Recent advances in catalyst design, performance, and challenges of metal-heteroatom-co-doped biochar as peroxymonosulfate activator for environmental remediation.

The escalation of global water pollution due to emerging pollutants has gained significant attention. To address this issue, catalytic peroxymonosulfate (PMS) activation technology has emerged as a promising treatment approach for effectively decontaminating a wide range of pollutants. Recently, modified biochar has become an increasingly attractive as PMS activator. Metal-heteroatom-co-doped biochar (MH-BC) has emerged as a promising catalyst that can provide enhanced performance over heteroatom-doped and metal-doped biochar due to the synergism between metal and heteroatom in promoting PMS activation. Therefore, this review aims to discuss the fabrication pathways (i.e., internal vs external doping and pre-vs post-modification) and key parameters (i.e., source of precursors, synthesis methods, and synthesis conditions) affecting the performance of MH-BC as PMS activator. Subsequently, an overview of all the possible PMS activation pathways by MH-BC is provided. Subsequently, Also, the detection, identification, and quantification of several reactive species (such as, •OH, SO4•-, O2•-, 1O2, and high valent oxo species) generated in the catalytic PMS system by MH-BC are also evaluated. Lastly, the underlying challenges associated with poor stability, the lack of understanding regarding the interaction between metal and heteroatom during PMS activation and quantification of radicals in multi-ROS system are also deliberated.

Exploring stingless bee honey from selected regions of Peninsular Malaysia through gas chromatography-mass spectrometry-based untargeted metabolomics.

Volatile organic compounds in honey are known for their considerable impact on the organoleptic properties of honey, such as aroma, flavor, taste, and texture. The type and composition of volatile organic compounds are influenced by entomological, geographical, and botanical origins; thus, these compounds have the potential to be chemical markers. Sixty-two volatile compounds were identified using gas chromatography-mass spectrometry from 30 Heterotrigona itama (H. itama) honey samples from 3 different geographical origins. Hydrocarbons and benzene derivatives were the dominant classes of volatile organic compounds in the samples. Both clustering and discriminant analyses demonstrated a clear separation between samples from distant origins (Kedah and Perak), and the volcano plot supported it. The reliability and predictability of the partial least squares-discriminant analysis model from the discriminant analysis were validated using cross-validation (R2 : 0.93; Q2 : 0.83; accuracy: 0.97) and the permutation test (p < 0.001), and the output depicted that the model is legitimate. In combination with the variable importance of projection (VIP > 1.0) and the Kruskal-Wallis test (p < 0.01), 19 volatile organic compounds (encompassed aldehydes, benzene derivatives, esters, hydrocarbons, and terpenoids) were sorted and named potent chemical markers in classifying honey samples from three geographical origins. In brief, this study illustrated that volatile organic compounds of stingless honey originated from the same bee species, but different geographical origins could be applied as chemical markers.

Impact of prolonged storage on quality assessment properties and constituents of honey: A systematic review.

This systematic review paper aims to discuss the trend in quality assessment properties and constituents of honey at different storage conditions and confer the possible whys and wherefores associated with the significant changes. Initially, a literature search was conducted through Google Scholar, ScienceDirect, PubMed, and Scopus databases. In total, 43 manuscripts published between 2001 and 2023 that met the inclusion and exclusion criteria were chosen for the review. As an outcome of this review, prolonged honey storage could deteriorate sensory, nutritional, and antioxidant properties and promote fermentation, granulation, microbial growth, carcinogenicity, organotoxicity, and nephrotoxicity. This systematic review also recognized that diastase activity, invertase activity, 5-hydroxymethylfurfural content, proline content, sugar content, amino acids, and vitamins could be used as indicators to distinguish fresh and stored honey based on the significant test (p-value) in the reported studies. However, all the reported studies used the simplest approach (one-way ANOVA) to identify the significant differences in the analyzed parameter during the storage period and none of them reported an approach to identify the most influential parameter at different storage conditions. In conclusion, orthogonal partial least squares discriminant analysis (supervised multivariate statistical tool) has to be employed in future studies to find the most influential parameter and could be used to potent chemical markers to distinguish fresh and stored honey because this analysis is incorporated with S-plot, variable importance of projection, and one-way ANOVA, which can produce the most accurate and precise results rather solely depending on one-way ANOVA.

Quality assessment and chemometrics application on physicochemical characteristics, antioxidant properties, and 5-HMF content of Malaysian stingless bee honey from different topographical origins.

The popularity of Malaysian stingless bee honey is rising among health-conscious individuals; thus, chemical and physical evaluations of Malaysian stingless bee honey are vital to ensure the honey has achieved the optimum limits set by Malaysian and international regulatory standards so that it can be commercialized locally and internationally. Therefore, in the present study, the physicochemical characteristics (moisture content, total dissolved solids, pH, free acidity, electrical conductivity, and ash content), antioxidant properties (total phenolic and flavonoid contents), and 5-hydroxymethylfurfural (5-HMF) of Heterotrigona itama (H. itama) honey from different sites in Peninsular Malaysia were investigated. Subsequently, the correlation between these chemical and physical parameters was studied using Spearman correlation coefficients. The significant difference between H. itama honey from different topographical origins was studied using univariate analysis (one-way ANOVA followed by post hoc Tukey's test). The discrimination pattern of 45 honey samples based on their topographical origins was evaluated using cluster analysis (heatmap and dendrogram) and chemometrics analysis (partial least squares-discriminant analysis). Results showed that some samples of certain parameters (electrical conductivity, free acidity, and moisture content) have exceeded the limit set by the international regulatory standard. However, the 5-HMF content of all samples was within the allowed range. A statistically significant difference (p < 0.05) has been observed for all the parameters except electrical conductivity and ash content in terms of inter-topographical origins. Although the profiles of H. itama honey from different origins were close, most of them were separated according to their topographical origins and were validated using a permutation test.

Fabrication and response optimization of Moringa oleifera-functionalized nanosorbents for the removal of diesel range organics from contaminated water.

The purpose of this research is to synthesize environmentally friendly nanosorbents for the novel adsorption of diesel range organics (DRO) from contaminated water. Central composite design (CCD) analysis of response surface methodology (RSM) was employed in a model fitting of the variables predicting the adsorption efficiency of Moringa oleifera-functionalized zerovalent iron particles (ZINPs) for the removal of DRO. The effects of the reaction parameters on the response were screened using 24 factorial designs to determine the statistically significant independent variables. A quadratic model predicting the DRO adsorption efficiency of ZINPs with an F value of 276.84 (p value < 0.0001) was developed. Diagnostic plots show that the predicted values were in excellent agreement with actual experimental values (R2 = 0.99). The maximum percentage removal of DRO of 92.6% was achieved after optimization, using the synthesized ZINPs after 8 h of contact between DRO substrates and ZINPs at pH of 8, the temperature of 25 °C, with an adsorbent dosage of 2 g/L and at composite desirability of 1. Characterization of ZINPs revealed the formation of quasi nanospheres and nanocubes with an average particle diameter of 50.9 ± 9.7, a crystallite size of 15.31 nm, a crystallinity index of 32.47% and a pore width of 75.69-88.59 nm. The adsorption equilibrium data modelling of ZINPs for adsorption of DRO was best described by Langmuir isotherm with the maximum monolayer coverage capacity of 7.194 mg/g. The separation factor [Formula: see text], indicated favourable adsorption. The adsorption kinetic data were consistent with pseudo-second-order kinetics indicating probable chemisorption.

Fast and Sensitive HPLC-ESI-MS/MS Method for Etoricoxib Quantification in Human Plasma and Application to Bioequivalence Study.

Etoricoxib is a non-steroidal anti-inflammatory drug (NSAID) used to treat pain and inflammation. The objective of the current study was to develop a sensitive, fast and high-throughput HPLC-ESI-MS/MS method to measure etoricoxib levels in human plasma using a one-step methanol protein precipitation technique. A tandem mass spectrometer equipped with an electrospray ionization (ESI) source operated in a positive mode and multiple reaction monitoring (MRM) were used for data collection. The quantitative MRM transition ions were m/z 359.15 > 279.10 and m/z 363.10 > 282.10 for etoricoxib and IS. The linear range was from 10.00 to 4000.39 ng/mL and the validation parameters were within the acceptance limits of the European Medicine Agency (EMA) and Food and Drug Analysis (FDA) guidelines. The present method was sensitive (10.00 ng/mL with S/N > 40), simple, selective (K prime > 2), and fast (short run time of 2 min), with negligible matrix effect and consistent recovery, suitable for high throughput analysis. The method was used to quantitate etoricoxib plasma concentrations in a bioequivalence study of two 120 mg etoricoxib formulations. Incurred sample reanalysis results further supported that the method was robust and reproducible.

Chemicals Constituents Isolated from Cultivate Alpinia conchigera Griff. and Antimicrobial Activity.

Alpinia conchigera Griff. is a plant species from the family Zingiberaceae. Coloquially known as wild ginger, Alpinia conchigera Griff. is used as food condiment and for traditional treatment of skin diseases. Isolation studies to identify bioactive compounds of rhizomes of Alpinia conchigera yielded seven compounds; 1'S-1'-acetoxychavicol acetate (1), trans-p-coumaryl diacetate (2), p-hydroxycinnamyl acetate (3), 1'S-1'-hydroxychavicol acetate (4) p-hydroxybenzaldehyde (5), stigmasterol (6) and ß-sitosterol (7). Compounds 1, 2 and 5 were evaluated for antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). Among the compounds tested, Compound 1 showed good antimicrobial activity against the strain of MRSA with minimum inhibition concentration (MIC) value of 0.5 mg/mL. Meanwhile, Compounds 2 and 5 exhibited moderate activity with MIC value between 1.0 and 2.0 mg/mL. These findings indicate antimicrobial potential of 1'S-1'-acetoxychavicol acetate (1), compound derived from rhizome of Alpinia conchigera Griff. against MRSA, which warrant further investigation.

Magnetic nanoparticles assisted dispersive liquid-liquid microextraction of chloramphenicol in water samples.

This work describes the development of a new methodology based on magnetic nanoparticles assisted dispersive liquid-liquid microextraction (DLLME-MNPs) for preconcentration and extraction of chloramphenicol (CAP) antibiotic residues in water. The approach is based on the use of decanoic acid as the extraction solvent followed by the application of MNPs to magnetically retrieve the extraction solvent containing the extracted CAP. The coated MNPs were then desorbed with methanol, and the clean extract was analysed using ultraviolet-visible spectrophotometry. Several important parameters, such as the amount of decanoic acid, extraction time, stirring rate, amount of MNPs, type of desorption solvent, salt addition and sample pH, were evaluated and optimized. Optimum parameters were as follows: amount of decanoic acid: 200 mg; extraction time: 10 min; stirring rate: 800 rpm; amount of MNPs: 60 mg; desorption solvent: methanol; salt: 10%; and sample pH, 8. Under the optimum conditions, the method demonstrated acceptable linearity (R 2 = 0.9933) over a concentration range of 50-1000 µg l-1. Limit of detection and limit of quantification were 16.5 and 50.0 µg l-1, respectively. Good analyte recovery (91-92.7%) and acceptable precision with good relative standard deviations (0.45-6.29%, n = 3) were obtained. The method was successfully applied to tap water and lake water samples. The proposed method is rapid, simple, reliable and environmentally friendly for the detection of CAP.

Extraction of biogenic amines using sorbent materials containing immobilized crown ethers.

Three sorbent materials (A18C6-MS, DA18C6-MS and AB18C6-MS) based on the crown ether ligands, 1-aza-18-crown-6, 1,4,10,13-tetraoxa-7,16-diazacyclo octadecane and 4'-aminobenzo-18-crown-6, respectively, were prepared by the chemical immobilization of the ligand onto mesoporous silica support. The sorbents were characterized by FT-IR, scanning electron microscopy-energy dispersive X-ray microanalysis, elemental analysis and nitrogen adsorption-desorption test. The applicability of the sorbents for the extraction of biogenic amines by the batch sorption method was extensively studied and evaluated as a function of pH, biogenic amines concentration, contact time and reusability. Under the optimized conditions, all the sorbents exhibited highest selectivity toward spermidine (SPD) compared to other biogenic amines (tryptamine, putrescine, histamine and tyramine). Among the sorbents, AB18C6-MS offer the highest capacity and best selectivity towards SPD in the presence of other biogenic amines. The AB18C6-MS sorbent can be repeatedly used three times as there was no significant degradation in the extraction of the biogenic amines (%E>85). The optimized procedure was successfully applied for the separation of SPD in food samples prior to the reversed-phase high performance liquid chromatography separation.

In situ derivatization hollow fibre liquid-phase microextraction for the determination of biogenic amines in food samples.

Hollow fibre liquid-phase microextraction with in situ derivatization using dansyl chloride has been successfully developed for the high-performance liquid chromatography-ultraviolet (HPLC-UV) determination of the biogenic amines (tryptamine, putrescine, cadaverine, histamine, tyramine, spermidine) in food samples. Parameters affecting the performance of the in situ derivatization process such as type of extraction solvent, temperature, extraction time, stirring speed and salt addition were studied and optimized. Under the optimized conditions (extraction solvent, dihexyl ether; acceptor phase, 0.1M HCl; extraction time, 30 min; extraction temperature, 26 degrees C; without addition of salt), enrichment factors varying from 47 to 456 were achieved. Good linearity of the analytes was obtained over a concentration range of 0.1-5 microg mL(-1) (with correlation coefficients of 0.9901-0.9974). The limits of detection and quantification based on a signal-to-noise ratio of 3-10, ranged from 0.0075 to 0.030 microg mL(-1) and 0.03 to 0.10 microg mL(-1), respectively. The relative standard deviations based on the peak areas for six replicate analysis of water spiked with 0.5 microg mL(-1) of each biogenic amine were lower than 7.5%. The method was successfully applied to shrimp sauce and tomato ketchup samples, offering an interesting alternative to liquid-liquid extraction and solid phase extraction for the analysis of biogenic amines in food samples.