Modified Diatomaceous Earth in Heparin Recovery from Porcine Intestinal Mucosa.

Heparin, a highly sulfated glycosaminoglycan, is a naturally occurring anticoagulant that plays a vital role in various physiological processes. The remarkable structural complexity of heparin, consisting of repeating disaccharide units, makes it a crucial molecule for the development of commercial drugs in the pharmaceutical industry. Over the past few decades, significant progress has been made in the development of cost-effective adsorbents specifically designed for the adsorption of heparin from porcine intestinal mucosa. This advancement has been driven by the need for efficient and scalable methods to extract heparin from natural sources. In this study, we investigated the use of cationic ammonium-functionalized diatomaceous earth, featuring enhanced porosity, larger surface area, and higher thermal stability, to maximize the isolated heparin recovery. Our results showed that the higher cationic density and less bulky quaternary modified diatomaceous earth (QDADE) could adsorb up to 16.3 mg·g-1 (31%) of heparin from the real mucosa samples. Additionally, we explored the conditions of the adsorbent surface for recovery of the heparin molecule and optimized various factors, such as temperature and pH, to optimize the heparin uptake. This is the introductory account of the implementation of modified diatomaceous earth with quaternary amines for heparin capture.

κ-Carrageenan/triazin-based covalent organic framework bionanocomposite: Preparation, characterization, and its application in fast removing of BB41 dye from aqueous solution.

A novel and high efficient adsorbent was prepared based on an environmentally friendly substrate, κ-carrageenan, and a triazine-based covalent organic framework as a co-adsorbent component. Combining these two precursors leads to an effective nanocomposite for removing Basic blue 41 dye from aqueous media. After confirm the structural of prepared composite by various analysis, the adsorption properties were investigated. The optimum conditions were obtained in: pH: 7, temperature: 25 °C and contact time: 210 min; and adsorbent dosage of 10 mg. According to the isotherms study, the basic blue 41 dye adsorption was matched to the Longmuir model with single-layer mechanism. The kinetic of adsorption was studied and fitted with pseudo-second order model with R2 = 0.971. From the results the maximum adsorption capacity of 833 mg/g was obtained in 15 min and the reusability tests showed 24% decrease in yield after three cycles.

High efficient solid-phase microextraction based on a covalent organic framework for determination of trifluralin and chlorpyrifos in water and food samples by GC-CD-IMS.

Novel porous covalent organic framework (COF) based on condensation reaction between cyanuric chloride, 4,4'-ethylendianiline, and 3,4,9,10-perylenetetracarboxylic dianhydride was synthesized via sealed tube condition. The results COF was used as a new adsorbent for solid-phase microextraction (SPME) for extracting trifluralin and chlorpyrifos from vegetables, fruit samples, and wastewater. Gas chromatograph with a corona discharge-ion mobility spectrometer as the detector was also used for analyzing the target analytes. Some parameters that affected the extraction, such as stirring rate, time and temperature of extraction and pH were investigated, exhaustively. The detection limits were 0.13, and 0.15 µg/L and the linear ranges of 0.45-20 and 0.50-25 µg/L with a linearity coefficient of 0.9965 and 0.9987 were also obtained for trifluralin and chlorpyrifos, respectively. The method was applied successfully to analyze some real samples of cucumber, carrot, grape, and agriculture wastewater, and the results showed a relative recovery in the range of 87% to 110%.

Ultrasonic Piezoelectric Nebulization of Propoxur for the Determination by Corona Discharge Ionization Ion Mobility Spectrometry.

Propoxur insecticide as a thermally unstable compound (decomposed at its boiling point) could not be analyzed by traditional sample introduction systems based on the thermal desorption. In this study, an ultrasonic piezoelectric nebulizing injection port was applied for evaporating this compound prior to its determination by corona discharge ionization ion mobility spectrometry (CD-IMS). The target analyte was extracted from different water samples by using the extraction method of dispersive liquid-liquid microextraction. Methanol and trichloromethane were utilized as the disperser and extraction solvents, respectively. The effective variables included the volume of the disperser and the extraction solvents, the pH, and the centrifugation time were studied by a Fractional Factorial Design to identify the important parameter(s) and their interaction. To that end, a Central Composite Design was performed to achieve optimum levels of each effective parameter. The results showed that the optimum conditions were 78 µL of the extraction solvent, and 1.2 mL for the disperser solvent; centrifugation time was 1 min at 1010g, and finally pH 7. A detection limit of 2.1 µg L-1, a linear range of 2.5 - 80 µg L-1, and a relative standard deviation of 7% were obtained. Different water samples were analyzed by the proposed technique, and the propoxur amounts were successfully determined. The obtained results revealed satisfactory relative recovery values of between 91 and 105%.