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An efficient PCN-224/graphene aerogel modified silica (PCN-224/GA@Sil)-based extraction method was established for monitoring the degradation process of two organophosphorus pesticides (OPPs) in juice. PCN-224/GA@Sil exhibited higher surface area (307.35 m 2 g -1 ) than graphene oxide modified silica (254.09 m 2 g -1 ). The introduction of PCN-224 endowed the sorbent with excellent adsorption specificity towards OPPs due to the ZrˑˑˑS/O coordination bond. PCN-224 exhibited relatively higher theoretical adsorption energies of PCN-224 towards fenitrothion and fenthion were 0.68 eV and -0.31 eV. The established PCN-224/GA@Sil-HPLC method showed the linearity of 0.2-500 μg L -1 for analytes. The matrix effects in juice were 9.68 % and 3.61 % for fenitrothion and fenthion. Finally, it was used for the sample pretreatment of juice preventing interference from food matrices to monitor the degradation of two OPPs. A combination method of ultrasound and xenon lamp was adopted to degrade fenitrothion and fenthion displaying the synergistic effect (SE=2.12, 1.39)., 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 B.V. All rights reserved.)

Absolute second-order rate constants for hydroxyl radical (HO) reaction with four organophosphorus pesticides, malathion, parathion, fenthion and ethion, and a suite of model compounds of structure (EtO) 2 P(S)-X (where X = Cl, F, SH, SEt, OCH 2 CF 3 , OEt, NH 2 , and CH 3 ) were measured using electron pulse radiolysis and transient absorption techniques. Specific values were determined for these four pesticides as k = (3.89 ± 0.28) x 10 9 , (2.20 ± 0.15) x 10 9 , (2.02 ± 0.15) x 10 9 and (2.93 ± 0.10) x 10 9  M -1  s -1 , respectively, at 20 ± 2 °C. The corresponding Brönsted plot for all these compounds demonstrated that the HO oxidation reaction mechanism for the pesticides was consistent with the model compounds, attributed to initial HO-adduct formation at the P(S) moiety. For malathion, steady-state 60 Co radiolysis and 31 P NMR analyses showed that hydroxyl radical-induced oxidation produces the far more potent isomalathion, but only with an efficiency of 4.9 ± 0.3%. Analogous kinetic measurements for the hydrated electron induced reduction of these pesticides gave specific rate constants of k = (3.38 ± 0.14) x 10 9 , (1.38 ± 0.10) x 10 9 , (1.19 ± 0.12) x 10 9 and (1.20 ± 0.06) x 10 9  M -1  s -1 , respectively, for malathion, parathion, fenthion and ethion. Model compound measurements again supported a single reduction reaction mechanism, proposed to be electron addition at the PS bond to form the radical anion. These results demonstrate, for the first time, that the radical-based treatment of organophosphorus contaminated waters may present a potential toxicological risk if advanced oxidative processes are used., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Five haptens with different spacer-arm attachment sites on the structure of the organophosphorus insecticide fenthion were designed and synthesized. All of the haptens were conjugated with ovalbumin (OVA) for the coating antigen, and three haptens containing all or most of the structure of fenthion were conjugated with bovine serum albumin (BSA) for the immunogen. Six polyclonal antisera were raised against the three BSA conjugates, and 30 antibody/coating conjugate combinations were selected for studies of assay sensitivity and specificity for fenthion. The study revealed the best combination with high sensitivity (I50 of 0.08 ng mL(-1)) and high assay specificity, which indicated that when structural difference between the analyte and an immunizing hapten is less than that between a coating hapten and the immunizing hapten, a high sensitive enzyme-linked immunosorbent assay (ELISA) in the heterologous system may stand a good chance to be developed. The immunity results showed that heterology in the hapten spacer-arm attachment site of the immunogen could achieve a remarkable improvement in the quantity, sensitivity, and/or specificity of antibody, and that the moiety of an analyte, which is the same as the moiety near/on the immunizing spacer-arm hapten attachment site, contributes greatly to the interaction of antibody and hapten.