Determination of Prometryn in Vetiver Grass and Water Using Gas Chromatography-Nitrogen Chemiluminescence Detection

Perovskite Nanocrystals: Superior Luminogens for Food Quality Detection Analysis

With the global limited food resources receiving grievous damage from frequent climate changes and ascending global food demand resulting from increasing population growth, perovskite nanocrystals with distinctive photoelectric properties have emerged as attractive and prospective luminogens for the exploitation of rapid, easy operation, low cost, highly accurate, excellently sensitive, and good selective biosensors to detect foodborne hazards in food practices. Perovskite nanocrystals have demonstrated supreme advantages in luminescent biosensing for food products due to their high photoluminescence (PL) quantum yield, narrow full width at half-maximum PL, tunable PL in the entire visible spectrum, easy preparation, and various modification strategies compared with conventional semiconductors. Herein, we have carried out a comprehensive discussion concerning perovskite nanocrystals as luminogens in the application of high-performance biosensing of foodborne hazards for food products, including a brief introduction of perovskite nanocrystals, perovskite nanocrystal-based biosensors, and their application in different categories of food products. Finally, the challenges and opportunities faced by perovskite nanocrystals as superior luminogens were proposed to promote their practicality in the future food supply.

Development and validation of a GC × GC-ToFMS method for the quantification of pesticides in environmental waters

Water is a fundamental resource for living things, which is why its control is necessary. The widespread use of pesticides for agricultural and non-agricultural purposes has resulted in the presence of their residues in surface water and groundwater resources. Their presence in water is regulated through different directives, such as the Groundwater Directive, the Drinking Water Directive, and the Water Framework Directive, modified later several times, setting a maximum concentration of 0.1 µg.L^-1 for individual pesticides and their degradation products, and 0.5 µg.L^-1 for total pesticide residues present in a sample. There are different kinds of pesticides (e.g., organophosphorus and organochlorine pesticides, triazines, chloroacetamides, triazoles, (thio)carbamates) that have diverse chemical structures. Their determination and monitoring in a single analytical procedure are possible through multiresidue methods. In this study, 53 pesticides belonging to different chemical classes and their metabolites were selected based on their local occurrence and investigated in surface water and groundwater from agricultural areas susceptible to pesticide contamination. The methodology consisted of a classical solid-phase extraction (SPE) for the purification and enrichment of the pesticides, with a subsequent analysis in multidimensional gas chromatography coupled to mass spectrometry (GC×GC-MS). The quantification method was validated according to the Eurachem Guide in terms of linearity, precision, accuracy, limit of detection, and limit of quantification. After validation, the method was applied to 34 real-world water samples, and the results were compared with those obtained by a GC-QMS routine method.

Obtaining a Monoclonal Antibody against a Novel Prometryn-Like Hapten and Characterization of Its Selectivity for Triazine Herbicides

In this study, a previously unreported 3-((4-(isopropylamino)-6-(methylthio)-1,3,5-triazin-2-yl) amino) butyric acid hapten was designed and synthesized. This maximized the exposure of the antigen-determinant isopropyl of prometryn to the immune system in animals to induce the production of anticipated highly specific anti-prometryn antibodies. The hapten has a molecular weight of 285.37 Da. The compound was confirmed by nuclear magnetic resonance hydrogen spectroscopy (¹H NMR), nuclear magnetic resonance carbon spectroscopy (¹³C NMR), and high-resolution mass spectrometry (HRMS). By using the active ester approach, immunogens and coated antigens were created. Bovine serum albumin (BSA) was used as an immunogen, along with the successfully produced hapten, to immunize mice. The IC₅₀ value of mouse monoclonal anti-prometryn antibody (mAb) 7D4 (the quantity of analyte that generated 50% prometryn inhibition) was 3.9 ng/mL. The anti-prometryn mAb was of the IgG1 subclass. The IC₂₀ (80% binding level (B/B₀) of prometryn)-IC₈₀ (20% binding level (B/B₀) of prometryn) range of the anti-prometryn monoclonal antibody standard curve working range was 0.9-18.1 ng/mL. The prepared mAb has good characteristics because it can specifically recognize prometryn, and the cross-reaction rates for ametryn, desmetryn, and terbumeton were 34.77%, 18.09%, and 7.64%, respectively. The cross-reaction rate with the other seven triazines was less than 1%. The hapten structure proposed can serve as an additional tool for modulating selectivity in detecting triazines.

Ozone Degradation of Prometryn in Ruditapes philippinarum: Response Surface Methodology Optimization and Toxicity Assessment

ABSTRACT

This study optimized the method for ozone (O3) degradation of prometryn in the clam Ruditapes philippinarum and evaluated toxicity changes during ozone degradation. The gas chromatography method for the detection of prometryn was appropriately improved. The linear range was 5 to 500 ng/mL, with a correlation coefficient of 0.9964. The addition concentration of prometryn was 0.025 to 0.100 mg/kg, the recovery was 77.97 to 85.00%, the relative standard deviation (n = 6) was 2.36 to 7.86%, and the limit of detection was 0.3 μg/kg. Using the central composite design in two experiments, ozone as gas and ozone dissolved in water, the effect of degradation rate was studied on three variables: ozone concentration, temperature, and exposure time. Ozone as gas and ozone dissolved in water have the same degradation effect on prometryn. The O3 concentration was 4.2 mg/L, the temperature was 40°C, the exposure time was 10 min, and the maximum degradation rate was 89.94 and 89.69% for the two experiments, respectively. In addition, the toxicity of ozone degradation products was evaluated using buffalo rat liver cells. After ozone treatment for 30 min, the toxicity of the ozone degradation products was reduced to 52.15% compared with that of prometryn itself. The toxicity of the ozone degradation products increased slightly when the ozonation time was prolonged; the toxicity at 180 min was greater than that of the parent compound prometryn. Overall, the application of ozone degradation of pesticide residues is a promising new technology. This study determined better degradation conditions for prometryn in R. philippinarum and also provided a theoretical basis for the widespread use of ozone technology in the future.

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