Kapok fiber-supported liquid extraction for convenient oil samples preparations: A feasibility and proof-of-concept study

Automated kapok fiber-based pipette-tip solid-phase extraction coupled with liquid chromatography-tandem mass spectrometry for rapid and sensitive analysis of tyrosine kinase inhibitors in plasma

This study delineates the development of a novel automated pipette-tip solid-phase extraction (SPE) methodology, employing kapok fiber as a naturally efficient and cost-effective adsorbent for the selective extraction of eleven tyrosine kinase inhibitors (TKIs) from plasma. The uniqueness of this method lies in its assembly, where kapok fibers are ingeniously wrapped around a stainless-steel spring within the pipette tip, ensuring an obstruction-free central space for effortless solution aspiration and dispensation. This design significantly minimizes backpressure, enhancing operational efficiency and ensuring compatibility with pipettors, including the implementation of an electric pipettor to streamline the sample preparation process and facilitate automation. The method's analytical performance, rigorously validated through liquid chromatography-tandem mass spectrometry, exhibits outstanding linearity in ranges of 0.1/0.5-200 ng mL-1 (R² > 0.993), commendable accuracy (86.3%-114.8%), and consistent precision (3.4-11.3%), alongside remarkably low detection limits that span from 0.024 to 0.130 ng mL-1. The assembly of kapok fiber within the pipette tip, in this unique configuration, results in a practical, cost-effective, eco-friendly, and automated pipette-tip SPE method. This innovation signifies a significant advancement in bioanalytical methodologies, offering an efficient and sustainable approach for extracting analytes from complex biological samples. This process notably enhances both the sensitivity and selectivity of subsequent instrumental analyses.

Conveniently monitoring aldehyde changes in heated edible oils using miniaturized kapok fiber-supported liquid-phase extraction/in-situ derivatization coupled with liquid chromatography-tandem mass spectrometry

Heating edible oils generates aldehydes, potentially leading to adverse health effects, making their analysis essential for quality control. This study presents a convenient miniaturized kapok fiber-supported liquid-phase extraction/in-situ derivatization method for the simultaneous extraction and derivatization of aldehydes in oils. The method involves placing 150 mg oil into a 1 mL pipette tip packed with 25 mg kapok fiber, adding 150 μL ACN with 1.5 mg mL-1 DNPH, and post 30-minute static extraction, retrieving the extractant with a pipettor for liquid chromatography-tandem mass spectrometry analysis. By optimizing critical parameters through a Box-Behnken design, the method exhibits good linearity (1-500 ng g-1, R2 ≥ 0.991), low detection limits (0.2-1.0 ng g-1), excellent accuracy (95.3-107.1%) and high precisions (relative standard deviation < 7.9%). This method simplifies sample preparation processes, cuts solvent use, and facilitates automation. It effectively identifies ten aldehyde variations in six heated oils, displaying distinct profiles consistent with prior research.

Polyaniline-coated kapok fibers for convenient in-syringe solid-phase microextraction and determination of organochlorine and pyrethroid pesticide residues in aqueous samples

Pesticides used in agriculture have low polarity and a tendency to accumulate in fatty tissues, posing potential risks to human health. Effective pre-treatment is crucial due to complex sample matrices and low concentrations of pesticide residues typically encountered in instrument analysis. In this study, polyaniline-coated kapok fiber (PANI-KF) was synthesized successfully using in-situ oxidative polymerization for use as sorbents in in-syringe SPME of pyrethroid pesticides (PYRs) and organochlorine pesticides (OCPs) from aqueous samples. Coating the natural KF with PANI maintained the hollow microtubular structure and fiber morphology while significantly enhancing the extraction efficiency. The extraction process was easily conducted by simply pulling and pushing the syringe plunger. The entire extraction process, utilizing 3 mg of PANI-KF, could be completed in approximately 3 min. Density functional theory results indicated that the adsorption mechanism of PANI-KF towards OCPs and PYRs mainly involved van der Waals interactions, π-π interactions, and weak hydrogen bonding interactions. With the coupling of gas chromatography-mass spectrometry, a quantification method was established that exhibited good linearities (R2 > 0.990), and relative recoveries (87.2-108.5 %). The limits of detection ranged from 0.4 to 2.0 ng mL-1 and the matrix effects were negligible (-12.3-16.4 %). The validated in-syringe SPME-GC-MS method was successfully applied to determine pesticide residues in fruit juices, oral liquids and herbal extract granules with satisfactory accuracy and precision. PANI-KF exhibits remarkable promise as a sorbent for the extraction and enrichment of pesticide residues in aqueous samples, thereby contributing to the advancement of pesticide residue determination methodologies.

Magnetic phytic acid-modified kapok fiber biochar as a novel sorbent for magnetic solid-phase extraction of antidepressants in biofluids

BACKGROUND

Therapeutic drug monitoring (TDM) of antidepressants is essential for monitoring patient medication to avoid drug toxicity, complications, or nonadherence. Chromatographic techniques with high sensitivity and reproducibility are the main detection method for antidepressants. Effective pretreatment of biological sample processes is necessary prior to instrumental analysis. Magnetic solid-phase extraction (MSPE) has received much attention for its advantages of simple operation, rapidity, cost-effectiveness and low organic solvent consumption. Therefore, the development of a suitable and green magnetic sorbent for the detection of antidepressants in plasma and urine is apparently necessary. (88) RESULTS: A magnetic phytic acid-modified kapok fiber biochar sorbent (Fe3O4/PAKFBC) was successfully synthesized by pyrolytic impregnation and physical milling methods. Fe3O4/PAKFBC exhibited a large specific surface area (214 m2 g-1) and a rich pore structure (5-10 nm). The extraction equilibrium, using 10 mg Fe3O4/PAKFBC, can be completed in about 1 min. The density functional theory (DFT) results showed that the adsorption mechanism of Fe3O4/PAKFBC on the six antidepressants mainly included electrostatic interactions, van der Waals interactions, π-π interactions and weak hydrogen bonding. Examination using the greenness assessment tools showed that the developed method exhibited excellent greenness. By combining with liquid chromatography-ultraviolet (LC-UV), a quantitative method with good linearity (R2 > 0.993) and relative recoveries (92.4-107.7%) and negligible matrix effect (-11.5-6.0%) was developed. The Fe3O4/PAKFBC successfully detected six antidepressants in plasma and urine samples, requiring no pH adjustment with buffer salts. (142) SIGNIFICANCE: The environmental sustainability of the proposed methods was affirmed by six greenness evaluation tools, all indicating exceptional eco-friendliness. The Fe3O4/PAKFBC demonstrated outstanding greenness in both its creation and analytical application, proving highly effective in real sample applications and showcasing potential for broader use. This study contributes to a deeper and broader understanding of the microscopic adsorption mechanism, which can help in the optimization and development of more green sorbents. (69).

In-pipette-tip kapok fiber-supported liquid extraction/in-situ derivatization coupled with high-performance liquid chromatography for conveniently determining three furfurals

This study presents an in-pipette-tip kapok fiber-supported liquid extraction/in-situ derivatization (in-pipette-tip KF-SLE-ISD) method for simultaneous enrichment and derivatization of furfurals. Briefly, 3 mg of natural kapok fiber, which was loaded in an assembled pipette-tip, was used to support 12.5 μL of extractant (ethyl acetate/toluene, 75:25, v/v) containing 10 mM 2,4-dinitrophenylhydrazine. The in-pipette-tip KF-SLE-ISD procedure was conveniently conducted by aspirating/releasing 1 mL of sample solution 10 cycles, allowing simultaneous extraction and derivatization of furfurals. Then, 100 μL of acetonitrile was aspirated/released 5 cycles for elution, 10 μL of which was directly analyzed by high-performance liquid chromatography. The limits of quantitation were in ranges of 0.10-0.45 μg/mL. The method showed satisfied linearity (R² > 0.99), precision (RSD < 8.53%) and relative recovery (90.34-114.71%), which was successfully applied to determine furfurals in various samples (e.g., honeys, juices and glucose injections). The proposed method has the merits of effectiveness, simplicity, low cost, wide availability and ease of automation.

A fully green sample preparation method for synthetic antioxidants determination in edible oils based on natural feather fiber-supported liquid extraction

The current study proposed a novel feather fiber-supported liquid extraction (FF-SLE) method for extracting analytes from oil samples. The natural feather fibers were used as the oil support material and directly loaded in the plastic tube of a disposable syringe to construct the low-cost extraction device (∼0.5 CNY). The edible oil without any pretreatment including dilution was added directly to the extraction device, followed by the addition of the green extraction solvent of ethanol. As an example, the proposed method was applied to extract nine synthetic antioxidants from edible oils. The optimized extraction conditions for processing 0.5 g of oil were obtained when the syringe dimension was 5 mL, the extraction solvent was 0.5 mL of ethanol, the amount of feather fibers was 200 mg of duck feather fibers and the static extraction time was 10 min. The applications to seven kinds of feathers and seven kinds of edible oils all indicated the excellent oil removal efficiencies (>98.0%). Combined with high-performance liquid chromatography-ultraviolet, a quantification method was validated with satisfied linearity (R²≥0.994), accuracy (95.8-114.6%) and precision (≤8.3%) with the limits of detection ranging from 50 to 100 ng/g. The proposed FF-SLE method was simple, effective, convenient, low-cost, green and environmental-friendly for the extraction of analytes from oil samples prior to instrument analysis.