(1) the product of about 10mg, set a test tube, add water, and lml 2ml sulfuric acid, mix and let cool dissolve slowly along the wall add ferrous sulfate test solution 3ml, make into two liquid layers, nitric acid, then interface It was brown. (2) In the determination of the chromatogram records of the test solution peak retention time should be consistent with the reference solution peak retention time. (3) The product of the infrared light absorption spectrum with the control map (spectral set 473 Figure) consistent. [Check] nitrate to take this product 0.25g, add water, 5ml, shake for 5 minutes, filtered, and the filtrate added to a test tube 5ml sulfuric acid, mix and let cool slowly along the wall add ferrous sulfate test solution 5ml, so into two liquid layers, then the interface may not be immediately noticeable brown. Related substances to take this product, add the mobile phase ultrasound to dissolve and quantitative dilution made per lml of the solution containing about lmg of potassium nitrate prices, as the test solution; another Precision Weigh 2 - mononitrate isosorbide dinitrate reference and isosorbide dinitrate reference standard, accurately weighed, dissolved in mobile phase and quantitative dilution made about each lml each containing 0.5mg of the mixed solution, the precise amount of lml, set 100ml flask, then added for precision test solution lml, with the mobile phase and dilute to the mark, shake, as the control solution. According to Gao performance liquid chromatography (Appendix V D) test. Octadecylsilane bonded silica as a filler; methanol - water (25: 75) as mobile phase; detection wavelength was 210nm. Take control solution 20μl, into the liquid chromatograph, nitric acid droplets, adjust the sensitivity so that isosorbide dinitrate peak height of about 20% of full scale, 2-isosorbide dinitrate and isosorbide peak pear ester peak separation should be greater than 2.0. First the reactor and the cooling chamber are sequentially connected with a glass tube (the order is: reactor, cooling chamber, cooling chamber, an acid outlet.), Is added to the reaction concentrated sulfuric acid, dilute nitric acid was added, stirred for several minutes to mix (proportion 1/1), mixed acid should not exceed 1/2 of the reactor cover cap. After completion of the addition began to slowly heating, when the temperature reaches 86 degrees, nitric acid gas is distilled out, after the gas into the cooling chamber to condense into nitric acid flowing from the mouth, you can get 90% or more of the concentrated nitric acid. If not enough pure potassium nitrate manufacturer, will once again reflect the nitric acid process in accordance with the above method, you can get more than 99% of nitric acid, and pay attention before adding sulfuric acid plus nitric acid, pay attention to temperature control, because when the concentration of nitric acid already high, a mixture of both temperature rises rapidly. Where the sale of nitric acid | nitric acid | Zhengzhou Longda Chemical (Views) provided by the Zhengzhou Longda Chemical Products Limited. Road Zhiyuan, temper forward. Zhengzhou Longda Chemical Products Co., Ltd. (www.longdahuagong.com/) aims to become and you win symbiosis, strategic partners to move forward, more determined to become the most influential of inorganic acid companies, and you leap together to success !