Before using carboxymethyl cellulose sodium, in order to ensure the performance of the product, it is necessary to measure it in advance. There are many methods for measuring CMC Na, and ashing method is one of the more frequently used methods. However, to ensure the accuracy of the measurement, specific knowledge can be learned from the following.

Transfer the precipitate into a 3 # glass sand core crucible, filter it, wash it several times with 80% ethanol (about 100ml), then wash it three times with 95% ethanol (about 60ml), absorb it, transfer it to an oven, and dry it at 105 ℃ until the mass is constant (about 3h). Cool and weigh it.

Pour the weighed dry pure carboxymethyl cellulose sodium into a dry 30ml ceramic crucible, slowly raise the temperature to 700 ℃ in a high-temperature furnace, maintain it for 30 minutes, and then take it out and cool it to room temperature.

Wet the burnt material with a small amount of distilled water, wash it several times with 100ml of distilled water, and transfer it to a 250ml beaker. Slowly heat it on an electric furnace until boiling, and keep it for 5 minutes. Add 2-3 drops of methyl red indicator and titrate with 0.1mol/L HCl standard solution to the endpoint.

From this, it can be concluded that the operating principle and method of carboxymethyl cellulose sodium ashing method should be strictly followed to ensure the accuracy of the product measurement and provide convenience for subsequent work.