Polymeric ionic liquid-based portable tip microextraction device for on-site sample preparation of water samples

Automated and semi-automated packed sorbent solid phase (micro) extraction methods for extraction of organic and inorganic pollutants

In this study, the packed sorbent solid phase (micro) extraction methods from manual to automated modes are reviewed. The automatic methods have several remarkable advantages such as high sample throughput, reproducibility, sensitivity, and extraction efficiency. These methods include solid-phase extraction, pipette tip micro-solid phase extraction, microextraction by packed sorbent, in-tip solid phase microextraction, in-tube solid phase microextraction, lab-on-a-chip, and lab-on-a-valve. The recent application of these methods for the extraction of organic and inorganic compounds are discussed. Also, the combination of novel technologies (3D printing and robotic platforms) with the (semi)automated methods are investigated as the future trend.

Electrokinetic Extraction of Doxorubicin from Biological Fluids by Polymer Inclusion Membrane Sampling Probe

A polymer inclusion membrane (PIM) based sampling probe was developed for electrokinetic extraction of drugs from biological fluids. The probe was fabricated by dip-coating a nonconductive glass capillary tube in a homogeneous PIM solution for three cycles. The PIM solution comprised cellulose triacetate (CTA), 2-nitrophenyl octyl ether (NPOE), and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [EMIM][NTf₂] in a ratio of 5:4:2. The developed probe electrokinetically extracted doxorubicin from human plasma, human serum, and dried blood spot (DBS). The practicability and reliability of the electrokinetic extraction were evaluated by LC-MS/MS to quantify the desorption of extracted doxorubicin. Under the optimized conditions, a quantification limit of 0.2-2 ng/mL was achieved for the three biological samples. The probe was further integrated into a portable battery-powered device for safe low-voltage (36 V) electrokinetic extraction. The developed technique is envisioned to provide a more efficient analytical workflow in the laboratory.

Recent advances in micro- and nanomaterial-based adsorbents for pipette-tip solid-phase extraction

There are a lot of review papers of sample pretreatment, but the comprehensive review on pipette-tip solid-phase extraction (PT-SPE) is lacking. This review (133 references) is mainly devoted to the development of different types of micro- and nanosorbent-based PT-SPE, including silica materials, carbon materials, organic polymers, molecularly imprinted polymers, and metal-organic frameworks. Each section mainly introduces and discusses the preparation methods, advantages and limitations of adsorbents, and their applications to environmental, biological, and food samples. This review also demonstrates the advantages of PT-SPE like convenience, speed, less organic solvent, and low cost. Finally, the future application and development trend of PT-SPE are prospected.

Preparation and evaluation of various banana-based biochars together with ultra-high performance liquid chromatography-tandem mass spectrometry for determination of diverse pesticides in fruiting vegetables

Biomass, originates from plant- or animal-based materials with a huge potential to be reused. Here we report a simple, rapid and inexpensive method for preparation of modified biochars derived from the banana peel followed by their applications in pipette-tip micro solid-phase extraction (PT-µSPE). Due to the contribution of various effective parameters on modification of banana peel biochars (BPBs), Taguchi design was used to optimize activation temperature, activation repetition, treatment material and impregnation ratio. Efficiency of the prepared BPBs were studied by extraction of twelve various pesticides, as model analytes with an extended range of log P values (1.4-5.7), followed by their determination using ultra-high performance liquid chromatography-tandem mass spectrometry. After finding the most suitable BPB, the affecting parameters on the PT-µSPE performance were optimized. Accordingly, the LOD values of 0.03-10 µg L^-1, linear dynamic range of 0.1-200 µg L^-1 and a range of RSD values of 5.3-19% were obtained. Eventually, five fruiting vegetables were analyzed and screened for their possible contaminations. Among the tested pesticides, chlorpyrifos, diazinon, malathion, phosalone, propargite and thiophanate-methyl were detected in eggplant, sweet pepper, zucchini and tomato.

Highly Permeable Monolith-based Multichannel In-Tip Microextraction Apparatus for Simultaneous Field Sample Preparation of Pesticides and Heavy Metal Ions in Environmental Waters

A portable multichannel in-tip microextraction-based field sample preparation (FSP) apparatus was developed using polymer-based monoliths as an extraction phase. The construction of the FSP device is quite facile and convenient. More specifically, according to the chemical properties of studied analytes, functional-rich and high-permeability monoliths were in situ synthesized in pipet tips. After that, three tips containing the sorbents were mounted to three syringes, which were connected to a screw motor employed to drive the syringes and accurately regulate the flow rates in the adsorption and desorption stages. Because of the multifunction groups in the monoliths, the sorbents displayed satisfactory coextraction performance for pesticides (carbamates and triazoles) and heavy metal ions (Cd²⁺, Pb²⁺, and Cu²⁺) under the optimized conditions. The practicability of the proposed apparatus was demonstrated by the quick and simultaneous FSP of studied analytes in various environmental waters and combined with high-performance liquid chromatography/diode-array detection (for pesticides) and atomic absorption spectrometry (for metal ion) analysis. The results indicated that the limits of detection for the pesticides and metal ions were in the range of 0.36 to 1.2 ng/L and 0.061 to 0.40 ng/L, respectively, with ideal coefficients of determination. Furthermore, the results obtained with the constructed device were quite comparable to those obtained with the traditional laboratory extraction process, which demonstrated that the newly developed apparatus possesses the expected application in the high-throughput FSP of pesticides and heavy metal ions in water samples.

Eco-friendly and facile one-step synthesis of a three dimensional net-like magnetic mesoporous carbon derived from wastepaper as a renewable adsorbent

Millions of tons of paper and its derivatives are annually wasted without being recycled and reused. To promote the comprehensive utilization of resources and eco-friendly preparation, waste filter paper, printer paper, and napkins were chosen as carbon sources to one-step synthesize three types of three dimensional (3D) net-like magnetic mesoporous carbon (MMC) by an eco-friendly and low-cost method. These mesoporous (3.90–7.68 nm) composites have a high specific surface area (287–423 m² g⁻¹), well-developed porosity (0.24–0.74 cm³ g⁻¹) and abundant oxygen-containing functional groups. Compared to the other two composites, the adsorbent derived from filter paper showed the highest adsorption capacity towards methylene blue (MB) (q_max = 332.03 mg g⁻¹) and rhodamine B (RhB) (q_max = 389.59 mg g⁻¹) with a high adsorption rate (<5 min). According to the effect of pH value on adsorption capacity, and combining the analysis of Fourier transform infrared spectrometry and X-ray photoelectron spectroscopy, the main adsorption mechanisms can be summarized as hydrogen bonds, electrostatic interactions, and π–π interaction. Besides, the occurrence of redox reactions between Fe²⁺/Fe⁰ and dye cannot be ignored. Finally, experiments on reusability were performed. They showed that the 3D net-like MMC could be easily regenerated and still maintained a removal efficiency of above 80% for RhB and 90% for MB after five cycles.

Millions of tons of paper and its derivatives are annually wasted without being recycled and reused.