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• Amino-containing MOFs MIL-125-NH 2 was designed as a new sorbent in d-SPE. • MIL-125-NH 2 enrich the target analytes directly to improve sensitivity. • Amino-containing MIL-125-NH 2 has good adsorption capacity. • The detection limits were lower than most of traditional methods. • MIL-125-NH 2 is recovered easily and reused at least 8 times. A simple, environmentally-friendly and reliable method was developed to simultaneously monitor the residue of methyl 1-naphthalene acetate, parathion-methyl, fenitrothion, bromophos and phenthoate in pomelo by using dispersive solid-phase extraction technique (d-SPE). In this method, these target analytes were captured by MIL-125-NH 2 and detected by GC–MS/MS. The key parameters of d-SPE were optimized by the single factor experiment. Under the optimized conditions, a good determination coefficient (R2 > 0.9922) and extraction recoveries (64.7–116.8%) are obtained. The limit of detections (0.03–1.07 ng/g) is lower than the MRLs in citrus fruits established by EU (10–15000 ng/g) and China (10–10000 ng/g). The precisions of intra-day and inter-day are 1.3–8.9% and 3.8–14.9%, respectively. In addition, the sorbent MIL-125-NH 2 is stable and can be reused at least eight times. These results prove the established method is efficient and reliable to detect the pesticide residues in pomelo. [ABSTRACT FROM AUTHOR]

Organophosphorus pesticides (OPPs) are among the most commonly used pesticides worldwide. However, these compounds pose a serious threat to aquatic environments. Here, thirty-seven pesticides and eight degradation products were determined in surface water samples from Tai Lake, East China, using a high-volume solid phase extraction technique (Hi-throat/Hi-volume SPE). Surface water was pumped in-situ through a portable sampler, and OPPs in the water retained on the Hi-volume SPE adsorption column, finally extracted for analysis. This technique efficiently reduced the detection limits to below 0.3 ng/L. In total, 40 out of 45 OPP congeners were detected, which far exceeded the amount of OPPs in previous studies. The total concentration of OPPs ranged between 101.4 and 1530 ng/L (median: 378.9 ng/L). Parathion exhibited the highest concentration (median: 112.0 ng/L), followed by paraoxon-methyl (median: 90.3 ng/L), as well as carbophenothion, fenthion, and mevinphos. Agricultural areas were more polluted than residential and industrial regions. However, degradation products persisted in residential and industrial waters. The ecological risks of OPPs in these areas were estimated based on the risk quotient index (RQ). Parathion, fenthion, carbophenothion, and tolclofos-methyl occurred at high-risk levels, and the levels of degradation products were also non-trivial. Our findings thus indicated that OPP degradation products pose a potential threat to natural environments and should therefore be closely monitored. [Display omitted] • Hi-throat/Hi-volume SPE technique was efficiently applied in assessing OPPs. • OPPs and degradation products detected in surface water of East China. • Degradation products persist in industrial and residential waters. • Parathion, fenthion, carbophenothion, and tolclofos methyl exhibited high risk. • Threating degradation products of OPPs needed further management. [ABSTRACT FROM AUTHOR]