Benzoic acid

Pyrrole, 4-carbomethoxybenzaldehyde, propionic acid, MnCl₂·4H₂O, tetrahydrofuran (THF), ZrOCl₂·8H₂O, benzoic acid, DMF and 4'6-diamidino-2-phenylindole (DAPI) were purchased from Sinopharm Chemical Reagent Co. Ltd (Beijing, China). RPMI 1640 and fetal bovine serum (FBS) were purchased from Gibco RBL/Life Technologies (Grand Island, NY, USA). SOSG was obtained from Thermo Fisher Scientific Inc. (Waltham, MA, USA). 2'7'-DCFH-DA was purchased from Sigma-Aldrich Company (St Louis, MO, USA). GSH assay kit, GPX assay kit and LPO assay kit were purchased from Nanjing Jiancheng Bioengineering Institute (Nanjing, China). All other regents were of analytical grade and used without any further purification.

Co(NO₃)₂·6H₂O, 2-methyl glyoxaline, dimethylformamide (DMF), toluene, benzyl alcohol, benzaldehyde were purchase from Shanghai Macklin Biochemical Co., Ltd. (Shanghai, China) N-hydroxyl phthalimide (NHPI), benzoic acid, 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), ethanol, and methanol were analytical grade and purchased from Sinopharm Chemical Reagent Co., Ltd (Tianjin, China). As an internal standard in the meteorological chromatographic analysis procedure, acetophenone were chromatographically pure and purchased from Shanghai Macklin Biochemical Co., Ltd (Shanghai, China). O₂ (99.99%) was provided by Maoming Deyuan Gas Company (Maoming, China).

Sodium alginate (99.9%, SA) was purchased from Shanghai Aibi Chemical Reagent Co., Ltd. (Shanghai, China). Copper sulfate anhydrous (CuSO₄, 99%) was purchased from Tianjin Regent Chemicals Co., Ltd. (Tianjin, China). Acetone (C₃H₆O, 99.9%), benzoic acid (C₇H₆O₂, 99.5%), zirconium(IV) oxychloride octahydrate (ZrOCl₂·8H₂O, 99%), and N, N-dimethylformamide (C₃H₇NO, 98%, DMF) were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Additionally, tetracids(4-carboxyphenyl) porphyrin (97%, H₄TCPP) was purchased from Shanghai bidepharmatech Co., Ltd. (Shanghai, China). Meanwhile, deionized water was used as the only water source in the whole experiment. All other chemical reagents were purchased commercially and used directly without further purification.

Hydrogen peroxide (H₂O₂, 30%), horseradish peroxidase (HRP, freeze-dried powder, >200 units/mg), N,N-diethyl-1,4-phenylenediammonium sulfate (DPD), L-tyrosine and L-phenylalanine were purchased from Aladdin (Shanghai, China). FeCl₃ and Nafion (10% in water) were purchased from Sigma-Aldrich (Shanghai, China). Tetrakis(4-carboxyphenyl)porphyrin (H₂TCPP) was purchased from TCI (Shanghai, China). Oxalic acid dehydrate was purchased from Mackin (Shanghai, China). ZrClO₂·8H₂O, benzoic acid, DMF, glucose, ascorbic acid, potassium dihydrogen phosphate, lithium carbonate, sodium phosphate monobasic dihydrate, sodium phosphate dibasic dodecahydrate, magnesium sulfate heptahydrate, and calcium chloride dehydrate were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). All the experimental water comes from the Milli-Q reference system (Millipore, America) unless stated otherwise.
Fishery product samples were Todarodes pacificus belonging to the family Ommastrephidae; Larimichthys polyactis belonging to the family Sciaenidae; Pennahia argentata belonging to the family Sciaenidae. The above three kinds of fresh fishery products were purchased in a local market (Xincheng Market, No. 95 Jindao Road, Dinghai District, Zhoushan 316021, China) and brought into the laboratory no later than 1 h in ice.