Knowledge of human exposure to imidacloprid, the most extensively used insecticide, and para-hydroxybenzoic acid esters (parabens), the most extensively used preservative, is insufficient. In this study, 295 urine samples collected from subjects in rural and urban areas in China were analyzed for imidacloprid and four parabens (namely, methyl paraben, ethyl paraben, propyl paraben, and butyl paraben) as well as their major metabolites (namely, 6-chloronicotinic acid (6-ClNA) and para-hydroxybenzoic acid (p-HB)). Imidacloprid was detected in 100% of the urine samples from rural Chinese subjects and 95% of the urine samples from urban Chinese subjects. Concentrations of urinary imidacloprid detected in rural Chinese subjects (geometric mean (GM) = 0.18 ng/mL) were slightly higher than those detected in urban Chinese subjects (GM = 0.15 ng/mL) when the effect of pesticide spraying was excluded. However, concentrations of urinary imidacloprid detected in rural adults increased significantly in the subsequent days of pesticide spraying (GM = 0.62 ng/mL), which could return to the normal levels within 3 days. In contrast, concentrations of urinary parabens detected in rural Chinese subjects (GM = 6.90 ng/mL) were lower than that in urban Chinese subjects (GM = 30.5 ng/mL). In addition, the metabolism characteristics of imidacloprid to 6-ClNA and parabens to p-HB were discussed preliminarily.

Three nanocopper/low-density polyethylene (LDPE) composite films were tested in food simulants (3% acetic acid and 10% ethanol) and real food matrices (rice vinegar, bottled water and Chinese liquor) to explore the behaviours of copper migration using ICP-OES and GFAAS. The effects of exposure time, temperature, nanocopper concentration and contact media on the release of copper from nanocopper/LDPE composite films were studied. It was shown that the migration of copper into 10% ethanol was much less than that into 3% acetic acid at the same conditions. With the increase of nanocopper concentration, exposure time and temperature, the release of copper increased. Copper migration does not appear to be significant in the case of bottled water and Chinese liquor compared with rice vinegar with a maximum value of 0.54 μg mL for the CF-0.25# bags at 70°C for 2 h. The presence and morphology of copper nanoparticles in the films and the topographical changes of the films were confirmed by field emission scanning electron microscope (FE-SEM) and atomic force microscope (AFM). In this manner, copper nanoparticles of different morphologies, sizes and distribution were found, and samples with higher nanocopper concentration had a more irregular topography. In the case of Fourier transform infrared spectroscopy (FTIR), no chemical bonds formed between copper nanoparticles and LDPE. Copper nanoparticles were just as physically dispersed in LDPE.

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The creation of porous photothermal materials with high solar absorption and conversion efficiency is essential for the fabrication of efficient solar-driven interfacial evaporation devices. Herein, we demonstrate a strategy for scalable fabrication of solar steam generators based on hyper-cross-linked polymers (HCPs) in situ doped with carbon black (named C-[BzMim]Cl-co-PhH and C-[BzPy]Br-co-PhH). The monolithic HCPs composites consist of a hyper-cross-linked polymer skeleton and randomly distributed carbon black particles, which take advantage of both highly abundant porosity of HCPs and excellent light absorption of carbon black to create solar steam generators in a facile one-step preparation. By combining with their good thermal insulation (C-[BzMim]Cl-co-PhH 0.168 W m −1 K −1 and C-[BzPy]Br-co-PhH 0.123 W m −1 K −1 ) in wet conditions, the HCPs composites show high photothermal conversion performance with efficiencies of 85.2% and 88.4% for C-[BzMim]Cl-co-PhH and C-[BzPy]Br-co-PhH under 1 sun illumination, respectively. Moreover, the HCPs composites also exhibit excellent salt-resistance performance in solar steam generation (SSG), and the purified water can be used as domestic water. On the basis of such a simple and scalable fabrication approach as well as desired SSG performance, it is suggested that the HCPs composites may have great potentials as promising solar steam generators for real applications.

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