No abstract

Grapes are among the most popular fruits globally, and various fungicides are widely applied to grape crops. As such, the presence of multiple fungicide residues and dietary risks in grapes has become the focus of significant attention. In this study, an easy-to-implement and sensitive UPLC-MS/MS approach was developed to simultaneously determine pyraclostrobin, dimethomorph, cymoxanil, cyazofamid and its metabolite CCIM in grapes via QuEChERS. This approach achieved 78.1–106.0% recovery and a 0.01 mg kg–1 limit of quantitation (LOQ). Field trials revealed that these compounds had degradation half-lives ranging from 0.9 to 13.3 days. And their terminal residues ranging from < LOQ to 1.36 mg kg–1 were below the official maximum residue limit (MRL) in China. The short-term risk for each tested fungicide was below 54%. The long-term risk of individual chemicals ranged from 0.0086% to 3.1%, and their cumulative risk was 4.4%. Results indicated that the dietary risk of these fungicides in grapes was minor.

No abstract

Composite coatings synthesized by different morphologies of CeO 2 in supergravity devices are highly active in hydrogen evolution reactions (HERs). By adding CeO 2 nanoflakes (CeO 2 Nf) or CeO 2 nanorods (CeO 2 Nr), the change in the microstructures of composites becomes quite distinct. Moreover, most Ni-S alloys are attached on the surface of CeO 2 and roughen it compare with pure CeO 2 . In order to make the expression more concise, this paper uses M instead of Ni-S. At a current density of 10 mA/cm 2 , overpotentials of Ni-S/CeO 2 Nr (M-CeO 2 Nr) and Ni-S/CeO 2 Nf (M-CeO 2 Nf) are 200 mV and 180 mV respectively, which is lower than that of Ni-S (M-0) coating (240 mV). The exchange current density (j 0 ) values of M-CeO 2 Nf and M-CeO 2 Nr are 7.48 mA/cm 2 and 7.40 mA/cm 2 , respectively, which are higher than that of M-0 (6.39 mA/cm 2 ). Meanwhile, double-layer capacitances (C dl ) values of M-CeO 2 Nf (6.4 mF/cm 2 ) and M-CeO 2 Nr (6 mF/cm 2 ) are 21.3 times and 20 times of M-0 (0.3 mF/cm 2 ), respectively.