Chromium-based metal organic framework for pipette tip micro-solid phase extraction: an effective approach for determination of methyl and propyl parabens in wastewater and shampoo samples

Porous Polymer Sorbents in Micro Solid Phase Extraction: Applications, Advantages, and Challenges

In recent years, porous polymers have gained significant attention for their application as powerful and selective sorbents in micro solid phase extraction (µSPE). In this review we explore the preparation and utilization of various porous polymer sorbents, highlighting their impact on enhancing µSPE techniques. Molecularly imprinted polymers (MIPs), graphene oxide-modified frameworks, and zeolitic imidazole frameworks (ZIFs) are among the innovative materials discussed. These innovative materials have significantly improved µSPE methods, offering enhanced extraction efficiencies, superior selectivity, and reduced solvent consumption, all of which align with the principles of green chemistry. Key findings of this review include the demonstration that MIPs exhibit excellent target specificity, making them ideal for complex matrices, while graphene oxide frameworks and ZIFs provide increased surface area and stability for diverse analytical applications. Despite these advancements, challenges remain, particularly the high cost of certain innovative materials, limited reusability, and the absence of automation in µSPE workflows. Furthermore, controlling the precise synthesis and functionalization of these sorbents continues to be a limiting factor. To address these issues, future research should focus on developing cost-effectiveness methods, the use of biopolymer or sustainable feedstocks, and scalable synthesis methods; integrating automation into µSPE; and exploring new polymeric materials with enhanced properties. Additionally, novel hybrid materials that combine the strengths of multiple sorbents offer a promising direction for future exploration. We critically analyze the advantages and limitations of each sorbent type, providing a comprehensive overview of their applications in µSPE. This paper also examines the synthesis, characterization, and unique properties of these porous polymers, emphasizing their role in advancing analytical chemistry towards more efficient and environmentally friendly practices. The need for continued development of high-performance, low-cost, and sustainable sorbents is underscored to further enhance the effectiveness of µSPE techniques.

Application of a magnetically separable Zr-MOF for fast extraction of palladium before its spectrophotometric detection

In this research, a novel magnetic zirconium-based metal-organic framework (Fe3O4@SiO2@MIP-202, MMOF), was fabricated, fully characterized, and applied for the batch-mode solid phase extraction of trace amounts of Pd2+ ions from water and wastewater samples before its spectrophotometric detection. Pd2+ ions were desorbed from MMOF by nitric acid and were complexed by treating with KI solution to have a maximum absorbance at 410 nm. The synthesized MMOF composite showed a very large surface area (65 m2.g- 1), good magnetization (1.7 emu.g- 1) and a large pore volume (0.059 cm3.g- 1) with adsorption capacity of 194.5 mg of Pd2+ ions/g of the adsorbent. This nanosorbent boasts chemo-mechanical stability, high adsorption capacity due to its vast active sites, and facile recovery facilitated by its magnetic properties. Parameters affecting the extraction efficiency of the method were optimized as pH of the sample 7.4, volume of the sample 25 mL, 15 mg adsorbent, 1 mL of 0.1 M HNO3 eluent, with 10 and 15 min as the extraction and desorption times, respectively. The calibration curve was found to be linear across the 10.0-1500.0 µg.L- 1 range with a limit of detection of 1.05 µg.L- 1. The obtained extraction efficiency and enrichment were 98% and 245, respectively. The total analysis time was less than 30 min. This MMOF has never been used for the extraction of Pd2+ ions before.

MIL-68 (Ga) for the extraction of derivatized and non-derivatized parabens from healthcare products

This study was the first-ever attempt to apply MIL-68 (Ga) in developing an analytical method. The method extracts and preconcentrates some parabens from mouthwash and hydrating gel samples. The variable extraction parameters were optimized, and the figures of merit were documented. Avogadro software was used besides discussing intermolecular interactions to clarify the absorption process. ComplexGAPI software was also exploited to assess the greenness of the method. After the derivatization of the parabens using acetic anhydride in the presence of sodium carbonate, sodium chloride was added to the solution and vortexed to dissolve. A few milligrams of MIL-68 (Ga) were added into the solution and vortexed. Centrifugation separated the analyte-loaded absorbent, which was treated with mL volume of methanol through vortexing for desorption aim. A few microliters of 1,2-dibromoethane were merged with the methanolic phase and injected into a sodium chloride solution. One microliter of the extracted phase was injected into a gas chromatograph equipped with a flame ionization detector. High enrichment factors (200-330), reasonable extraction recoveries (40-66%), wide linear ranges (265-30,000 µg L-1), and appreciable coefficients of determination (0.996-0.999) were documented. The applicability of dispersive solid phase extraction for extracting polar analytes, imposing no additional step for performing derivatization, the capability of MIL-68 (Ga) for the absorption of both derivatized and non-derivatized parabens, the use of only 10 mg absorbent, and one-pot synthesis besides no high temperature or long reaction time in the sorbent provision are the highlights of the method.

Microplastics removal from aqueous environment by metal organic frameworks

This paper provides an overview of recent research performed on the applications of metal-organic frameworks (MOFs) for microplastics (MPs) removal from aqueous environments. MPs pollution has become a major environmental concern due to its negative impacts on aquatic ecosystems and human health. Therefore, developing effective and sustainable methods for removing them from aqueous environments is crucial. In recent years, MOFs have emerged as a promising solution for this purpose due to their unique properties such as high surface area, renewability, chemical stability, and versatility. Moreover, their specific properties such as their pore size and chemical composition can be tailored to enhance their efficiency in removing MPs. It has been shown that MOFs can effectively adsorb MPs from aqueous media in the range of 70-99.9%. Besides some high price concerns, the main drawback of using MOFs is their powder form which can pose challenges due to their instability. This can be addressed by supporting MOFs on other substrates such as aerogels or foams. Meanwhile, there is a need for more research to investigate the long-term stability of MOFs in aqueous environments and developing efficient regeneration methods for their repeated use.

Determination of Free Histidine in Complex Hair Care Products with Minimum Sample Preparation Using Cation-Exchange Chromatography and Post Column Derivatization

In this communication, we describe the first analytical method for the determination of free histidine in hair care products (shampoos and conditioners). Cation-exchange chromatography combined with postcolumn derivatization and fluorimetric detection enabled the accurate (recovery: 83.5-114.8%) and precise (2.4-5.6% RSD) determination of free histidine without matrix interferences at concentration levels down to 1.5 mg kg^-1. Real commercially available samples were found to contain the amino acid at levels ranging between 70 and 535 mg kg^-1.

Synthesis of Bioactive Yttrium-Metal-Organic Framework as Efficient Nanocatalyst in Synthesis of Novel Pyrazolopyranopyrimidine Derivatives and Evaluation of Anticancer Activity

Novel Yttrium-metal-organic framework (Y-MOF) was synthesized under optimal conditions of microwave with a power of 20 W, the temperature of 30 degrees of centigrade, and time duration of 10 min. The products were characterized by SEM (morphology and size distribution), TGA (thermal stability), BET technique (surface area), and FTIR (characterization of the related group). The Yttrium-metal-organic framework (Y-MOF) synthesized in this study, after identifying and confirming the structure, was used as an efficient and recyclable catalyst in the synthesis of new pyrazolopyranopyrimidine derivatives. Following the study of the properties and applications of Y-MOF, its anticancer properties on breast cancer cells based on the MTT method were evaluated, and significant results were observed. In addition, the anticancer properties of the pyrazolopyranopyrimidine derivatives were investigated.