Potassium tetroxalate dihydrate

white crystalline powder or colourless crystals

Potassium trihydrogen dioxalate dihydrat is used in metal polishing determination of pH. And it is also used in photography, marble grinding, and to remove ink stains.

A method of utilizing a solution of Oxalic acid potassium salt, dihydrate 99 % to react with calcium in the dentinal fluid forming an insoluble white precipitate of calcium oxalate which occludes the dentinal tubules causing decreased sensitivity, permeability and acid penetration of the dentin.

A method of producing potassium tetraoxalate by fermentation of Aspergillus niger, the method comprising the steps of:

a. Isolation and purification of Aspergillus niger: stem segments of wrinkled edge stone fir plant were selected, rinsed by running water for 2-3 hours→75% alcohol sterilization for 1-2min→0.01mol/L hydrochloric acid, 5% sodium hypochlorite, 2.4mmol/L citric acid were rinsed in turn→5% sodium hypochlorite was sterilized for 10-12min→ sterile water was Rinse 3-5 times→10% hydrogen peroxide disinfection 8-12min→aseptic water rinse 4-5 times→sterile blotting paper to absorb the surface water→inoculation on PDA plate→isolation, purification to obtain Aspergillus niger.

b, liquid fermentation culture of Aspergillus niger: per liter of PDA liquid medium, add sucrose 5 ~ 25g, pH adjusted to 4.7 ~ 6.4, aseptic condition, inoculation of Aspergillus niger spores, the amount of Aspergillus niger spores added to 1 liter of PDA culture medium plus 1% (by volume) of Aspergillus niger spores, spore concentration of 1 × 104 ~ 106cfu/mL, incubation temperature of 30 to 40 , speed of 120 ~ 150 rpm, the amount of air ventilation for the total volume of culture medium, that is, PDA culture medium, sucrose and Aspergillus niger spore inoculum amount of the sum of 30%, constant temperature fermentation culture for 72-100 hours, filtration of mycelium, the fermentation broth is concentrated to the total volume of the culture medium of 1/20 ~ 1/15, precipitation of crystals, ultrapure water washed 4 ~ 5 times, 40 ~ 50 drying, to get the tetraoxalic acid potassium salt. product.

Crystallise it from water below 50o. Dry it below 60o at 760mm. [See potassium oxalate above, Beilstein 2 IV 1823.]