Sorbent For Thin Film Microextraction Research Articles

Bacteria-templated ZIF-8 embedded in polyacrylonitrile nanofibers as a novel sorbent for thin film microextraction of benzoylurea insecticides

In the present work, the rod-like ZIF-8 (ZIF8@E coli) was prepared by fast, easy and environmentally friendly method of biomimetic mineralization with Escherichia coli bacteria as a bio-template and was exploited for the first time in the microextraction. In this regard, electrospun nanofiber mats of polyacrylonitrile (PAN) and ZIF8@E coli were prepared by electrospinning method and used as a new sorbent for thin film microextraction (TFME) of benzoylurea insecticides such as Hexaflumuron and Teflubenzuron as model analytes. The PAN/ZIF8@E coli nanocomposite was characterized using electron scanning microscopy and various spectroscopy techniques. Factors affecting the proposed extraction method were screened and optimized using the experiment design strategy. Then, the model analytes were measured by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detector after microextraction. Satisfactory figures of merit were obtained for suggested TFME-HPLC-UV under optimum conditions. The suitable linearity varied in the range of 0.5–200 μg L−1 with R2 greater than 0.9968. The limit of detections for Hexaflumuron and Teflubenzuron were 0.12 and 0.15 μg L−1, respectively. The application of the method in the real sample was investigated by analyzing the selected analytes in environmental water and food samples. The spiking recovery of the selected analytes varied in the range of 93.0–109.8 % (RSD≤7.68). The results confirm the efficient application of this new sorbent in TFME approach. Considering the high availability, ease of production, and environmental friendliness of bacteria along with the significant improvement of metal-organic framework (MOF) growth efficiency, biomimetic mineralization is expected to be efficient method for the synthesis of ordered MOFs for use in extraction fields.

Application of electrospun composite nanofibers as an efficient sorbent for extraction of pesticides from food samples

Herein, the composite of polylactic acid (PLA)/ Iron-based metal-organic framework (r-MIL-88A)/ Cellulose electrospun nanofibers was fabricated; and then, applied as a novel sorbent for thin-film micro-extraction (TFME) of four selected pesticides followed by GC-FID analysis. From the evaluation of scanning electron microscopy, Fourier transform infrared spectroscopy energy dispersive X-ray spectroscopy and X-ray diffraction, the successful fabrication of composite nanaofibers was approved. The presence of r-MIL-88A/Cellulose with large surface area and plenty of OH-functional groups results in improving PLA extraction efficiency. The effect of various main parameters on extraction efficiency was evaluated. The LODs (based on S/N = 3) were in the range of 1.0 to 1.5 ng mL−1. Intra-day and inter-day relative standard deviations (RSDs) were in the range of 4.8% - 5.6% and 5.2%-6.4%, respectively. In addition, the fiber to fiber relative standard deviations were observed in the range of 5.2%–12.3%. By using the optimized factors, acceptable linearity ranges were obtained in the range of 3.0-1900.0 ng mL−1 for metribuzin and ethofumasate, and 5.0-2000.0 for atrazine and ametryn (R2 = 0.9913-0.9967). The developed method was investigated in fruit juice, vegetables, milk and honey samples, and recoveries (79.3-95.6%) indicate that the PLA/r-MIL-88A/Cellulose can be a prominent composite film for the extraction of the target analytes in various samples.

In-situ formation of Zn-Al layered double oxides on electrochemically anodized nanoporous aluminum film as sorbent for chlorophenols extraction from water and wastewater followed by determination using HPLC.

Herein, we present a simple, cost-effective, and robust strategy for the in-situ preparation of Zn-Al layered double oxides-anodized aluminum thin film via a facile hydrothermal method, followed by calcination treatment of the Zn-Al layered double hydroxide in the air atmosphere. The in-situ prepared Zn-Al layered double oxide-anodized aluminum film was implemented as sorbent for thin film microextraction of four selected chlorophenols (4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol), followed by high-performance liquid chromatography-ultraviolet detection. The different variables of the thin film microextraction were screened via Plackett-Burman design and then optimized through Box-Behnken design. Under the optimum condition, the method showed good linear ranges (0.2-200 μg/L) with the coefficient of determinations higher than 0.9938. The calculated limit of detections were between 0.07 and 0.56μg/L. Relative standard deviations of the method for determination of the analytes at 5μg/L concentration level (n=3) were ranged from 3.5 to 3.9% (as interday). The enrichment factors were between 39 and 58. This extraction method was demonstrated to be fast, efficient, and convenient. To study the capability of the developed method for real sample analysis, tap, well, river, and two types of wastewater samples were satisfactorily analyzed.

Nanocrystalline cellulose as a biotemplate for preparation of porous titania thin film as a sorbent for thin film microextraction of ketorolac, meloxicam, diclofenac and mefenamic acid

The present study included the procedure of preparing porous titania thin film using a direct nanocrystalline cellulose templating (NCC) as a bio-template. The microextraction applicability of the porous film was investigated by thin film microextraction (TFME) of the nonsteroidal anti-inflammatory drugs (NSAIDs) including ketorolac, meloxicam, diclofenac and mefenamic acid from different types of urine sample. The extracted NSAIDs were analyzed by HPLC-UV. Under optimum conditions, the calibration curves were linear within the range of 1.0–500 µg L−1 (2.0–200 µg L−1 for ketorolac, 2.0–500 µg L−1 for meloxicam, 1.0–200 µg L−1 for diclofenac and 1.0–200 µg L−1 for mefenamic acid). The limit of detection was found to be between 0.2 and 0.5 µg L−1. The calculated intra- and inter-day relative standard deviations RSDs% (n = 3) at concentration level of 10 µg L−1 were less than 6.3% and 6.0%, respectively. Finally, the method was successfully applied to determine selected NSAIDs in urine samples from different human individuals.

Woven cotton yarn-graphene oxide-layered double hydroxide composite as a sorbent for thin film microextraction of nonsteroidal anti-inflammatory drugs followed by quantitation through high performance liquid chromatography

The applicability of a highly flexible and natural cotton yarn-graphene oxide-layered double hydroxide composite (CY-GO-LDH) was introduced for the extraction of the targets in the current study. For increasing the contact area of the analytes and the prepared sorbent, the green substrate was woven and employed as the substrate for the construction of GO layers. It was proved that the prepared CY-GO-LDH film is a reliable sorbent for thin film microextraction (TFME) of the nonsteroidal anti-inflammatory drugs (NSAIDs) including acetylsalicylic acid, naproxen, diclofenac, ibuprofen and mefenamic acid in human urine and plasma. Extraction factors were optimized using multivariate optimization strategy. High adherence of GO-LDH to the natural substrate made this technique more robust for routine analysis. There are two consecutive steps to optimize the parameters influencing the extraction of analytes; First, a Plackett–Burman Design (PBD) was utilized to screen the significant factors. Second, the selected factors were optimized utilizing the Box-Behnken Design (BBD). The extracted NSAIDs were analyzed by HPLC-UV. Under the obtained optimum condition, the linearity of the method was 0.2–200 μg L−1. Limits of detection, limits of quantification and intra-day as well as inter-day RSDs were lower than 0.25 μg L−1, 0.72 μg L−1 and 6.1%, respectively. The method was successfully used to determine NSAIDs in different human biological fluids.

Preparation of a nano-biocomposite film based on halloysite-chitosan as the sorbent for thin film microextraction

This work introduced an environmentally friendly sorbent based on halloysite-chitosan nano-biocomposite for thin film microextraction (TFME). Chitosan as a biodegradable and biocompatible polymer was used to prepare thin film sorbent. To improve the mechanical and chemical resistance of the film and increasing the adsorption efficiency, halloysite nanotubes were combined with the chitosan to prepare the thin film sorbent. The film was used for TFME of 17α-ethynylestradiol followed by high-performance liquid chromatography-fluorescence detection. Effective parameters such as the amount of chitosan and halloysite, ionic strength of sample solution, type and volume of desorption solvent, desorption and extraction times were optimized. The linear dynamic range of the method was in the range of 1.0–50.0 μg L−1. The detection limit and relative standard deviation of the method were 0.4 μg L−1 and 9%, respectively. The method was validated for the TFME of 17α-ethynylestradiol in river water, wastewater, and tap water samples, and recoveries were found to be in the range of 67–106%.

Histamine functionalized magnetic nanoparticles (HIS-MNP) as a sorbent for thin film microextraction of endocrine disrupting compounds in aqueous samples and determination by high performance liquid chromatography-fluorescence detection

This paper describes the development of a new method in which histamine-functionalized magnetic nanoparticles (HIS-MNP) are used as the extraction phase associated with thin-film microextraction and a 96-well plate system. This approach was applied to the determination of estrone, estriol, 17-β-estradiol, 17α-ethynylestradiol, 4-octylphenol and 4-nonylphenol in aqueous samples by HPLC-FLD. Extraction and liquid desorption steps were optimized employing multivariate and univariate procedures. The optimum extraction conditions were 50 min of extraction time, no salt addition and sample pH 5. Liquid desorption was carried out for 30 min with 300 μL of acetonitrile:methanol (50:50 v/v). The quantification limits varied between 0.5 and 20 μg L−1. The method showed recovery values between 82 and 120%, and relative standard deviations varied from 0.1 to 13.6%.

Poly m-aminophenol/ nylon 6/graphene oxide electrospun nanofiber as an efficient sorbent for thin film microextraction of phthalate esters in water and milk solutions preserved in baby bottle

In this paper, poly m-aminophenol/nylon 6/graphene oxide (PmAP/N6/GO) electrospun nanofiber was fabricated and applied as an efficient sorbent for thin film microextraction (TFME) of phthalate esters (PAEs). The porosity, morphology, wettability, solvent stability and chemical structure of the prepared nanofiber were evaluated. The prepared PmAP/N6/GO nanofiber film exhibited some prominent advantages such as large surface area, porous fibrous structure, high stability, good hydrophilicity and excellent extraction efficiency. Afterward, thin film microextraction-gas chromatography-mass spectroscopy (TFME-GC–MS) method was developed for the quantitative analysis of PAEs, and the effective parameters on the extraction performance were investigated systematically. At the optimal operating conditions, the large linearity range (0.5–250 ng mL−1) with excellent correlation coefficient (<0.998) had been acquired for this method. Moreover, low limits of detection (LODs) (0.1–0.15 ng mL−1) exhibited the satisfactory sensitivity of the proposed method. Finally, the TFME-GC–MS method was successfully utilized for the measurement of PAEs in milk solutions and drinking water preserved in baby bottle with satisfactory relative recoveries (RRs) (88–101%) and relative standard deviations (RSDs) lower than 8.0% (n = 3). Totally, a simple, rapid, sensitive and highly efficient method was introduced to analyze trace PAEs in complex samples.

Acetone-activated polyimide electrospun nanofiber membrane for thin-film microextraction and thermal desorption-gas chromatography–mass spectrometric analysis of phenols in environmental water

In this work, a polyimide nanofiber membrane was electrospun and applied as sorbent for thin film microextraction (TFME). After TFME of phenols in water samples, direct thermal desorption of the sorbent at 300°C followed by gas chromatography-mass spectrometric (TD–GC–MS) analysis was carried out. The extraction efficiency of TFME was enhanced by 6–12 times for phenols after activation with acetone. The positive effect of acetone activation was correlated to the increased hydrophilicity of the membrane. Extraction parameters, including mass of nanofiber membrane, pH value, NaCl concentration and extraction time, were optimized. Under optimal conditions, the LODs and LOQs for analysis of phenols in spiked purified water were 0.0006–0.008 and 0.002–0.025μgL−1, respectively. The linearity range was more than two orders of magnitude (R>0.99). The RSDs of intra-batch and inter-batch were 4.3–7.4% and 2.7–10.6% (n=3). Finally the method was applied to real samples, including tap water, sea water, and waste water. These results indicate that the polyimide nanofiber membrane is a promising candidate as TFME sorbent for determination of polar analytes in water samples coupled with TD–GC–MS.

Electrospun polystyrene/oxidized carbon nanotubes film as both sorbent for thin film microextraction and matrix for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

In the current study, polystyrene/oxidized carbon nanotubes (PS/OCNTs) film was prepared and applied as both an adsorbent of thin film microextraction (TFME) and matrix for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF–MS) for the first time. The uniform size of PS/OCNTs film with OCNTs evenly and firmly immobilized in PS was obtained by electrospinning. And a novel TFME device was developed using the prepared PS/OCNTs film to enrich benzo[a]pyrene (BaP) from water, and also BaP and 1-hydroxypyrene (1-OHP) from urine sample. Then the extracted analytes on the PS/OCNTs film were directly applied to MALDI–MS analysis with PS/OCNTs film as the MALDI matrix. Our results show that PS/OCNTs film is a good TFME adsorbent toward the analytes and an excellent matrix for the sensitive determination of BaP and 1-OHP using MALDI–TOF–MS. The employment of PS/OCNTs as the matrix for MALDI can effectively avoid the large variation of signal intensity normally resulting from heterogeneous distribution of the adsorbed analyte on matrix layer, which therefore significantly improve spot-to-spot reproducibility. The introduction of PS in the film can prevent OCNTs from flying out of MALDI plate to damage the equipment. In addition, PS/OCNTs film also largely extended the duration of ion signal of target analyte compared to OCNTs matrix. The developed method was further successfully used to quantitatively determine BaP in environmental water and 1-OHP in urine samples. The results show that BaP and 1-OHP could be easily detected at concentrations of 50pgmL−1 and 500pgmL−1, respectively, indicating the high detection sensitivity of this method. For BaP analysis, the linear range was 0.1–20ngmL−1 with a correlation coefficient of 0.9970 and the recoveries were in the range of 81.3 to 123.4% with the RSD≤8.5% (n=3); for urinary 1-OHP analysis, the linear range was 0.5–20ngmL−1 with a correlation coefficient of 0.9937 and the recoveries were in the range of 79.2 to 103.4% with the RSD≤7.6% (n=3). Taken together, the developed method provides a simple, rapid, cost-effective and high-throughput approach for the analysis of BaP in environmental water and endogenous 1-OHP in urine samples.