The potential of lignocellulosic biomass for magnetic solid phase extraction of naproxen from saliva samples.

This paper presents a study on the application of magnetic biochars derived from three distinct biomass sources: almond (AMBC), walnut (WMBC), and peanut (PMBC) shells for magnetic solid-phase extraction (MSPE) of naproxen, a non-steroidal anti-inflammatory drug, from human saliva prior to LC-MS analysis. The three magnetic biochars were synthesized and characterized through IR, XRD, SEM, and EDX analyses. This work explored the factors influencing extraction efficiency using these three bioadsorbents through experimental design. The results obtained revealed that magnetic biochar derived from almond shells demonstrated outstanding performance in terms of naproxen extraction, achieving an impressive yield of 100.2%. This remarkable efficiency was achieved by optimizing parameters, including a 12-minute extraction time, a 3.5 mL elution volume, a 10 mg adsorbent mass, and a 4-minute elution time. Consequently, this study established almond shell as a low-cost, environmentally friendly, and efficient magnetic biochar for extracting naproxen from human saliva. This superior performance was made possible due to the abundant lignocellulosic potential inherent in almond shell structures, surpassing that of the other two biochars. The combination of magnetic extraction with LC-MS demonstrates good linearity, with an R2 value equal to 0.9987. The limits of detection (LOD) and quantification (LOQ) are 0.013 and 0.047 µg L-1, respectively.

Green magnetic snail shell hydroxyapatite sorbent for reliable solid-phase extraction of pesticides from water samples.

To address sustainability issues, the green synthesis of nanomaterials has recently received considerable attention. This article addresses a novel and cost-effective adsorbent for the extraction of eight phenyl-N-methylcarbamate insecticides from water samples. We first synthesized a magnetite/hydroxyapatite nanocomposite using snail shell powder via an environmental friendly approach. The morphology and physicochemical properties of magnetic hydroxyapatite were characterized by Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. Magnetic extraction parameters were optimized using a Doehlert matrix. Under optimum conditions, the magnetic extraction coupled with a LC-MS method shows good linearity with R2 ≥ 0.9982, suitable intra- and interday precision, and limits of detection and quantification in the range of 0.052-0.093 µg/L and 0.11-0.31 µg/L, respectively. Satisfactory relative recoveries of all carbamates were achieved from fortified water samples in the range of 93.89-101.01%.

Natural Resources Exploitation in Sulfate-Resisting Portland Cement Manufacturing: Towards Quality Improvement and Reduction of Environmental Impact.

Sulfate-resisting (SR) Portland cement is commonly used in building works to improve concrete's durability against external sulfate attack. This attack is considered a very serious chemical aggression that causes damage and cracking of concrete structures. These special cements have a very particular mineralogical composition, C3A ≤ 3% and (2C3A + C4AF) ≤ 20%, which makes the cementitious matrix resistant to sulfate attack. This kind of product is very difficult to manufacture since low alumina (C3A) necessitates the use of a high kiln temperature in order to keep a sufficient liquid phase necessary to maintain the stability of the cement manufacturing process. In this context, this study aims to optimize SR Portland cement raw meals using natural materials collected from different regions in Tunisia, mainly ordinary limestone, siliceous limestone, black marl, grey marl, iron ore, and natural fluorapatite. The collected specimens were characterized by an X-ray fluorescence spectrometer in order to determine its elemental chemical composition. The optimization of the SR Portland cement raw meal combinations was done by means of a calculation tool based on the chemical composition of each used raw material and the variation of burning modules (LSF, SIM, and ALM). It has been found that natural fluorapatite integration (0%-15%) in raw mix preparation leads to the raw meals required for the SR Portland cement standard (C3A ≤ 3% et 2 C3A + C4AF ≤ 20%). Moreover, it was shown that the estimated SR raw meals ensure the cement manufacturing process stability (acceptable burning modules "LSF = 100; SIM = 3; ALM = 0.91 and sufficient liquid phase) and decrease the CO2 emissions in cement production.

Cuttlefish bone powder as an efficient solid-phase extraction sorbent of anti-SARS-CoV-2 drugs in environmental water.

Many antiviral drugs were developed to counteract coronavirus disease, 2019 (COVID-19) with severe acute respiratory syndrome. Therefore, the scientific community's efforts have focused on the detection and quantification of antiviral compounds currently being tested for COVID-19 treatment. Cuttlefish bone powder (CFBP) has been used for the first time as solid-phase extraction (SPE) sorbent for the extraction of SARS CoV-2 antiviral drugs (chloroquine, ritonavir and indomethacin) from water samples. An effective and sensitive method was developed by combining SPE and liquid chromatography- UV detection (LC-UV). An experimental design was applied for the optimization of extraction process. Experimental variables were optimized using Doehlert matrix. The developed method included 50 mg of CFBP sorbent, 20 mL of water sample at pH = 9 and 5 mL of ACN/KH2PO4 buffer solution (80:20, v/v) in the elution step. For validation of the method, selectivity, linearity precision, and sensitivity were evaluated. Extraction recovery percentage of all Sars cov-2 antivirals were above 98.2%. The detection and quantification limits were between 0.1 and 0.5 µg L-1 and 0.6 and 2 µg L-1, respectively. The current study suggested that CFBP has the application potential for the enhanced SPE of SARS CoV-2 antiviral drugs from water samples.

Structural Study of Europium Doped Gadolinium Polyphosphates LiGd(PO3)4 and Its Effect on Their Spectroscopic, Thermal, Magnetic, and Optical Properties.

Alkali metal-rare earth polyphosphates LiGd(1-x)Eux(PO3)4 (LGP:Eu3+) (where x= 0, 0.02 and 0.04) were synthesized by solid-state reaction. The Rietveld refinement showed the following cell parameters: I 2/a space group, a=9.635(3) Å, b=7.035(3) Å, c=13.191(3) Å, ß=90.082°, V= 894.214Å3, and Z=4. The similarity between RF=4.21% and RB=4.31% indicated that the realized refinement is reliable. The crystal structure consists of infinite zig-zag chains of (PO4)3- tetrahedra, linked by bridging oxygen. The acyclic structure of polyphosphates is confirmed by infrared and Raman (IR) spectroscopies. A good thermal stability up to 940°C and paramagnetic behavior of these compounds were also proved by thermal analyses and magnetic susceptibility measurements, respectively. Excitation spectra revealed the charge transfer phenomenon between O2- and Eu3+ (CTB), the energy transfer from Gd3+ to Eu3+, and the intrinsic 4f-4f transitions of Eu3+ where the electronic transitions were also identified. Moreover, LGP:Eu3+ can emit intense reddish orange light under excitation at 394 nm. The strongest tow at 578 and 601 nm can be attributed to the transitions from excited state 5D0 to ground states 7F1 and 7F2, respectively.

Synthesis and characterization of chitosan-coated titanate nanotubes: towards a new safe nanocarrier.

In this work, we discuss for the first time the elaboration of nanohybrid materials, intended for drug delivery systems, based on titanate nanotubes (TiONts) coated with chitosan polymer (CT). Chitosan has been used to enhance the biocompatibility of hydrothermally synthesized nanotubes in biological medium as a substitute for the polyethylene glycol (PEG) that is generally used for biocompatibility. CT grafting was carried out using two different approaches; the first was made by a covalent bond using two intermediate molecules, and the second is based on electrostatic interactions between CT and TiONts. The type of elaborated bond on the surface of TiONts was proven to influence the colloidal stability of the elaborated nanohybrids, which were studied in different media. A detailed comparison between these two approaches was carried by XPS and TGA-SM techniques. Finally, an original and sensitive cytotoxicity assay consisting of the measurement of the cells' total RNA synthesis was used to prove the non-toxicity of both obtained nanohybrids.