Abstract The qualitative and quantitative sterol compositions of Sacha Inchi oil and Prinsepia oil were analysed by high-performance liquid chromatography (HPLC). The sterol compounds were mixed with citric acid, VE and other natural antioxidants and added to walnut oil, oxidation resistence was determined by the peroxide value and acid value. Gas chromatography/mass spectrometry (GC/MS) analysis was used to measure the fatty acids. The results showed that the content of β-sitosterol and stigmasterol in Sacha Inchi oil was 156.46 mg/100 g and 68.74 mg/100 g, Prinsepia oil was 176.26 mg/100 g and 38.29 mg/100 g, respectively. After 12 days of accelerated oxidation, the antioxidant effect was TBHQ > compound antioxidants > BHA > sterols of Sacha Inchi oil > sterols of Prinsepia oil > 30% Prinsepia oil > citric acid > VE. After accelerated oxidation for 48 h, the total unsaturated fatty acids in blank walnut oil showed a decreasing trend, and the antioxidant group inhibited the decrease in total unsaturated fatty acids. In conclusion, the antioxidant treatment groups can delay the oxidative cycle of walnut oil and effectively prolong the shelf life of walnut oil, and the compound groups can significantly enhance the antioxidant effect of walnut oil. This study provides a technical reference for the storage stability of walnut oil.

By rationally introducing aromatic carboxyl functionalized 1,8-naphthalimide, a water soluble fluorescent chemosensor (DA) was successfully synthesized. It could selectively and sensitively detect CN- in pure water via an intramolecular charge transfer to twisted intramolecular charge transfer (ICT-TICT) state change mechanism. The detection limit of the chemosensor DA to CN- was 1.38 × 10−8mol L-1 which was lower than 1.9 µmol L-1 (set by the World Health Organization (WHO)). Notably, DA displayed rapid response (about 1 s) for recognizing CN- in pure water. Furthermore, DA could be applied to monitoring CN- in tap water. Meanwhile, we prepared the test strips based on DA, which could rapidly and efficiently detect CN- in water.

The stimulatory effect of low concentrations of toxic chemicals on organismal metabolism, referred to as hormesis, has been found to be common in the widely used luminescence bioassay. This paper aims to study the hormesis phenomenon in both marine and freshwater luminescent bacteria, named Photobacterium phosphorem and Vibrio qinghaiensis. The effects of Cu (II), Zn (II), Cd (II) and Cr (VI) on luminescence of these two bacteria were studied for 0 to 75 minutes exposure by establishing dose- and time-response curves. A clear hormesis phenomenon was observed in all four testing metals at low concentrations under the condition of luminescence assays.