(The reagent preparation in this reagent box is entirely derived from the national standard "Agrochemical Analysis Method") 01: phenol solution: Weigh 13.5 g of sodium hydroxide, 1.5 g of EDTA disodium salt, 2.5 g of sodium acetate, dissolve in about 200 ml of distilled water, add 22.5 g of phenol, dissolve and add distilled water to 500 ml. Brown bottles are kept in a cool place. 02: Sodium hypochlorite solution: Take 100ml of sodium hypochlorite with 5.25ml of the measuring tube and mix with 400ml distilled water. Store in a cool, brown bottle. 03: 4ppm, 8ppm ammonium nitrogen standard solution: (1) Weigh 0.4717g of anhydrous ammonium sulfate in distilled water, add 2ml of concentrated sulfuric acid, and add water to a volume of 1000ml. This liquid is a 100ppm standard solution. (2) Use a graduated pipette to draw 2 ml of 100 ppm standard solution and 4 ml respectively into a 50 ml volumetric flask. Distill with distilled water, the corresponding content is 4 ppm and 8 ppm. 04: Molybdenum sulphate solution: 126 ml of concentrated sulfuric acid was slowly added to a beaker containing 400 ml of distilled water, and stirring was continued, and cooling was performed. Another 10 g of ammonium molybdate was dissolved in a beaker containing 300 ml of distilled water and cooled. Weigh 0.5 grams of bismuth potassium tartrate in a beaker containing 100 ml of distilled water; slowly pour the sulfuric acid solution into the ammonium molybdate solution; pour the potassium antimony tartrate solution into a volume of 1 litre and store it in a brown bottle. in. 05:1ppm effective phosphorus standard solution: (1) Weigh 0.4390 grams of high-quality pure potassium dihydrogen phosphate dissolved in distilled water, add 2 ml of concentrated sulfuric acid, add water to volume to 1000 ml, this liquid is 100ppm standard solution. (2) Using a graduated pipette, draw 1 ml of the 100 ppm standard solution into a 100 ml volumetric flask and dilute to volume with distilled water. The content is 1 ppm. 06: Thymolphthalein solution: Weigh 0.05 g of thymolphthalein into 50 ml of 95% ethanol. 07: EDTA solution: Dissolve 10 g EDTA disodium salt in 100 ml of distilled water, add 5 drops of thymolphthalein solution, and then add sodium hydroxide solution to light blue, and store in a brown bottle. 08: sodium tetraphenylboron solution: 6 g of disodium hydrogen phosphate and 6 g of sodium tetraphenylborate are weighed, dissolved in 200 ml of distilled water, left overnight, and filtered in a brown bottle the next day. 09: Formaldehyde solution: Measure 100 ml of formaldehyde containing 37% reagent, add 5 drops of thymolphthalein solution, light blue with 8% sodium hydroxide solution, and store in a brown bottle. 10:20ppm available potassium standard solution: (1) Weigh 0.1907 g of high-quality pure potassium chloride dissolved in distilled water, add 2 ml of concentrated sulfuric acid, and add water to a volume of 1000 ml. This liquid is a 100 ppm standard solution. (2) Using a graduated pipette, draw 20 ml of 100 ppm standard solution into a 100 ml volumetric flask and dilute to volume with distilled water. The content is 20 ppm. 11: concentrated sulfuric acid: 98% (analytically pure). (Please bring your own) 12: Potassium dichromate solution: Weigh 39.23 grams of potassium dichromate (analytically pure), dissolve in 600 ml of water, dissolve and dilute to 1 litre with distilled water. 13: 0.5%-C standard solution: Weigh 1.376 g of glucose (chemically pure) in a 100 ml volumetric flask. After dissolving it with distilled water, add 1 ml of concentrated sulfuric acid. Add water to volume and shake. The standard solution contains carbon. 5 mg/ml. 14: Potassium chloride: 15 g (Analytical Pure). 15: Sodium bicarbonate: 8.4 g (Analytical Pure). 16: Sodium Nitrate: 17 g (Analytical Pure). 17: Ascorbic acid: 8 g (analytically pure). 18: Citric acid: 4 g (analytically pure). Hangzhou Top Instrument Co., Ltd. Room 806, Songdu Building, No. 69 Wangjiang Road, Hangzhou Phone 86062776 fax Industrial Sliding High Speed Door Stainless Steel Door SHENZHEN HONGFA AUTOMATIC DOOR CO., LTD , https://www.hongfahsrd.com
November 13, 2023