Dissipation of tiafenacil in five types of citrus orchard soils using the HPLC‐MS coupled with the quick, easy, cheap, effective, rugged, and safe method

Degradation of the novel herbicide tiafenacil in aqueous solution: Kinetics, various influencing factors, hydrolysis products identification, and toxicity assessment

As new pesticides are continually introduced into agricultural systems, understanding their environmental behavior and potential toxicity effects is crucial for effective risk assessment. This study utilized QuEChERS and UPLC-QTOF-MS/MS techniques to analyze Tiafenacil (TFA) and its six hydrolysis products (HP1 to HP6) in water, marking the first comprehensive report on these degradation products. Calibration curves demonstrated strong linearity (R2 ≥ 0.9903) across concentrations ranging from 0.02 to 3.50 mg L-1. TFA's hydrolysis followed single first-order kinetic (SFOK) model, with rapid degradation observed under alkaline and high-temperature conditions, resulting in half-lives ranging from 0.22 to 84.82 days. The ECOSAR model predicts that TFA's hydrolysis products exhibit acute and chronic toxicity to fish, Daphnia, and green algae. Additionally, hydrolysis products HP1, HP5, and HP6 were detected in irrigation water from citrus orchards, posing higher predicted toxicity risks to fish and green algae. This highlights the necessity for further risk assessments considering transformation products. Overall, this study enhances our understanding of TFA's environmental fate and supports its safe agricultural application and monitoring practices.

Development and Application of a New QuEChERS Method Coupled with UPLC-QTOF-MS/MS for Analysis of Tiafenacil and Its Photolysis Products in Water

This research centered on the novel pyrimidinedione herbicide, tiafenacil. Residues of tiafenacil and its three photolysis products (PP1 to PP3) in water were analyzed using advanced QuEChERS and UPLC-QTOF-MS/MS techniques, reaching a low limit of quantitation (LOQ) of 10 μg/L. Calibration curves exhibited a high degree of linearity (R2 ≥ 0.993) over a concentration range of 0.01 to 1.00 mg/L. Method validation demonstrated high precision, with intraday relative standard deviation RSDr ≤7.9% and interday RSDR ≤ 6.1%, along with high accuracy (recoveries from 94.4% to 105.0%). Using density functional theory (DFT) at the B3LYP/6-311g (d) level, we calculated the electronic properties of tiafenacil and its PPs (PP1 to PP3). Additionally, frontier molecular orbital (FMO) and fukui function analyses were conducted to explore HOMO-LUMO energies, determine energy band gaps for these substances, and predict reactive sites for their electrophilic, nucleophilic, and radical reactions. Significantly, ecotoxicity assessment, including ECOSAR predictions and acute toxicity tests, revealed that the PPs exhibited higher ecotoxicity to aquatic organisms than tiafenacil. Field experiments showed a half-life of 18.9 days for tiafenacil in water, fitting a first-order kinetic model (R2 = 0.999), with a degradation of 41.5% after 14 days and approximately 89.2% after 60 days. This study significantly advances our understanding of tiafenacil's environmental fate, evaluates its associated risks, and offers valuable insights for its responsible application.

Concurrent Analysis of Tiafenacil and Its Transformation Products in Soil by Using Newly Developed UHPLC-QTOF-MS/MS-Based Approaches

As new pesticides continue to emerge in agricultural systems, understanding their environmental behavior is crucial for effective risk assessment. Tiafenacil (TFA), a promising novel pyrimidinedione herbicide, was the focus of this study. We developed an efficient QuEChERS-UHPLC-QTOF-MS/MS method to measure TFA and its transformation products (TP1, TP2, TP3, TP4, and TP5) in soil. Our calibration curves exhibited strong linearity (R2 ≥ 0.9949) ranging from 0.015 to 2.0 mg/kg within a low limit of quantification (LOQ) of 2.0 µg/kg. Inter-day and intra-day recoveries (0.10 to 2.0 mg/kg, 80.59% to 110.05%, RSD from 0.28% to 12.93%) demonstrated high sensitivity and accuracy. Additionally, TFA dissipation under aerobic conditions followed first-order kinetics, mainly yielding TP1 and TP4. In contrast, TP1 and TP2 were mainly found under sterilized and anaerobic conditions, and TFA dissipation followed second-order kinetics. Moreover, we predicted the transformation pathways of TFA using density functional theory (DFT) and assessed the toxicity levels of TFA and its TPs to aquatic organisms using ECOSAR. Collectively, these findings hold significant implications for a better understanding of TFA fate in diversified soil, benefiting its risk assessment and rational utilization.

Evaluation of Iron Chlorin e6 disappearance and hydrolysis in soil and garlic using salting-out assisted liquid-liquid extraction coupled with high-performance liquid chromatography and ultraviolet-visible detection

Iron Chlorin e6 (ICE6), a star plant growth regulator (PGR) with independent intellectual property rights in China, has demonstrated its efficacy through numerous field experiments. We innovatively employed salting-out assisted liquid-liquid extraction (SALLE) with HPLC-UV/Vis to detect ICE6 residues in water, soil, garlic seeds, and sprouts. Using methanol and a C18 column with acetonitrile: 0.1% phosphoric acid mobile phase (55:45, v:v), we achieved a low LOQ of 0.43 to 0.77 μg kg-1. Calibration curves showed strong linearity (R2 > 0.992) within 0.01 to 5.00 mg kg-1. Inter-day and intra-day recoveries (0.05 to 0.50 mg kg-1) demonstrated high sensitivity and accuracy (recoveries: 75.36% to 107.86%; RSD: 1.03% to 8.78%). Additionally, density functional theory (DFT) analysis aligned UV/Vis spectra and indicated ICE6's first-order degradation (2.03 to 4.94 days) under various environmental conditions, mainly driven by abiotic degradation. This study enhances understanding of ICE6's environmental behavior, aids in risk assessment, and guides responsible use in agroecosystems.

Low-background interference detection of glyphosate, glufosinate, and AMPA in foods using UPLC-MS/MS without derivatization

The abuse of herbicides has emerged as a great threat to food security. Herein, a low-background interference detection method based on UPLC-MS was developed for the simultaneous determination of glufosinate, glyphosate, and its metabolite aminomethylphosphonic acid (AMPA) in foods. Initially, this study proposed a simple and rapid pretreatment method, utilizing water extraction and PRiME HLB purification to isolate glyphosate, glufosinate, and AMPA from food samples. After the optimization of pretreatment conditions, the processed samples are then analyzed directly by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) without pre-column derivatization. The method can effectively reduce interference from by-products of pre-column derivatization and background substrates of food sample, showing low matrix effects (ME) ranging from - 24.83 to 32.10%. Subsequently, the method has been validated by 13 kinds of food samples. The recoveries of the three herbicides in the food samples range from 84.2 to 115.6%. The limit of detection (LOD) is lower to 0.073 mg/kg, 0.017 mg/kg, and 0.037 mg/kg, respectively. Moreover, the method shows an excellent reproducibility with relative standard deviations (RSD) within 16.9%. Thus, the method can provide high trueness, reproducibility, sensitivity, and interference-free detection to ensure human health safety.

Protective effect of Peucedanum praeruptorum Dunn extract on oxidative damage of LLC‑PK1 cells induced by H2O2

Peucedanum praeruptorum Dunn extract (PPDE) is a well-known treatment used in traditional Chinese medicines, where it is most commonly used to treat coughs and symptoms such as headaches and fever. In the present study, the antioxidant capacity of PPDE in vitro was determined by scavenging experiments using DPPH, ABTS+·, ·OH, and ·O2-. The cell survival rate was determined by MTT assay. The MDA, SOD, CAT, GSH, and GSH-Px content were determined by colorimetry assays. The expression levels of antioxidant genes SOD, CAT, GSH, and GSH-Px were assessed by reverse transcription-quantitative PCR. HPLC was used to identify the PPDE components. The results suggested that PPDE had scavenging effects on DPPH, ABTS, hydroxyl, and superoxide anion radicals in a concentration-dependent manner; H2O2 treatment resulted in oxidative stress in LLC-PK1 cells, and the degree of injury of LLC-PK1 cells following PPDE treatment was improved, which was positively correlated with its concentration. Peucedanum praeruptorum Dunn extract treatment reduced the content of MDA and increased the content of CAT, SOD1, GSH, and GSH-Px. The mRNA expression levels of antioxidant genes detected by quantitative PCR were consistent with changes in CAT, SOD, GSS, and GSH-Px. Additionally, the trend in CAT, SOD1, GSH, and GSS protein expression levels was also consistent at the mRNA level. PPDE was found to consist of isochlorogenic acid C, myricetin, baicalin, luteolin, and kaempferol. Therefore, PPDE, which was formed of products derived from natural substances, functioned in the inhibition of oxidative damage. The present study aimed to obtain a better understanding of the traditional Chinese medicine Peucedanum praeruptorum Dunn and preliminarily elucidate its antioxidant mechanism at the cellular level. Further animal or human experiments are required to verify the antioxidant effects of PPDE for further development and utilization.

Dissipation kinetics of chlorpyrifos and 3,5,6 trichloro-2-pyridinol under vegetation of different aromatic grasses: Linkage with enzyme kinetics and microbial community of soil

The dissipation of chlorpyrifos (CP) and its hydrolytic metabolite 3,5,6-trichloro-2-pyridinol (TCP) in the soil is crucial for safe agriculture. However, there is still lacking relevant information about its dissipation under different vegetation for remediation purposes. In the present study, evaluation of dissipation of CP and TCP in non-planted and planted soil with different cultivars of three types of aromatic grass viz Cymbopogon martinii (Roxb. Wats), Cymbopogon flexuosus, and Chrysopogon zizaniodes (L.) Nash was examined in light of soil enzyme kinetics, microbial communities, and root exudation. Results revealed that the dissipation of CP was well-fitted into a single first-order exponential model (SFO). A significant reduction in the half-life (DT₅₀) of CP was observed in planted soil (30-63 days) than in non-planted soil (95 days). The presence of TCP in all soil samples was observed. The three types of the inhibitory effect of CP i.e. linear mixed inhibition (increase in enzyme-substrate affinity (Km) and decrease in enzyme pool (Vmax), un-competitive inhibition (decrease in Km and Vmax), and simple competitive inhibition were observed on soil enzymes involved in mineralization of carbon, nitrogen, phosphorus, and sulfur. The improvement in the enzyme pool (Vmax) was observed in planted soil. Streptomyces, Clostridium, Kaistobacter, Planctomyces, and Bacillus were the dominant genera in CP stress soil. CP contamination in soil demonstrated a reduction of richness in microbial diversity and enhancement of functional gene family related to cellular process, metabolism, genetic, and environmental information processing. Among all the cultivars, C. flexuosus cultivars demonstrated a higher dissipation rate of CP along with more root exudation.

Simultaneous determination of nine tyrosine kinase inhibitors in three complex biological matrices by using high-performance liquid chromatography-diode array detection combined with a second-order calibration method

An intelligent chemometric second-order calibration method called alternating trilinear decomposition- assisted multivariate curve resolution combined with high-performance liquid chromatography-diode array detection was used for the simultaneous quantification of nine tyrosine kinase inhibitors in three complex biological systems. The method allows simultaneous quantification of the components in different biological matrices without the need for cumbersome pre-treatment steps, complex elution conditions, and complete peak separation. Even with the varying time shift, severe peak overlap, and various unknown interferences, the proposed method can extract pure chromatographic and spectroscopic information for each analyte, while providing accurate qualitative and quantitative results of nine common tyrosine kinase inhibitors in three different biological matrices. All the drugs were eluted in 7 min. The results showed that the nine drugs in each matrix showed good linearity (r > 0.984) in the calibration range with a root mean square error of calibration less than 0.9 μg/mL. The average spiked recoveries of the target analytes were all in the range of 83.4-110.0%, with standard deviations less than 9.0%. Finally, the classical method was used to validate the proposed method. In comparison to the traditional method, the proposed strategy is accuracy, simultaneous, and interference-free.

Method validation and residue analysis of methoxyfenozide and metaflumizone in Chinese broccoli under field conditions by liquid chromatography with tandem mass spectrometry

Methoxyfenozide and metaflumizone are insecticides used on Chinese broccoli to prevent insects and increase yield. However, the residues are potentially harmful to the environment and consumers. In this study, the quick, easy, cheap, effective, rugged, safe method with high-performance liquid chromatography with tandem mass spectrometry was modified and validated for determination of methoxyfenozide and metaflumizone in Chinese broccoli. The clean-up efficiency of different sorbents including C₁₈ , primary secondary amine, graphitized carbon black, and carbon nanofiber was compared. Recoveries of the validated method were 71.8-94.6% with relative standard deviations of 1.5-3.2% and the limits of quantification were 0.01 and 0.005 mg/kg for methoxyfenozide and metaflumizone, respectively. A storage stability test showed almost no degradation of methoxyfenozide in Chinese broccoli, however, the degradation rate of metaflumizone was 22.9% after 10-wk storage at -20°C. In field trials in four producing regions, the dissipation of both methoxyfenozide and metaflumizone in Chinese broccoli was fast, with half-lives of only 1.0-5.1 and 0.7-2.5 days, respectively. Terminal residues after application of the two pesticides were all below 1.0 mg/kg after 5 days.

Modified dispersive solid-phase extraction and cleanup followed by GC-MS/MS analysis to quantify ultraviolet filters and synthetic musk compounds in soil samples

A simple method for the analysis of 13 synthetic musk compounds and six ultraviolet filters in soil samples was developed using a modified dispersive solid-phase methodology known as "Quick, Easy, Cheap, Effective, Rugged and Safe," followed by gas chromatography-triple quadrupole mass spectrometry. The methodology was validated by assessing linearity ranges, detection limits, precision, and accuracy. The method detection limit ranged between 0.01 and 10.00 ng/g dry weight and accuracy from 81 to 122%. A good precision was achieved, with relative standard deviation <10%. The applicability of the methodology was tested using different types of soils. Both synthetic musks and ultraviolet filters were detected in all soil samples. The most frequently detected compounds were benzophenone, octocrylene, 2-ethylhexyl 4-dimethylaminobenzoate, 2-ethylhexyl 4-methoxycinnamate, and galaxolide. Higher levels were detected for benzophenone (maximum value of 158 ng/g dry weight) and octocrylene (137 ng/g dry weight). In comparison with conventional techniques, this method uses lower amounts of solvents and sorbents, producing less waste ("greener" technique) and comparable performances. In addition, it presents as main advantages the simplicity, speed (short extraction/cleaning time), low cost, and minimum handling of extracts, which can minimize the possibility of samples cross-contamination.