(1) Add 800g of industrial Trometamol into 500ml of methanol aqueous solution, heat to 60°C and stir to dissolve, wherein, the methanol aqueous solution is prepared by mixing pure water and methanol in a volume ratio of 2:3;
(2) Add 8g of charcoal activated carbon to the solution, keep at 50°C for 30 minutes, filter while hot, and collect the filtrate;
(3) Concentrate the filtrate under reduced pressure, at a concentration temperature of 80°C, until crystallization occurs, let it cool, and the recovered methanol can be recycled;
(4) After the crystals were separated by suction filtration, rinsed twice with absolute ethanol, and dried at 50°C for 4 hours to obtain 680 g of finished product with a product purity of 100.03%.
Product inspection is based on Q/12HB4907-2013 standard inspection, among which,
(1) Water dissolution test
Weigh 1 g of sample, add 10 mL of water, and shake to dissolve. The solution should be clear and transparent.
(2) Ignition residue inspection
Weigh 5g of sample, put it in a crucible with constant weight, slowly heat for carbonization, cool, add 0.5mL of sulfuric acid, continue to heat until the sulfuric acid vapor is exhausted, and burn in a high-temperature furnace at 650±50℃ to constant weight. The mass of the residue shall not be greater than 1.0mg.
(3) Chloride inspection
Weigh 2g of sample, dissolve it in water and dilute to 20mL, add 2mL nitric acid solution (25%) and 1mL silver nitrate solution (17g/L), shake well, and let stand for 10min. The turbidity presented shall not be greater than the standard.
The standard is to take 0.01 mg of chloride impurity standard solution and dilute it to 20 mL, and process it in the same way as the sample solution of the same volume.
(4) Sulfate inspection
Weigh 0.5g sample, dissolve it in water and dilute to 20mL, add 1mL hydrochloric acid solution (20%) and 3mL barium chloride solution (250g/L), shake well, and let stand for 20min. The turbidity presented shall not be greater than the standard.
The standard is to take 0.02 mg of impurity sulfate standard solution and dilute it to 20 mL, and process it in the same way as the sample solution of the same volume.
(5) Heavy metal inspection
Weigh 4g of sample, dissolve in water, add acetic acid solution (30%) to neutralize and dilute to 40mL, take 30mL, add 0.2mL acetic acid solution (30%) and 10mL freshly prepared saturated hydrogen sulfide water, shake well. The shade should not be greater than the standard.
The standard is the remaining 10 mL of sample solution and 0.006 mg of impurity lead standard solution, diluted to 30 mL, and treated in the same way as the same volume of sample solution.
First, nitromethane and paraformaldehyde were weighed in a certain molar ratio of 1:3.3, and 93 g of paraformaldehyde was weighed and put into a 500ML four-necked flask, 85 g of methanol solvent and 0.3 g of KOH catalyst were added, and heated and stirred until completely dissolved, slowly dripping Add 55 g of nitromethane that has been weighed to carry out the condensation reaction, keep the reaction temperature at 40 to 55° C., and maintain the addition for 3 to 4 hours (at about 55° C.). After the reaction, put the condensed material into a 1L autoclave in one pot, add 350g methanol, 20g nickel catalyst, and check whether the autoclave is normal, and carry out hydrogen replacement in the autoclave, connect the power to start stirring, and introduce hydrogen to carry out reduction reaction, pressure Keep 2～3Mpa, the reaction temperature is controlled at 40～50℃, the hydrogenation is finished and maintained for 2～3 hours (insulation is about 50℃), the temperature rises at 60℃ and left for 1 hour, the conversion rate is 98%, and the material is discharged into a 1000ML four-necked flask, Add 5 g of activated carbon, stir for 1 hour (at about 50° C.), filter with a Buchner funnel, and crystallize 70 g of crude product by cooling. Take 70g of crude product into a 500ML four-neck flask, add 65g of deionized water and 5g of activated carbon, heat and stir, heat to 80°C for 1 hour, filter with a Buchner funnel, cool down and discharge, and dry to obtain 65g of finished product. Trometamol content 99.94%, absorbance (260nm) 0.043. The methanol content of the solution was 99%.
