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Studies on nitenpyram determination and behavior within tea remain limited despite its widespread use as a neonicotinoid. An organic-saving analytical approach tailored for the detection of nitenpyram in tea was established. Nitenpyram was extracted by boiling water and cleaned up by Cleanert PCX solid-phase. The average recoveries were 75.1-94.5 %, with relative standard deviations (RSDs) of 0.7-8.6 % for saving 34.5-88.6 % organic solvent. The limits of quantification (LOQs) were 0.002 mg·kg -1 in fresh tea shoots, 0.005 mg·kg -1 in made tea, and 0.001 mg·L -1 in tea brew, satisfying the current minimum Maximum Residue Limit (MRL). Nitenpyram dissipated rapidly with half-lives of 1.2-1.4 days at the recommended dosage (27 g a.i. ha -1 ) in two locations. Remarkably, 20-110 % of nitenpyram was leached out from made tea in different brewing modes. This work provides insights into nitenpyram's rational application in tea cultivation and offers considerations to institutions tasked with unestablished MRLs in tea., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Microbial fuel cells (MFCs) have the dual advantage of mitigating Cr(Ⅵ) wastewater ecological threats while generating electricity. However, the low electron transfer efficiency and the limited enrichment of active electrogens are barriers to MFCs advancement. This study describes the synthesis of the TP-PDA-RGO@CC negative electrode using tea polyphenol as a reducing agent and polydopamine-doped graphene, significantly enhances the roughness and hydrophilicity of the anode. The charge transfer resistance was reduced by 94%, and the peak MFC power was 1375.80 mW m -2 . Under acidic conditions, the Cr(Ⅵ) reduction rate reached 92% within 24 h, with a 52% increase in coulombic efficiency. Biodiversity analysis shows that the TP-PDA-RGO@CC anode could enrich electrogens, thereby boosting the electron generation mechanism at the anode and enhancing the reduction efficiency of Cr(Ⅵ) in the cathode chamber. This work emphasizes high-performance anode materials for efficient pollutant removal, energy conversion, and biomass reuse., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Pymetrozine is a widely used pesticide. It is challenging to analyze and difficult to manage due to the large gap in its global maximum residue limits (MRLs) in tea. The development of a high-efficiency detection method for the evaluation of the transfer of residual pymetrozine from tea plantations to tea cups is therefore of prime significance., Results: An analytical method for the determination of pymetrozine residues in tea was established based on Cleanert PCX solid-phase extraction. The average recoveries were 72.2-93.7%, with relative standard deviations (RSDs) of less than 12%. The limits of quantification (LOQs) were 0.005 mg·kg -1 in fresh tea leaves and dry tea, and 0.00025 mg·L -1 in tea brew. Pymetrozine degraded rapidly in tea plants with a half-life (t 1/2 ) of 1.9 days in open tea plantations, and decreased by 9.4-23.7% in the green tea-processing procedure, which was concentration dependent. The residual pymetrozine levels in green tea collected at 6 and 21 days were below the MRLs in China and EU at a dosage of 30 g a.i. ha -1 , respectively. The leaching rates of pymetrozine from dry tea to tea brew were 58.7-96.3%. Hazard quotient (HQ) values of pymetrozine were significantly <100% when tea shoots were plucked in 6 days, which indicated a negligible risk to humans., Conclusion: This work allows the determination of residual pymetrozine in tea and illustrates a low intake risk with the use of pymetrozine in tea plantations. It could serve as reference for further regulation consideration for maximum residue limits (MRLs). © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Degradation and metabolism of chlorfluazuron and flonicamid from tea garden to cup were simultaneously investigated by a modified QuEChERS method coupled with UPLC-MS/MS quantification. The dissipation half-lives of chlorfluazuron, flonicamid, and total flonicamid (the sum of flonicamid and its metabolites TFNG, TFNA, and TFNA-AM) in fresh tea leaves during tea growth were 6.0 d, 4.8 d, and 8.1 d, respectively. TFNG and TFNA were generated during tea growth. After tea processing, the residues of chlorfluazuron, flonicamid, and its metabolites in black tea were higher than those in green tea. The average processing factors of chlorfluazuron, flonicamid, and total flonicamid in black tea were 2.54, 3.02, and 2.87, respectively, while in green tea they were 2.40, 2.93, and 2.79, respectively. TFNG, TFNA, and TFNA-AM were formed rapidly during the drying step. Considering the influence of water content at various processing steps, the average loss rates of chlorfluazuron, flonicamid, and total flonicamid residue from fresh tea leaves to black tea were 16.7%, 33.8%, and 20.7%, respectively, and 29.6%, 14.0% and 18.2%, respectively, in the case of green tea. The highest leaching rates of chlorfluazuron, flonicamid, and total flonicamid during tea brewing were 6.8%, 97.0%, and 97.4%, respectively, in black tea infusion, and 6.0%, 98.9%, and 98.6%, respectively, in green tea infusion. The metabolites, especially TFNG, had a higher leaching rate during tea brewing. The migration of chlorfluazuron from fresh leaves to tea infusion was low, and the migration of flonicamid was high. The RQc and RQa of chlorfluazuron and total flonicamid were less than 1. This result indicates that the potential dietary intake risk of chlorfluazuron from tea is negligible. However, the risk of total flonicamid intake is three times higher than that of chlorfluazuron. There is a potential risk of intake of flonicamid and its metabolites in tea for human consumption., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Background: A fuzzy analytic hierarchy process (AHP) is shown to be an effective methodology for multiple criteria decision-making from various heterogeneous data. Despite application of AHP to some decision-making problems in agriculture, research on AHP utilization for screening the safe use of pesticides for tea plantations based upon multiple criteria has not been reported. The overall safety chain from tea plantation to tea manufacture to tea cup after pesticides had been sprayed on a tea plantation was considered and the AHP network was constructed at two levels with two categories, tea-related parameters and pesticide toxicity. Seven criteria were selected as safety indexes, half-lives of pesticides on the tea plant (T 1/2 ), water solubility (Ws), vapor pressure (Vp), acceptable daily intake (ADI), acute oral lethal dose of pesticides to rat (LD 50 ), and ecotoxicity of pesticides including LD 50 to bees and LD 50 to aquatic organisms., Results: According to the AHP, water solubility was the most important factor in the evaluation pesticide safety for use on a tea plantation, followed by the half-lives of the pesticides on the tea plant and the acceptable daily intake. Combined with the scale of seven criteria and relative weight (W), 48 pesticides with an overall score (S) < 25 could be regarded as relatively safe compounds when applied in tea plantations., Conclusion: An AHP approach was suggested to evaluate the safe use of pesticides on tea plantations. This study provides a new idea for the evaluation of safety in beverage crops. © 2019 Society of Chemical Industry., (© 2019 Society of Chemical Industry.)

The percent transfer of pesticide residue from tea to infusion is an important factor that should be taken into consideration for setting realistic Maximum Residue Levels (MRLs) and risk assessment, as infusion prepared from dry tea is generally consumed, rather than the dry tea. The aim of this study is to investigate the inherent regularity of pesticides' transfer behavior, and to understand the effects of pesticide's physico-chemical parameters on its transfer behavior. A series of field trials, manufacturing and brewing experiments of 42 pesticides were conducted. Results indicated that transfer potential of a pesticide is related to its physical-chemical properties but not much to its type. Regression of transfer rate (TR) prediction model was logTR = 1.242 + 0.306log(Ws) (R 2  = 0.893). Thus, water solubility (Ws) can be used to predict the drinking safety of pesticides potentially introduced into tea plantation. Furthermore, as a case study on tea, this approach could also provide references for other beverage crops., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Penconazole is a typical triazole fungicide with wide use on fruits, vegetables, and tea plants to control powdery mildew. In the present study, an efficient graphite carbon black solid phase extraction (GCB-SPE) purification combined with chiral ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed for determination of penconazole enantiomers in different complex matrices, including grape, tea, soil, lotus root, lotus leaf, lotus seed and hulls. The method was then applied to investigate the enantioselective dissipation of penconazole enantiomers in a real field experiment of grape and soil. As a result, a satisfactory separation of penconazole enantiomers on a chiral Lux Cellulose-2 column (150 mm × 2 mm i.d., 3 µm) was obtained with 0.1% formic acid in methanol and 10 mmol L -1 ammonium acetate in water (75/25, v/v) as mobile phase at 0.25 mL min -1 . The enantiomer (+)-penconazole was firstly eluted, and (-)-penconazole was then eluted. The method showed reliable performances in linearity, recovery and precision, the recoveries of (+)-penconazole and (-)-penconazole in all of six matrices were between 70.5% and 121.0% with the relative standard deviations (RSDs) ranging from 0.8% to 23.6% at the low, medium and high spiked levels. The limits of quantitation (LOQs) of this method were lower than 0.0025 mg kg -1 in grape, soil and lotus root, 0.005 mg kg -1 in lotus leaf, lotus seed meat and lotus seed shell, and 0.0125 mg kg -1 in tea. Results of field trials indicated that (-)-penconazole degraded faster than its (+)-isomer in grape. While only a moderate stereoselectivity was observed in soil, with (-)-penconazole preferential degraded. The proposed method could be used to investigate enantioselective environmental behavior of penconazole enantiomers in complex matrices. And results in this study could provide useful information on realistic risk assessment of penconazole in grape., (Copyright © 2019 Elsevier Inc. All rights reserved.)

A chiral separation and residue determination method for diniconazole enantiomers in tea, apple, and grape was developed and validated by supercritical fluid chromatography coupled with quadrupole-time-of-flight mass spectrometry (SFC-Q-TOF/MS). The two diniconazole enantiomers were separated on a Chiral CCA column, and the chromatographic conditions (mobile phase proportion and modifier, column temperature, backpressure, and auxiliary solvent) were optimized. The optimal SFC-Q-TOF/MS conditions were selected as a mobile phase of CO 2 /isopropanol (IPA) (v/v, 96/4), flow rate at 2.0 mL/min, automated back pressure regulator (ABPR) at 2000 psi, column temperature at 25 ℃ and under electrospray ionization positive mode with the best auxiliary solvent of 2 mmol/L ammonium acetate in methanol/water (v/v, 1/1) at 0.20 mL/min flow rate. Residues in tea and fruit samples were extracted by acetonitrile/water (v/v, 4/1 for fruit and 2/1 for tea), purified by Cleanert TPT or Pesti-Carb solid phase extraction column, then analyzed by SFC-Q-TOF/MS with matrix-matched external standard quantification method. The elution order of diniconazole enantiomers on CCA column was R-(-)-diniconazole at first, and S-(+)-diniconazole at second. The standard curve concentration levels of R-(-)-diniconazole and S-(+)-diniconazole in samples ranged from 0.01 mg/L to 1.00 mg/L with the correlation coefficients greater than 0.99. The spiked recoveries of R-(-)-diniconazole and S-(+)-diniconazole in apple and grape at three levels of 0.005, 0.05 and 0.25 mg/kg were in the range of 69.8% to 102.1%, with relative standard deviations (RSDs) (n = 6) between 3.5% and 10.4%, and the limits of quantitation (LOQs) below 0.005 mg/kg. The spiked recoveries in black tea at three levels of 0.01, 0.10, and 0.50 mg/kg were in the range of 85.6% to 90.6%, with the RSDs (n = 6) ranging from 3.9% to 9.5%, and LOQ of 0.01 mg/kg. This residue analysis and determination method for diniconazole enantiomers in apple, grape and tea samples is convenient, reliable, and meets the residue analysis requirement. Also it is applicatied for the residue fates of R-(-)-diniconazole and S-(+)-diniconazole during the fresh tea leaves growing, green tea processing and black tea processing. The degradation half-times (DT 50 ) between R-(-)-diniconazole and S-(+)-diniconazole in the fresh tea leaves growing were 2.9 d and 3.1 d, respectively. The concentrations of R-(-)-diniconazole and S-(+)-diniconazole decreased gradually with time and on the 14th day after application were lower than 10% of the initial concentration. The average enantiomer fractions (EFs) of R-(-)-diniconazole and S-(+)-diniconazole at 2 h, 2, 5, 7, 10 and 14 d after application in fresh tea leaves were 0.505, 0.526, 0.523, 0.558, 0.453 and 0.489, respectively. This result is similar to the result of our last research for the enantiomers of cis-epoxiconazole-another triazole fungicide residues in fresh tea leaves. And in the whole black tea processing, 37.1%-49.3% and 35.9%-57.9% of R-(-)-diniconazole and S-(+)-diniconazole decreased, respectively. The total processing factors (PFs) of R-(-)-diniconazole and S-(+)-diniconazole for the black tea procedure were 0.507-0.629 and 0.421-0.641, respectively. The EFs of R-(-)-diniconazole and S-(+)-diniconazole in black tea processing ranged from 0.432 to 0.532. However, in the whole green tea processing, 22.3%-32.6% and 21.7%-40.3% of R-(-)-diniconazole and S-(+)-diniconazole decreased, respectively. The difference between black tea and green tea is nearly 15%, and in green tea is less decreased than in black tea. The total PFs of R-(-)-diniconazole and S-(+)-diniconazole for the green tea procedure were 0.674-0.777 and 0.597-0.783, respectively. The EFs of R-(-)-diniconazole and S-(+)-diniconazole in green tea processing ranged from 0.473 to 0.504. The PFs illustrated that for R-(-)-diniconazole and S-(+)-diniconazole decrease, the rolling and fermentation were the critical steps in black tea processing, and the rolling was the critical step in green tea processing, respectively., (Copyright © 2018 Elsevier B.V. All rights reserved.)

BACKGROUND: Afidopyropen is a novel biorational insecticide for controlling piercing pests with great potential for application in tea gardens that can form the metabolite M440I007 when utilized for crops. However, because of a lack of analytical method for afidopyropen and M440I007 in tea, there is no means of monitoring the residues. Therefore, method development, validation and simultaneous determination of afidopyropen and M440I007 in fresh tea leaves, dried tea and tea infusion is of prime significance. RESULTS: A TPT cartridge‐based method was developed for the solid phase extraction of afidopyropen and M440I007 from tea matrices. Extraction and clean‐up conditions, including the composition, volume and temperature of elutions, were optimized to achieve the best results. Both targets were extracted using water and acetonitrile, with a water:acetonitrile (v/v) ratio of 4:10 for fresh leaves and 8:10 for dried tea, which were then cleaned and analyzed using ultraperformance liquid chromatography‐tandem mass spectrometry. Both analytes demonstrated excellent linearity with a correlation coefficient above 0.998. The optimized analytical method offered limits of quantifications of 0.005, 0.005 and 0.002 mg kg−1 (converted to dried tea) in fresh tea shoots, dried tea and tea infusion for both targets, respectively. Average recoveries of afidopyropen and M440I007 ranged from 79.0% to 101.5%, with relative standard deviations ≤ 14.7%. CONCLUSION: The results showed that the method of determination for these insecticides in tea matrices was practical and efficient. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Alkylphenol ethoxylates (APEOs) represent a non-ionic surfactant widely used as adjuvants in pesticide formulation, which is considered to cause an endocrine-disrupting effect. In the current study, we established a detection method for the APEOs residue in tea based on solid-phase extraction (SPE) for the simultaneous analysis of nonylphenol ethoxylates (NPEOs) and octylphenol ethoxylates (OPEOs) by UPLC–MS/MS. In the spiked concentrations from 0.024 to 125.38 μg/kg for 36 monomers of APEOs (nEO = 3–20), the recoveries of APEOs range from 70.3–110.7% with RSD ≤ 16.9%, except for OPEO20 (61.8%) and NPEO20 (62.9%). The LOQs of OPEOs and NPEOs are 0.024–6.27 and 0.16–5.01 μg/kg, respectively. OPEOs and NPEOs are detected in 50 marketed tea samples with a total concentration of 0.057–12.94 and 0.30–215.89 µg/kg, respectively. The detection rate and the range of the monomers of NPEOs are generally higher than those of OPEOs. The current study provides a theoretical basis for the rational use of APEOs as adjuvants in commercial pesticide production. [ABSTRACT FROM AUTHOR]

An analytical method simultaneously detecting pesticide and its metabolites, especially with higher toxicity, was urgently needed for supervision and safety evaluation of agricultural products. In the present study, a modified QuEChERS method coupled with a ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for simultaneous determination of tolfenpyrad (TFP) and its metabolites in tea matrices (fresh tea shoots, green tea, black tea, green tea infusion and black tea infusion) was established. The method validation showed good linearity (correlation coefficients ≥ 0.9945), accuracy (recoveries in 75.38–109.90%), sensitivity (limits of quantification ≤ 0.05 mg kg−1), and precision (relative standard deviations ≤ 19.09%). The established method was then applied to detect 40 market samples, resulting in 60.0% positive rate of TFP, besides, two metabolites including PT-CA, which is more toxic than the parent TFP, and PT-OH were also detected in the samples with high TFP residue (≥0.048 mg kg−1). The method established in the present work was thus of significant importance in comprehensive monitoring and of TFP in tea products. [ABSTRACT FROM AUTHOR]

BACKGROUND Tea is one of the most popular drinks in the world. The growth of tea plant is inseparable from the control of pesticides on diseases and pests. Pyriproxyfen is used as a pesticide substitute to control insect pests in tea gardens, but little is known about its residue degradation. Here, we performed an integrative study of the degradation and metabolism of pyriproxyfen from the tea garden to the cup. RESULTS: The dissipation half‐life of pyriproxyfen during tea growth was 2.74 days, and five metabolites PYPAC, PYPA, DPH‐Pyr, 5′′‐OH‐Pyr, and 4′‐OH‐Pyr were generated. The total processing factors for pyriproxyfen in green tea and black tea were 2.41–2.83 and 2.77–3.70, respectively. The residues of pyriproxyfen and its metabolites were affected by different processing steps. The total leaching rates of pyriproxyfen from green tea and black tea into their infusions were 9.8–12.3% and 5.3–13.8%, respectively. The leaching rates of the five metabolites were higher than that of pyriproxyfen and increased the intake risk. CONCLUSION: To ensure safe consumption, the recommended maximum residue limit value of pyriproxyfen in tea can be set to 5 mg kg−1 and the pre‐harvest interval can be set to 5 days. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A reliable, simultaneous residue-analysis method for pyriproxyfen and its five metabolites in fresh tea leaves, green tea, black tea, green-tea infusion and black-tea infusion was developed and validated. The samples were extracted with acetonitrile, purified using a modified QuEChERs (quick, easy, cheap, effective, rugged and safe) method and determined using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS). The method was successfully calibrated in the range of 0.005–2.50 mg/L with correlation coefficients (r) equal to or above 0.9957. The limits of detection (LODs) were less than 0.002 mg/L. The average spiked recoveries of pyriproxyfen and its metabolites at four levels were 71.2~102.9% with relative standard deviations (RSDs) of 0.3~14.4%. The limits of quantification (LOQs) in fresh tea leaves, tea and tea infusion were 0.002 mg/kg, 0.005 mg/kg and 0.0002 mg/L, respectively. This proposed method was feasible and was applied to analyze the residues of pyriproxyfen and its five metabolites on real fresh tea leaf samples. The results indicated that the half-life (t1/2) of pyriproxyfen on fresh tea leaves was 2.48 d, and the five metabolites were detected on fresh tea leaves during field growth after application. [ABSTRACT FROM AUTHOR]

BACKGROUND Picoxystrobin is a new osmotic and systemic broad‐spectrum methoxyacrylate fungicide with a good control effect on tea anthracnose, so it has been proposed to spray picoxystrobin before the occurrence and onset of tea anthracnose during tea bud growth in order to protect them. However, there are few reports about the residue analysis method, field dissipation, terminal residue and risk assessment of picoxystrobin in tea. And there is no scientific and reasonable maximum residue limit of picoxystrobin in green tea. RESULTS: A rapid and sensitive analysis method for picoxystrobin residue in fresh tea leaf, green tea, tea infusion and soil was established by UPLC‐MS/MS. The spiked recoveries of picoxystrobin ranged from 73.1% to 111.0%, with relative standard deviations from 1.8% to 9.2%. The limits of quantitation were 20 μg kg−1 in green tea, 8 μg kg−1 in fresh tea leaves and soil and 0.16 μg kg−1 in tea infusion. The dissipation half‐lives of picoxystrobin in fresh tea leaf and soil were 2.7–6.8 and 2.5–14.4 days, respectively. And the maximum residue of picoxystrobin in green tea was 15.28 mg kg−1 with PHI at 10 days for terminal test. The total leaching rate of picoxystrobin during green tea brewing was lower than 35.8%. CONCLUSIONS: According to safety evaluation, the RQc and RQa values of picoxystrobin in tea after 5 to 14 days for the last application were significantly lower than 1. Therefore, the maximum residue limit value of picoxystrobin in tea that we suggest to set at 20 mg kg−1 can ensure the safety of tea for human drinking. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Oxathiapiprolin is the first chiral piperidinyl thiazole isoxazoline fungicide developed to control downy mildew and other diseases, and there were no prior reports on its enantiomeric residue. In this study, a modified quick, easy, cheap, effective, rugged, and safe extraction and purification method followed by ultra‐high performance liquid chromatography–tandem mass spectrometry determination was first developed and validated for the residue analysis of oxathiapiprolin enantiomers and its metabolite IN‐E8S72 in green tea and other crops. Oxathiapiprolin enantiomers and IN‐E8S72 were separated on a chiral Lux Cellulose‐3 column with the use of 0.1% formic acid in acetonitrile and 5 mmol/L ammonium acetate in water as mobile phases. IN‐E8S72 was eluted first, followed by (−)‐oxathiapiprolin, and then (+)‐oxathiapiprolin. The recoveries ranged from 53.3 to 125.3% with relative standard deviations ranging from 1.4 to 16.0%. The limits of quantification for (−)‐oxathiapiprolin and (+)‐oxathiapiprolin were 0.005 mg/kg in romaine lettuce, head cabbage, potato, grape, and garlic, 0.01 mg/kg in soybean and pea, and 0.025 mg/kg in green tea and dry pepper. The limits of quantification of IN‐E8S72 were twice those of (−)‐oxathiapiprolin. Screening results with real market samples indicated that there was no enantiomeric excess in the oxathiapiprolin residue in romaine lettuce. [ABSTRACT FROM AUTHOR]

BACKGROUND Methoxyfenozide possesses efficacy against a variety of lepidopteron pests, including the major pests in cauliflower and tea, so it is of great importance to generalize the practical use of methoxyfenozide in the field. RESULTS: An efficient method was developed and validated in both vegetable matrix and extract‐rich matrix (cauliflower and tea) using modified QuEChERS combined with UPLC/MS/MS analysis. The recoveries in cauliflower, made tea and tea shoots ranged from 94.5 to 108.0%, from 85.0 to 91.6% and from 77.3 to 82.0% respectively, with relative standard deviations (RSDs) below 17.3% in all cases. The field results showed that methoxyfenozide dissipated in cauliflower with half‐life (t1/2) at 2.5–3.5 days and in tea with t1/2 at 1.2 days. Combining the above experimental data and statistical food intake values, the risk quotient (RQ) values were significantly lower than 1. CONCLUSION: The quantification method of methoxyfenozide in cauliflower or tea has not been established until this study. The dissipation and dietary exposure risk assessment of methoxyfenozide in cauliflower and tea were investigated in the field. Methoxyfenozide dissipated rapidly in cauliflower despite different climates, and it dissipated faster in tea. The dietary risk of methoxyfenozide through cauliflower or tea was negligible to humans. This study not only provides guidance for the safe use of methoxyfenozide but also serves as a reference for the establishment of maximum residue limits (MRLs) in China. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

• Tea residue behavior of afidopyropen insecticide and its metabolite was studied. • Afidopyropen dissipated faster in tea during the rainy season than the dry season. • Low infusion rates of afidopyropen and metabolite M440I007 were noted. • Afidopyropen is recommended for pest control in tea gardens due to low health risk. Afidopyropen, a novel insecticide, is highly effective against piercing insects such as the tea leafhopper. The residual levels of afidopyropen and M440I007 in tea cultivation, processing, and brewing were studied. During tea cultivation, afidopyropen dissipated faster in fresh tea shoots in the rainy season (T 1/2 of 1.2–2.5 d) than that in the dry season (T 1/2 of 3.1–4.4 d); afidopyropen was metabolized into M440I007, the level of which peaked in 1 d, and degraded rapidly (over 90 %) afterward 3 d. The green tea processing steps had little effect on decreasing the afidopyropen residue (PF of 0.90–1.18). Low infusion rates of afidopyropen (16.7 %–17.7 %) and M440I007 (4.1 %–6.2 %) were observed from dry green tea to infusion; furthermore, the risk of ingesting afidopyropen from drinking tea was low, with the risk quotient values < 0.0001. This study can offer guidance on the rational application of afidopyropen in tea plants. [ABSTRACT FROM AUTHOR]

The degradation and metabolism of spinetoram in tea growth, processing and brewing were studied and analyzed by a modified QuEChERS coupled with UPLC-MS/MS method for the first time. The dissipation study showed that the half-life of spinetoram in fresh tea leaves was 0.70 d, and the metabolites N -formyl-XDE-175-J and N -demethyl-XDE-175-J were generated in tea growth. The degradation rates (DRs) of total spinetoram in green tea and black tea processing were 34.9%–57.8% and 36.9%–68.2%, and the transfer rates (TRs) were 5.1%–21.5% and 6.3%–27.7% from green tea and black tea into their infusion, respectively. Five days after spraying, the residue of spinetoram decreased more than 99% throughout the process from spraying to tea infusion, indicating that spinetoram has a lower residue amount in tea and tea infusion. The dietary risk assessment showed that the RQc and RQa were significantly less than 1, and the full dietary intake risk value was 8.78%. Thus, the MRL of spinetoram in tea can be set at 1 mg/kg with a pre-harvest interval (PHI) at 5 d to ensure safety for human consumption. • Spinetoram and its metabolites in different tea matrices were analyzed by a modified QuEChERS-UPLC-MS/MS method for the first time. • Residue degradation and metabolism of spinetoram in tea growing, processing, and brewing chains were studied, with >99% of residues decreasing from tea gardens to cups. • Spinetoram is suitable for usage in tea gardens, as it decreased rapidly in fresh tea leaves (t 1/2 = 0.70 d) and due to its low total dietary intake risk (<8.78%). [ABSTRACT FROM AUTHOR]