fast analysis of volatile components of Echinophora platyloba DC.

To avoid the traditional and time consuming hydrodistillation, the analyses of volatile components in aerial parts of Echinophora platyloba DC was carried out by a simple microwave distillation followed by headspace single drop microextraction (MD-HS-SDME) coupled to gas chromatography-mass spectrometry (GC-MS). The headspace volatile compounds were collected after irradiation using a single drop of n-heptadecan. The extraction conditions were optimised using the relative peak areas as index. The chemical composition of the MD-HS-SDME extracts was confirmed according to their retention indexes and mass spectra. Fifty-three components were extracted and identified by using the MD-HS-SDME method. E-ß-ocimene (53.81%), R-D-decalactone (12.75%), α-pinene (6.43%), n-heptanol (6.27%), ß-phellanderne (2.70%) and linalool (1.89%) were the major constituents.

Rapid analysis of volatile components from Teucrium polium L. by nanoporous silica-polyaniline solid phase microextraction fibre.

INTRODUCTION: The development of simple, rapid and solvent-free methods for the analysis of essential oils is highly desirable. Microwave-assisted headspace solid-phase microextraction (MA-HS-SPME) is a new sampling and concentration technique for the extraction of volatile components in medicinal plants. The main advantages of this method are the reduction of extraction time and of organic solvent. OBJECTIVE: A highly porous Santa Barbara amorphous (SBA-15)/polyaniline material was prepared in order to produce a SPME fibre. The proposed fibre was evaluated for the extraction of the volatile component of Teucrium polium L. METHODOLOGY: A homemade MA-HS-SPME apparatus was used for the extraction of volatile components. Highly porous SBA-15/polyaniline materials were prepared for SPME. The prepared nanomaterial was immobilized onto a stainless steel wire for fabrication of the SPME fibre. RESULTS: The SBA-15/polyaniline nanonporous fibre could adsorb volatile components of T. polium efficiently. In comparison with a HD method, the proposed technique could equally monitor almost all the components of the sample, but in an easier way that was rapid and required a much lower amount of sample. CONCLUSION: The experimental results showed that the nanoporous fibre was suitable for the semi-quantitative study of the composition of essential oils in plant materials and monitoring the variations in the volatile components of the plants.

Inside needle capillary adsorption trap device for headspace solid-phase dynamic extraction based on polyaniline/hexagonally ordered silica nanocomposite.

Highly porous polyaniline/hexagonally ordered silica sorbent was used for fabrication of the inside needle capillary adsorption trap (INCAT) device. Polyaniline/SBA-15 nanocomposite was synthesized via chemical polymerization technique. The fabricated INCAT device was evaluated to the extraction of some polycyclic aromatic hydrocarbons (PAHs) from aqueous sample solutions in combination with gas chromatography (GC)-mass spectrometry (MS). A one at-the-time optimization strategy was applied for optimizing the important extraction parameters such as extraction temperature, extraction time, ionic strength, sampling flow rate, desorption time, and desorption temperature. In optimum conditions (extraction temperature 55 °C, extraction time 20 min, ionic strength 20% (w/v), flow rate 4.5 mL min(-1), desorption temperature 270 °C, desorption time 3 min) the repeatability for one INCAT device (n = 4), expressed as relative standard deviation, was between 4.2 and 10.2% for the tested compounds. The quantitation limits for the studied compounds were between 1 and 5 pg mL(-1). The developed method was successfully applied to spring water sample which was spiked with PAHs with the relative recovery percentages of 87.3-109.1%. The developed method offers the advantage of being simple to use, with shorter analysis times, lower cost of equipment, and thermal stability.