Instruction manual of disodium chromotropic acid

海洋之神590登录入口1、 Basic information

Disodium chromotropic acid

海洋之神590登录入口Chinese alias: sodium chromotropic acid, sodium 1,8-dihydroxynaphthalene-3,6-disulfonate, sodium 4,5-dihydroxynaphthalene-2,7-disulfonate dihydrate

English Name: 4,5-dihydroxynaphthalene-2,7-disulfonic acid, disodium salt hydrate

CAS No.: 5808-22-0

海洋之神590登录入口EINECS No.: 204-972-9

Molecular formula: c10h6na2o8s2 · 2H2O

Molecular weight: 400.29

Melting point: 300 ℃

Boiling point: 176-177 ℃

海洋之神590登录入口Flash point: 164 ℃

2、 Physicochemical properties

海洋之神590登录入口Disodium chromotropic acid is white to gray, beige to light brown powder, easy to change color in contact with air, easily soluble in water, slightly soluble in ethanol, the solution is light brown, irritant

3、 Purpose

海洋之神590登录入口Biochemical research and organic synthesis. Spectrophotometric Determination of chromium, titanium and formaldehyde. Determination of chromium, mercury, silver, titanium, chlorate, formaldehyde, nitrate and nitrite. Determination of methylene dioxy by TLC. Determination of ethylene glycol in biomaterials.

4、 Technical index

Projects

Standard value

appearance

海洋之神590登录入口Light grey to light brown powder

Purity%

Above 98.5

Water soluble state

海洋之神590登录入口pass the test

Water content%

8% - 10%

Suitability of formaldehyde analysis

pass the test

海洋之神590登录入口5、 Detection method

1. Purity

Potentiometric titration

海洋之神590登录入口Weigh 0.6g (to 0.0001g) of the dried sample, put it into a 100ml beaker, add 50ml of pure water to dissolve the sample, and titrate it with 0.1mol/l sodium hydroxide standard solution by potentiometric titrator (for determination of titration method and end point, refer to GB / T 9725)

The consumption of 0.1mol/l NaOH is 1ml, which is equivalent to 0.04003g c10h6na2o8s2 · 2H2O

海洋之神590登录入口2. Solubility

Weigh 5.0g of disodium chromotropic acid sample, put it in a 250ml flask, add 100ml deionized water, and stir it in a water bath at 25 ℃ for 15min. The solution is uniform and transparent by visual inspection.

海洋之神590登录入口3. Water content

Karl Fischer titration

海洋之神590登录入口4. Formaldehyde analysis

海洋之神590登录入口Solution A: transfer 1ml of 35% formaldehyde aqueous solution, place it in 2000ml volumetric flask, and dilute it with deionized water.

Solution B: weigh 0.0500g of disodium chromotropic acid with analytical balance, put it in a 100ml volumetric flask, and dissolve it with 70% sulfuric acid.

Turn on the constant temperature water bath, set the water temperature at 65 ℃, after preheating, transfer 2ml of solution a and 50ml of solution B into a 250ml conical flask, and heat it in the water bath. After 10-15 minutes, the solution in the conical flask turns purple.

6、 Storage and transportation

海洋之神590登录入口1. It should be stored in a cool and ventilated warehouse. The temperature should not exceed 37 ° C. It should be kept away from light.

2. It should be stored separately from oxidants and edible chemicals, avoid mixed storage, and keep away from fire and heat source.

3. It is easy to change color in the air. It is forbidden to be exposed in the air for a long time.

4. Transport vehicles shall be equipped with corresponding varieties and quantities of fire fighting equipment and leakage emergency treatment equipment.

海洋之神590登录入口5. It is strictly forbidden to mix with oxidants, edible chemicals, etc.

6. During transportation, it should be protected from sun, rain and high temperature. During stopover, keep away from fire, heat source and high temperature area.

7、 First aid measures

Inhalation: if inhaled, move the patient to fresh air.

Skin contact: take off contaminated clothes and wash skin thoroughly with soapy water and water. If you feel unwell, see a doctor.

Eye clear contact: separate eyelids, wash with flowing water or normal saline. See a doctor immediately.

Ingestion: gargle, do not induce vomiting. See a doctor immediately.