What Is Calcium Oxalate?

Calcium oxalate, CaC2O4. The molecular weight is 128.10. The density is 2.20. Calcium oxalate is a white crystalline powder. Insoluble in water, acetic acid, soluble in concentrated hydrochloric acid or concentrated nitric acid. It turns into calcium carbonate or calcium oxide on burning. ^[1]

CAS number: 563-72-4

MDL number: MFCD00012474

EINECS number: 209-260-1 ^[2]

1. Properties: Anhydrous calcium oxalate is a colorless cubic crystal.

2. Relative density: 2.2.

3. Solubility: Insoluble in water, soluble in hydrochloric acid and nitric acid. In 100 g of water, 0.67 mg (13 ° C) and 1.4 mg (95 ° C) of calcium oxalate can be dissolved. ^[2]

1. Reference value for calculation of hydrophobic parameters (XlogP): None

2. Number of hydrogen-bonded donors: 0

3. Number of hydrogen bond acceptors: 4

4. Number of rotatable chemical bonds: 0

5. Number of tautomers: none

6. Topological molecular polar surface area: 80.3

7, the number of heavy atoms: 7

8. Surface charge: 0

9. Complexity: 60.5

10. Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. Uncertain number of atomic stereocenters: 0

13. Determine the number of chemical bond stereocenters: 0

14. Uncertain number of chemical bond stereocenters: 0

15. Number of covalent bond units: 2 ^[2]

A calcium chloride aqueous solution and an oxalic acid aqueous solution are co-thermally reacted to obtain calcium oxalate monohydrate, which is then dried in a hot air flow to a constant weight to obtain anhydrous calcium oxalate. A dilute aqueous solution of refined calcium chloride and an oxalic acid aqueous solution are co-thermally reacted. The precipitate is dissolved in hot hydrochloric acid, and ammonia water is added for reprecipitation. The precipitate is collected by filtration, washed with hot water, and dried at 105 ° C to obtain monohydrate. Calcium oxalate. Preparation of calcium oxalate monohydrate: Add a slight excess of 0.25mol / L calcium chloride aqueous solution to 1L of 0.25mol / L sodium oxalate aqueous solution (containing 5% hydrochloric acid) at room temperature. It was kept at for two days, and stirred at room temperature for one week. The precipitate was collected with a glass sand funnel, washed with 1% hydrochloric acid, and then washed thoroughly with water until the filtrate no longer had chloride ions. The precipitate was then placed in water and stirred for three weeks. The precipitate was collected by filtration and thoroughly washed with water, and then dried to constant weight at 40 ° C. The prepared calcium oxalate monohydrate is dried in a dry air flow at 250 ° C. to constant weight, thereby obtaining anhydrous calcium oxalate. ^[3]

It is used as an analytical reagent, as a carrier when separating rare metals, and also used in the preparation of oxalate. ^[2]

Calcium oxalate stones are five

Calcium oxalate stones: Low calcium and low oxalic acid diet should be used. Eat less milk and dairy products, soy products, meat, animal offal (such as liver, heart, kidney, intestines, etc.), but also chocolate, strong tea, sesame sauce, egg yolk, shiitake mushrooms, spinach, shrimp skin, radish, cocoa, celery, potatoes Wait. It was found that cellulose in food can reduce the formation of urinary calcium. For example, wheat bran bread and rice bran in wheat bran food also have the same effect. It is effective for recurrent high calcium urinary stones. The deficiency of vitamin B1 and vitamin B6 increases uric acid and should be increased. Foods containing such vitamins, such as cereals, dried fruits, hard fruits, etc.

(1) Drink more boiled water and drink more water to dilute the urine, the concentration of calcium ions and oxalate will decrease, and calcium oxalate stones cannot be formed. Studies have shown that a 50% increase in urine output can reduce the incidence of kidney stones by 86%.

(2) Reasonable calcium supplementation, especially those who have calcium supplementation on their diets often talk about calcium discoloration. They mistakenly believe that the culprit of kidney stones is calcium, but in fact, patients with kidney stones also need calcium supplementation. The medical profession explains from two different perspectives why patients with kidney stones need calcium supplementation.

Calcium supplementation can combine with the oxalic acid contained in vegetables in the gastrointestinal tract to form insoluble calcium oxalate, which is excreted with feces, which reduces part of the oxalic acid absorbed by the stomach and the kidneys, thereby reducing the chance of forming kidney stones.

(3) Limiting intake of sugars A recent study by American scientists showed that the intake of high-sugar foods can increase the chance of kidney stones, so pay attention to eating less sweets.

(4) Eat less

(1) Citrate Citrate is important for the formation of naturally occurring stones in urine

Calcium oxalate crystals: The formation of calcium oxalate crystals is considered to have a detoxifying effect, that is, a large amount of oxalic acid that is toxic to plants is neutralized by calcium. In organs, as tissues age, calcium oxalate crystals increase. Calcium oxalate is often colorless and transparent crystals, and is distributed in different forms.

S26In case of contact with eyes, rinse immediately with plenty of water and seek medical advice.

After accidental contact with eyes, rinse immediately with plenty of water and seek medical advice.

S37 / 39Wear suitable gloves and eye / face protection

Wear appropriate gloves and goggles or a mask.

S24 / 25 Avoid contact with skin and eyes.

Avoid contact with skin and eyes.

Risk term

R20 / 21/22 Harmful by inhalation, in contact with skin and if swallowed.

Harmful by inhalation, in contact with skin and if swallowed.

R36 / 37 / 38Irritating to eyes, respiratory system and skin.

Irritation of eyes, respiratory system and skin.

R21 / 22 Harmful in contact with skin and if swallowed.