Multiphase electroextraction of malachite green from surface water and its determination using digital imaging and chemometric tools.

This study introduces a novel method for the quantification of malachite green (MG), a pervasive cationic dye, in surface water by synergizing multiphase electroextraction (MPEE) with digital image analysis (DIA) and partial least square discriminant analysis. Aimed at addressing the limitations of conventional DIA methods in terms of quantitation limits and selectivity, this study achieves a significant breakthrough in the preconcentration of MG using magnesium silicate as a novel sorbent. Demonstrating exceptional processing efficiency, the method allows for the analysis of 10 samples within 20 min, exhibiting remarkable sensitivity and specificity (over 0.95 and 0.90, respectively) across 156 samples in both training and test sets. Notably, the method detects MG at low concentrations (0.2 µg L-1) in complex matrices, highlighting its potential for broader application in environmental monitoring. This approach not only underscores the method's cost-effectiveness and simplicity but also its precision, making it a valuable tool for the preliminary testing of MG in surface waters. This study underscores the synergy among MPEE, DIA, and chemometric tools, presenting a cost-efficient and reliable alternative for the sensitive detection of water contaminants.

Layer-by-layer assembly of PDDA/MWCNTs thin films as an efficient strategy for extraction of organic compounds from complex samples.

This article presents the assembly and characterization of poly(diallyldimethylammonium chloride)/multi-walled carbon nanotubes (PDDA/MWCNTs) thin films on borosilicate bottles using a layer-by-layer (LBL) approach. The thin films, consisting of 10 bilayers of coating materials, were thoroughly characterized using UV-VIS spectroscopy, scanning electron microscopy (SEM), and zeta potential measurements. The modified bottles were then utilized for the extraction of analytes with diverse acid-base characteristics, including drugs, illicit drugs, and pesticides, from saliva, urine, and surface water samples. The studied analytes can be adsorbed on the surface of the LBL film mainly through hydrogen bonding and/or hydrophobic interactions. Remarkably high extraction percentages of up to 92 % were achieved, accompanied by an impressive enhancement in the analytical signal of up to 12 times when the sample volume was increased from 0.7 to 10 mL. These results highlight the outstanding extraction and sorption capabilities of the developed material. Additionally, the (PDDA/MWCNTs)10 films exhibited notable resistance to extraction and desorption processes, enabling their reuse for at least 5 cycles. The straightforward and cost-effective fabrication of these sorbent materials using the LBL technique, combined with the ability to extract target compounds during sample transportation and/or storage, renders this sample preparation method a promising alternative.

An easy and robust method for the isolation of high quality RNA from coconut tissues

BACKGROUND: Coconut tissues consist of a complex network of polysaccharides, proteins, polyphenols, and lipids that can bind to nucleic acids and pose difficulty in isolation. Certainly, a vigorous method is required to isolate high quality and quantity of RNA from such tissues for the purpose of downstream experiments. In this paper, we discuss a newly developed method for the Isolation of RNA from Complex Matrices (IRCM) method from coconut tissues. RESULTS: The method is robust, cheap, and efficient for the extraction of quality RNA in high quantities from the solid endosperm of stored and fresh coconut (150 µg/g FW with A260/280 = 1.89 and 247.5 µg/g FW with A260/280 = 1.91), coconut apple (263.8 µg/g FW with A260/280 = 1.97), and coconut bud (1052.5 µg/g FW with A260/280 = 2.00). The other well established methods, such as Method of RNA Isolation from Palm (MRIP), Cetyl Trimethyl Ammonium Bromide (CTAB), TRIZOL, and RNA plant kit failed to isolate quality RNA in appreciable quantities from the coconut tissues. Furthermore, the resultant RNA performed well in the downstream experiment, that is, RT-PCR for the production and amplification of cDNA. CONCLUSIONS: From the study, we concluded that the present method will play a vital role in the extraction of high quality RNA from complex matrices in a short time.

Electrochemical treatment of penicillin, cephalosporin, and fluoroquinolone antibiotics via active chlorine: evaluation of antimicrobial activity, toxicity, matrix, and their correlation with the degradation pathways.

Antibiotics are pharmaceuticals widely consumed and frequently detected in environmental water, where they can induce toxic effects and development of resistant bacteria. Their structural variety makes the problem of antibiotics in natural water more complex. In this work, six highly used antibiotics (at 40 µmol L-1) belonging to three different classes (penicillins, cephalosporins, and fluoroquinolones) were treated using an electrochemical system with a Ti/IrO2 anode and a Zr cathode in the presence of NaCl (0.05 µmol L-1). The attack of electrogenerated active chlorine was found to be the main degradation route. After only 20 min of treatment, the process decreased more than 90% of the initial concentration of antibiotics, following the degradation order: fluoroquinolones > penicillins > cephalosporins. The primary interactions of the degrading agent with fluoroquinolones occurred at the cyclic amine (i.e., piperazyl ring) and the benzene ring. Meanwhile, the cephalosporins and penicillins were initially attacked on the ß-lactam and sulfide groups. However, the tested penicillins presented an additional reaction on the central amide. In all cases, the transformations of antibiotics led to the antimicrobial activity decreasing. On the contrary, the toxicity level showed diverse results: increasing, decreasing, and no change, depending on the antibiotic type. In fact, due to the conservation of quinolone nucleus in the fluoroquinolone by-products, the toxicity of the treated solutions remained unchanged. With penicillins, the production of chloro-phenyl-isoxazole fragments increased the toxicity level of the resultant solution. However, the opening of ß-lactam ring of cephalosporin antibiotics decreased the toxicity level of the treated solutions. Finally, the application of the treatment to synthetic hospital wastewater and seawater containing a representative antibiotic showed that the high amount of chloride ions in seawater accelerates the pollutant degradation. In contrast, the urea and ammonium presence in the hospital wastewater retarded the removal of this pharmaceutical.