A non-derivatized high-performance liquid chromatographic (HPLC) method was developed for the simultaneous quantification of hydroxyl acids and their amination products in ammonolysis reaction mixtures. By optimizing the mobile phase composition and pH (0.04 M KHPO-5% methanol, pH = 2.7), complete separation of hydroxyl acids and their amination products was achieved, using lactic acid as a model substrate. Lactic acid exhibited excellent linearity within the range of 0.02 to 25 mM ( = 0.99968), with a relative standard deviation (RSD, = 6) of 3.51% and a recovery ratio between 96.10% and 102.23%. Similarly, alanine exhibited good linearity from 0.02 to 50 mM ( = 0.99999) with an RSD of 4.04% and recovery ratios between 97.30% and 100.03%. Both analytes demonstrated good intra-day precision, with RSDs of 4.23% and 1.18%, respectively. The substrate universality tests confirmed the method's ability to rapidly and effectively separate other hydroxyl acids and their corresponding amino acids in ammonolysis reactions. The results of quantitative comparison with AQC, PITC, and OPA derivatization also proved the method to be a reliable approach for the individual or simultaneous quantification of hydroxyl acids and amino acids, offering essential support for monitoring the conversion ratio and selectivity in hydroxyl acid amination processes. Moreover, it provides valuable guidance for optimizing the amination reaction of hydroxyl groups, potentially extending catalytic advantages to other related reactions.

In this study, magnesium-doped lithium manganese oxide nanoparticles were prepared through a solid-state reaction technique, and their surface was modified with mesoporous silica. The surface-modified material exhibited a significantly enhanced BET surface area from 5.791 to 66.058 m g, thus enhancing the adsorption property. The prepared material was characterized using advanced analytical techniques such as powder XRD (PXRD), FT-IR, BET surface area analysis, and scanning electron microscopy (SEM). The effect of the adsorbent dosage, contact time, pH, and initial concentration on adsorption characteristics was evaluated for methylene blue (MB) dye. A maximum adsorption capacity of 94.34 mg g was obtained from the Langmuir adsorption isotherm. Kinetic properties were characterized using the pseudo-first-order, pseudo-second-order, and intra-particle diffusion models, and the pseudo-second-order model was found to be the best fit. Effectively, four cycles of adsorption-desorption for the prepared material were demonstrated through thermal desorption technique. To understand the feasibility of adsorption in different matrix conditions, MB dye-spiked samples of well water, lake water, and tap water were treated with the adsorbent material and 64.5%, 62.8%, and 53.5% removal performance, respectively, was observed. In addition, mixed solutions of heavy metals (Co, Ni, Cu, Zn, and Pb) were also tested for adsorption performance study of the adsorbent and 65.5-99.7% removal was observed at a sample dose of 25 g L.

Correction for 'A comparative review on the mitigation of metronidazole residues in aqueous media using various physico-chemical technologies' by Moosa Es'haghi , , 2024, , 7294-7310, https://doi.org/10.1039/D4AY01502A.

Adenosine triphosphate (ATP) is crucial for cellular activity. The need for ATP detection in the field of biomedicine is rapidly increasing. Several biosensor-based approaches have been developed as a result of the growing demand for ATP detection. An electrolyte-insulator-semiconductor (EIS) sensor is a type of field-effect device that has the ability to detect surface-potential changes with a specific level of sensitivity. In this study, a label-free ATP detection biosensor based on poly(amidoamine)-modified EIS sensors was developed, in which an ATP-sensitive aptamer (Apt) was utilized as the sensitive element and the EIS sensor was used as the transducer. It is possible to monitor the binding of charged molecules, such as aptamers using EIS sensors in a label-free manner with a straightforward setup. To improve the coupling efficiency of Apt with the EIS sensor, a positively charged polyelectrolyte, , poly (amidoamine) (PAMAM) dendrimers, was utilized to modify the surface of the EIS sensors to attach the negatively charged Apt through electrostatic attraction. The adsorptive binding of Apt and ATP results in a change in the capacitance of the EIS sensor. During the process of surface modification, the electrochemical measurements of capacitance-voltage (-) curves and constant-capacitance (ConCap) characteristics were utilized as indicators for the corresponding processes of EIS sensor surface modification. The measurement results indicated that this biosensor was able to detect ATP with high sensitivity and good specificity. The detection range of ATP was from 0.1 nM to 100 nM and the detection limit was as low as 0.12 nM. This biosensor has the potential to be utilized in the detection of ATP in the surrounding microenvironment of cells and tissues, with promising prospects for application in the field of biomedicine such as energy and metabolism monitoring of cells and tissues.

this study aimed to examine the effect of different storage times (0, 7, 24, 57, and 119 days) on the volatile components of Shenling Baizhu powder across different preparation processes (Pharmacopoeia, ultra-micro pulverization-pulverization, and microparticle design methods). The findings offer insights to guide quality control measures for Shenling Baizhu powder.

Nitrogen blowdown evaporation (NBE) is a widely used technique for solvent removal. It is explicitly called for in the procedures for a wide range of analytical methods developed by regulatory and scientific agencies, and stands as a valuable tool in the sample preparation toolbox. However, commercially available equipment to perform NBE can be quite expensive, especially while working through different approaches to sample handling in the early stages of a research or analysis project. This paper details the design and construction of a homebuilt nitrogen blowdown evaporator with conventional and low-cost materials and processes, coming in at ∼20% the cost of commercial equipment. A proof-of-function experiment was carried out using the apparatus to evaporate a solution containing three per- and polyfluoroalkyl substances (PFAS). This study showed that: (1) the careful selection of materials in the design of the apparatus avoided detectable background contamination; (2) the apparatus functioned with little to no analyte loss (recoveries of 99-100% after blowdown and solvent reconstitution); and (3) evaporation times compared favorably with other designs and applications of NBE hardware. Adaptations of the apparatus for different sample containers are discussed. The ESI† includes plans and detailed instructions for the assembly and operation of the apparatus.

Dioxins rank among the most hazardous persistent organic pollutants, presenting a serious threat due to their long environmental lifespan and capacity for bioaccumulation. This comprehensive review delves into the historical, chemical, and toxicological aspects of dioxins, spotlighting significant incidents such as the Seveso disaster and the repercussions of Agent Orange. The review offers a thorough analysis of the sources of dioxin formation, encompassing natural occurrences like volcanic eruptions and wildfires, alongside man-made activities such as industrial combustion and waste incineration. It examines regional variations in dioxin contamination, revealing air concentrations that can range from less than 0.01 pg TEQ per m in remote regions to as high as 2 pg TEQ per m in urban environments. With global dioxin emissions estimated at around 97.0 kg TEQ per year, Asia and Africa emerge as the highest emitters among the continents, with the total global dioxin release approximately at 100.4 kg TEQ annually. Dioxin emissions per capita show stark contrasts across six continents, from 10.77 g TEQ per capita in Europe to a concerning 71.66 g TEQ per capita in Oceania. Furthermore, the concentration of dioxin compounds produced during combustion varies significantly, ranging from 15 to 555 ng m. While dioxin emission regulations are intricate and differ globally, most nations require that concentrations remain below one ng m. Globally, dioxin production is estimated at 17 226 kilograms annually, equating to about 287 kilograms in toxic equivalent (TEQ). This review critically examines the severe health implications of dioxins, which include carcinogenic effects, endocrine disruption, and immunotoxicity. Innovative remediation strategies, such as using nanomaterials for adsorption and advanced oxidation processes, are identified as promising pathways to tackle this pressing issue. Ultimately, this review underscores the necessity for enhanced monitoring systems and comprehensive policy frameworks to facilitate sustainable dioxin management and regulatory compliance. Taking decisive action is vital to protect public health and the environment from the ongoing threat posed by dioxins.

The serious contamination of ochratoxin A (OTA) in agricultural products has promoted the development of rapid, sensitive, and selective analytical methods for OTA monitoring. We demonstrated a competitive aptasensor for OTA detection using CRISPR/Cas12a as an effective signal amplifier. OTA competes with complementary DNA of the aptamer on the microplate to bind to the aptamer. Streptavidin bridges the biotinylated aptamer and biotinylated activator to convert the OTA input into Cas12a activation, which cleaves fluorescent DNA reporters. Under optimized experimental conditions, the aptasensor was demonstrated to work well for sensitive detection of OTA, with a linear range from 0.5 nM to 62.5 nM and a detection limit of 0.5 nM. Moreover, our method not only exhibits high selectivity, but also has satisfactory anti-interference ability against complex sample matrices. Taken together, the CRISPR/Cas12a-based competitive aptasensor offers a simple and sensitive platform for OTA detection, and it holds great promise for food security monitoring.

The field of electrochemical ammonia synthesis has made rapid advancements, attracting a large number of scientists to contribute to this area of research. Accurate detection of ammonia is crucial in this process for evaluating the efficiency and selectivity of electrocatalysts. In this study, we systematically investigate the indophenol blue method for ammonia detection, examining the effects of key factors such as solution pH, nitrate concentration, and metal ion concentration on measurement accuracy. Based on experimental optimization and mathematical algorithms, we propose an iterative refinement method supported by custom-developed code. This method automates the generation and adjustment of calibration curves, reduces measurement errors, and enhances detection precision, offering a valuable framework for the quantitative detection of ammonia and other small molecules in electrochemical synthesis.

Rapid and accurate methods for tracing and identifying the origin of lamb are crucial for ensuring food authenticity and quality. This study developed a precise traceability method to determine the origin of lamb by integrating rapid evaporative ionization mass spectrometry (REIMS) with multivariate statistical analysis. Lamb samples from Xilin Gol, Ordos, and Hulun Buir ranches were identified by REIMS fingerprinting within 1 min. The discrimination model based on lipid molecular features achieved the highest recognition accuracy of 99.14% compared to models based on small-molecule metabolites (91.59%), fatty acids (98.52%), and full-spectrum molecules (98.49%). Furthermore, differential analyses were conducted to assess lamb meat from different origins and feeding methods (grazing feedlot) using REIMS fingerprints. Lamb products from the Xilin Gol ranch exhibited significantly lower glycerophosphate (PA) content compared to lambs from other regions, while grazing resulted in significantly lower PA content in lamb meat compared to those fed in feedlots. Additionally, meat from grazed lambs had significantly higher unsaturated fatty acid content, providing molecular evidence for its superior nutritional quality and distinct flavor profile compared to the lambs from feedlot systems. REIMS is a promising tool for rapid discrimination of lamb meat from different origins and feeding systems with high accuracy, offering valuable technical support for lamb origin traceability and quality assessment.

Ammonia or biogenic amines released by protein degradation during food spoilage have various ill effects on human health and the environment. Herein, an economical colorimetric bisphenol-based sensor was developed from inexpensive reagents and a simple synthetic method for detecting ammonia and monitoring food spoilage. The slightest addition of NH significantly changed the absorption of BP, which was reflected in the detection limit value for NH (7.89 × 10 M). The film-based sensor developed by immobilizing BP onto a starch-polyvinyl alcohol (PVA) matrix enabled both the rapid and visual onsite detection of ammonia and the determination of the RGB contents using a digital application. The blue content of the film linearly changed with the extent of the spoilage of fish and meat samples. This linear change enabled the film-based sensor to act as an excellent food quality indicator for hourly food quality monitoring. The aerial reversibility of the film empowered its use for many cycles without the use of any reagents.

Sodium dodecyl sulfate (SDS) is widely used in numerous household products and pharmaceuticals due to its excellent water solubility, emulsification, foaming, and dispersing properties. However, the extensive use of SDS has made it a significant environmental pollutant, posing a great threat to aquatic ecosystems. Therefore, developing a rapid, efficient, and sensitive probe for detecting SDS in aqueous environments is crucial. In this study, we present a cationic imidazolium-conjugated perylene bisimide (PBI) compound, as an effective probe for detecting SDS in aqueous media. The probe exhibits a distinct color change from dark pink to light pink upon interaction with SDS, making it a simple yet powerful tool for naked-eye detection. Moreover, the strong electrostatic interaction between the positively charged PBI compound and the negatively charged sulfate group in SDS leads to the formation of closely packed molecular aggregates. This results in significant quenching of fluorescence emission, enabling the detection of SDS at micromolar concentrations. We further demonstrate the practical application of PBI compound for sensitive and selective fluorometric detection of SDS in home-care items and tap water samples. These findings highlight the potential of such compounds as versatile tools for both environmental monitoring and product safety applications involving sulfate-containing species.

Electrochemiluminescence (ECL) of luminol and electrocatalysis by Prussian blue were compared for the selective detection of HO at the boron-doped diamond (BDD) electrodes. The HO detection was optimized by various parameters such as the applied potential at pH 7.4, which is a physiological value usually used for HO detection in enzymatic reactions. At an optimum applied potential of +0.5 V, a linear increase in the ECL signals ( = 0.99) was achieved for HO concentrations ranging between 0 to 100 μM with an estimated limit of detection (LOD) of 2.59 μM. This LOD was better than that obtained with electrocatalysis measurements using the same electrode modified with Prussian blue. Furthermore, the interference study in the presence of glucose, Fe, Cl, Ca, CO, Na, and F ions showed a comparable selectivity of the luminol ECL and PB-BDD electrochemical current. Nevertheless, the ECL method exhibited significant advantage in the high stability of its signal response.

Triterpenoids are known for their promising biological activities, and there is a growing focus on green extraction methods for these compounds. In this study, ultrasound-assisted deep eutectic solvents were employed to extract triterpenoids from persimmon leaves, with choline chloride-lactic acid identified as an effective green solvent. The extraction conditions were carefully optimized using response surface methodology, resulting in an extraction efficiency of 12.41%, which is 1.54 times higher than that achieved with conventional organic solvents such as methanol. The triterpenoids were then successfully recovered using a solid-liquid extraction method based on AB-8 macroporous resins, achieving a 94.01% recovery rate with a final product triterpenoid content of 81.87%. These findings provide a strong foundation for the sustainable extraction of triterpenoids and other valuable compounds from biomass.

Wasabi is a type of sauce made from the plant horseradish. During its production and storage, gas production sometimes occurs, which leads to changes in the flavor quality of wasabi. In this study, an electronic nose, electronic tongue, headspace-gas chromatography-mass spectrometry and headspace-gas chromatography-ion mobility spectrometry combined with multivariate statistical analysis were used to compare the differences in odor, taste and volatile components between normal and gas-producing wasabi. The results showed that normal and gas-producing wasabi samples could be distinguished by the electronic nose and electronic tongue. Furthermore, 72 and 65 volatile components were identified from wasabi by headspace-gas chromatography-mass spectrometry and headspace-gas chromatography-ion mobility spectrometry analysis, respectively. In addition, 33 key volatile components that caused the difference between normal and gas-producing wasabi were identified through variable projection importance index analysis. Therefore, normal and gas-producing wasabi could be effectively distinguished and their differences in odor, taste and volatile components could be clarified by the four flavor analysis techniques combined with multivariate statistical analysis, which provide a scientific basis for the quality control and process optimization of wasabi.

Platelet factor 4 (PF4), a specific protein primarily found in megakaryocytes and platelet α-granules, plays an essential role in the coagulation process. It carries a high positive charge and thus has a unique ability to readily form complexes with negatively charged heparin. This interaction between PF4 and heparin plays a crucial role in platelet aggregation and thrombosis, resulting in heparin-induced thrombocytopenia (HIT). HIT is often diagnosed through various diagnostic tests that utilize exogenous PF4 detecting antibodies against PF4/heparin complexes. Besides, PF4 was recently found to have the potential to restore cognitive function. Therefore, a comprehensive characterization of biosynthetic PF4 standards is crucial for the diagnosis and management of HIT. In this study, a bacterial expression system was established to efficiently produce recombinant human PF4 (rhPF4). This PF4 was characterized using liquid chromatography-high resolution mass spectrometry, confirming it is completely identical to native PF4 in terms of disulfide connectivity and sequence. The chemotaxis assay indicates that it possesses biological activity. Furthermore, PF4 contains two disulfide bonds, which are crucial for its structural integrity and function. A partial reduction method was successfully developed to assign the disulfide bond connectivity as Cys10-Cys36 and Cys12-Cys52.

A method involving gas chromatography coupled with quadrupole/orbitrap high-resolution mass spectrometry (GC-Q/Orbitrap HRMS) with the QuEChERS method was developed to analyze 36 non-phthalate plasticizers in milk powder products. The samples were dissolved in 20% NaCl, extracted with acetonitrile, and purified using silica, PSA, and C. The results showed the excellent linear relationship of the calibration curves of 36 non-phthalate plasticizers in the range of 10-1000 ng mL, with correlation coefficients () not less than 0.995. The limit of detection (LODs) of 36 non-phthalate plasticizers ranged from 0.02 to 0.04 mg kg, and the limit of quantification (LOQs) ranged from 0.04 to 0.08 mg kg. The recovery rates were between 64.1% and 116.5%, with the relative standard deviation less than 10%. The proposed method was applied to the detection and analysis of 36 non-phthalate plasticizers in 50 milk powder samples. The findings indicate that this highly sensitive, accurate, and high-throughput method is suitable for the rapid screening and identification of 36 non-phthalate plasticizers in milk powder products.

This work deals with the development of a greener RP-HPLC method and chemical pattern recognition for the identification of L. collected from different natural sources and samples traded as '' in Indian herbal drug markets. The simultaneous quantification of α- and β-asarone was performed using 0.10% orthophosphoric acid (A) and acetonitrile (B) as solvents in an isocratic manner (35 : 65 v/v) at 0.70 mL min. The developed method was found to be greener using various metrics such as AES, GAPI, NEMI, AGREE, and AGREEprep than existing methods. The LC chromatogram obtained in this study showed 11 common peaks, with β-asarone (peak 10) and α-asarone (peak 11) as major markers, which were identified at an of 10.69 ± 0.08 and 10 ± 0.06 minutes, respectively, while their content varied from 0.02 ± 0.001 to 0.71 ± 0.07 and 2.76 ± 0.03 to 39.26 ± 0.14 μg mg, respectively. Chemical pattern recognition was applied for quality evaluation of samples, and hierarchical cluster analysis bifurcated 17 samples into two categories. Principal component analysis integrated with orthogonal partial least squares discriminant analysis showed that the first two principal components efficiently reflect the similarity and differences among populations. Further, the components P7, P10 (β-asarone) and P11 (α-asarone) will serve as 'landmark components' for quality evaluation of natural and marketed samples. Results show that traded samples share chemical similarity with authentic , while common adulterants (, , and ) have entirely different profiles. The integration of HPLC fingerprint and chemical pattern recognition will provide a scientific rationale for the identification of the authentic raw drug and quality control of its adulterants/substitutes.

Platelet-derived growth factor-BB (PDGF-BB), an important protein biomarker, is closely associated with tumorigenesis. Therefore, it is important to develop a simple and sensitive method to detect PDGF-BB. Herein, we developed a dual recycling signal amplification strategy for colorimetric and sensitive detection of PDGF-BB using a PDGF-BB specific aptamer. In the presence of PDGF-BB, the first entropy-driven circuit (EDC) reaction cycle was triggered for colorimetric signal amplification. Meanwhile, a catalytic Mg-dependent DNAzyme was formed on one side of the EDC product, which could cleave its substrate and generate numerous "mimic trigger" DNA products. Then, an autocatalytic EDC (AEDC) reaction was triggered by the "mimic trigger" DNA, and the signal amplification efficiency of this colorimetric assay was significantly improved. This AEDC- and DNAzyme-based colorimetric assay showed a good linear range from 5.0 to 100 nM for PDGF-BB and the limit of detection was calculated to be 2.2 nM. In addition, PDGF-BB has been quantitatively detected in human serum samples. This colorimetric assay can be easily extended to detect different protein biomarkers by using other recognition elements (aptamers) and shows great potential for clinical diagnosis and prognosis.

In this work, a peroxidase-like (POD-like) nanozyme of Fe/P-NC was synthesized by doping phosphorus (P) and nitrogen (N) to manipulate iron (Fe) activity centers, which showed catalytic activity and kinetics comparable to those of natural HRP. Based on the efficient POD-like activity of the Fe/P-NC nanozyme and cascaded catalytic reactions with acetylcholinesterase (AChE), we constructed a colorimetric, affordable and sensitive sensing platform to detect organophosphorus pesticides (OPs). In the presence of AChE, the POD-like activity of the prepared Fe/P-NC was suppressed, which weakened the Fe/P-NC-catalyzed oxidation of TMB. After the introduction of OPs, the catalytic activity of the Fe/P-NC nanozyme was restored, resulting in efficient oxidation of TMB and an increasing blue color. By monitoring the variation in UV-vis absorbance, OPs could be quantitatively analyzed. The proposed colorimetric method exhibited superior analytical performance, with a wide detection range of 0.5-100 ng mL and a low detection limit of 0.13 ng mL for OPs. The assay was successfully employed to detect methyl parathion in fruit and vegetable samples. This work provides new insights into the design of new efficient nanozymes for the rapid and low-cost detection of OPs in real samples.

Nitrosamine impurities, particularly nitrosamine drug substance-related impurities (NDSRIs), pose significant health risks due to their potential mutagenicity and carcinogenicity. Consequently, stringent regulatory guidelines have been established for their detection and quantification in pharmaceutical products. This study presents a simple, robust, and ultrasensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify the -nitroso-dabigatran etexilate (NDE) impurity in the drugs and capsules of dabigatran etexilate (DEM) using an electrospray ionization technique. Using a gradient elution program, with mobile phase A consisting of 5 mM ammonium formate buffer (pH 7.0 ± 0.1) and mobile phase B 100% acetonitrile, chromatographic separation was achieved on a Sapphirus C18 HP-classic column (250 mm × 4.6 mm × 5 μm). The system utilized an Agilent 1290 infinity series LC with a 6470B LC/TQ tandem mass spectrometer, operating at a 0.6 mL min column flow rate. Detection and quantitation of the -nitroso dabigatran etexilate (NDE) impurity were performed in positive ESI mode using multi-reaction monitoring (MRM). The validation of the method adhered to the ICH Q2 (R2) guidelines, showing excellent signal-to-noise ratios for the detection and quantification limits, with linearity observed (correlation coefficient > 0.99) over a range of 18-120 ppb. Accuracy was confirmed through recovery studies, yielding satisfactory results between 80 and 120% of spiked concentrations. This validated LC-MS/MS method is suitable for routine and stability analysis of -nitroso-dabigatran etexilate (NDE) impurities in both drug substance and finished capsules.