Development of QuEChERS coupled with UHPLC-MS/MS for simultaneous determination of eight neonicotinoid pesticides in breast milk.

A speedy and hypersensitive method was built to detect eight neonicotinoid insecticides (neonics) in breast milk by ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The breast milk was extracted with a mixture of acetonitrile and water and purified with primary secondary amine (PSA) and C18. The recovery of the method ranged from 74.3 to 105.9% with relative standard deviations (RSDs) of less than 10%, and the limit of detection ranged from 0.05 to 0.18 ng/mL. Among 32 samples obtained from women 1 month postpartum, thiamethoxam and imidacloprid were the most frequently detected neonics. Moreover, thiacloprid and imidaclothiz were not detected in any samples. The concentrations of neonics in breast milk ranged from 1.90 to 149.95 ng/mL. Considering the toxic effects on mammals and even humans, infants who are exposed to neonics through ingestion of breast milk should receive extensive attention in future studies.

Occurrence, distribution and potential risk to infants of neonicotinoids in breast milk: A case study in Hangzhou, China.

The pervasive use of neonicotinoid insecticides (neonics) has led to increasing concerns regarding the potential health risks associated with them. Breast milk is the main food source of infants, and thus, the presence of chemicals in breast milk has a greater impact on infant health. However, there have only been few reports regarding the presence of neonics in breast milk. Herein, eight neonics were detected in breast milk samples using ultraperformance liquid chromatography-mass spectrometry and their Pearson correlation was analyzed. The potential health risks of neonics to infants were assessed using the relative potency factor (RPF) method. The results revealed that neonics were widely detected in the breast milk samples from Hangzhou, with at least one neonics being detected in >94 % of the breast milk samples. The most frequently detected neonics included thiamethoxam (70.8 %) followed by imidacloprid (IMI) (62.0 %) and clothianidin (46.0 %). The residual concentrations of neonics in the breast milk samples ranged from

The stereoselective metabolic disruption of cypermethrin on rats by a sub-acute study based on metabolomics.

Due to the massive application of cypermethrin (CYP) for pest control in China, the adverse effects on non-target organisms have aroused great attention. However, comparative studies between its different stereoisomers remain scarce, especially for metabolism perturbations. Herein, the rats were administered α-CYP, ß-CYP, and θ-CYP by gavage at doses of 8.5, 29.2, and 25.0 mg/kg/day, respectively, for 28 consecutive days. By blood examination, significant changes in liver and renal function parameters were observed in rats exposed to all three CYPs. The stereoisomeric selectivity in metabolic disturbances was assessed based on a metabolomic strategy via multivariate analysis and pathway analysis. The results demonstrated that amino acid and glycolipid metabolism were disrupted in all CYP groups. Among them, the most significant changes in the metabolic phenotype were observed in the θ-CYP group, with 56 differential metabolites enriched in 9 differential metabolic pathways. At the same time, the endogenous metabolite trimethylamine oxide (TMAO), which is closely linked to the gut microbiota, was also significantly elevated in this group. Gender differences were found in α- and θ-CYP-exposed rats, with perturbations in amino acid and glucose metabolism of greater concern in females and lipid metabolism of greater concern in males. Overall, ß-CYP exhibited a lower risk of metabolic perturbations than α-CYP or θ-CYP, which helps to screen suitable agrochemical products for green agricultural development.

Organophosphate flame retardants in Hangzhou tap water system: Occurrence, distribution, and exposure risk assessment.

The usage of Organophosphorus flame retardants (OPFRs) is gradually increased as the ban on brominated flame retardants (BFRs) worldwide. The frequent accessibility of OPFRs in aquatic environment poses potential risk to human. Previous studies have concerned on surface water, while studies on tap water are limited. In this research, we aim to evaluate the removal efficiency of the tap water treatment process and investigate the exposure risk of OPFRs in tap water. Herein, we collected 14 samples from water source, 10 samples from water treatment plants and 47 from tap to analyze the concentrations and removal efficiency of OPFRs in Hangzhou tap water supply system. The results showed the concentrations of ∑OPFRs ranged from 9.25 to 224.74 ng/L in all samples, with Tris(1-chloro-2-propyl) Phosphate (TCPP), Tris(2-chloroethyl) phosphate (TCEP), Triphenyl phosphate (TPHP), and Tributyl phosphate (TBP) being the predominant compounds. Levels of the OPFRs had a 10.0 % - 50.4 % declination when compared samples after treatment with that before. The maximum exposure doses of ∑OPFRs via tap water for both adults and children were much lower than the reference dose (RfD). As a result, the hazard index (HI) and the carcinogenic risk (CR) pinpointed a negligible non-carcinogenic and carcinogenic risk for the residents. Even so, given the pervasive usage of OPFRs, the residual levels and the potential risk of OPFRs in watershed should be continuously concerned.