Naclo

All reagents used in the experiment, including NaClO (Cl ≥ 7.5%), 30% H₂O₂, and Na₂S₂O₈ were purchased from Guangzhou Chemical Reagent Factory. Chemical reagents used in this work are all analytical grade, and the solutions are all prepared with deionized water. ZVI particle size for batch experiments was 0.15 mm, purchased from Shanghai A Latin (Shanghai). The ZVI particle size used in the column experiment was 1 mm, and purchased from Shandong Group Co., Ltd. Quartz sand (1 mm) obtained from Shilin Building Materials Company for dispersing the iron and adjusting the porosity of the column reactors. Prior to use, the sand was soaked in 10 mg P/L phosphate solution for 24 h. The phosphate stock solution (50 mg P/L) was prepared and diluted for the experiments. All glassware is soaked in 15% nitric acid before being used and washed with tap water and deionized water.

AOPPs were prepared in vitro by incubation of RSA (Sigma-Aldrich, USA) with 40 mM NaClO (Guangzhou Chemical Reagent Factory, Guangzhou, China) in the absence of free carbohydrates/amino acid/lipids to exclude the formation of advanced glycation end product-like structures as description (Guo et al., 2008 (link)). Prepared samples were dialyzed against phosphate-buffered saline (PBS) to remove hypochlorous acid and passed through a Detoxi-Gel column (Pierce, USA) to remove contaminated endotoxin. The level of endotoxin in the samples was measured with the amebocyte lysate assay kit (Sigma-Aldrich, USA) and were found to be below 0.025 EU/ml.
AOPPs content in the preparation, which was determined by the absorbance of the mixture of samples and acetic, was 66.1±4.7 mmol/mg protein. The components of advanced glycation end products were undetected in the prepared samples.