Industrial Acrylonitrile—Determination of Acidity, pH and Titration (3)

7 sampling

Take samples according to GB/T3723, GB/T6678GB/T6680

8 Analysis steps

8.

Note: The nitrogen flow rate is (200～500) mL/min

8.

8.

9 Presentation of analysis results

9.

The acidity is calculated as the mass fraction w of acetic acid , and the value is expressed in %, calculated according to formula (1):

Where:

V— The value of the volume of the standard titration solution of sodium hydroxide and isopropanol consumed by the sample , in milliliters (mL);

c—The exact value of the concentration of sodium hydroxide isopropanol standard titration solution, the unit is moles per liter (mol/L);

P—The value of the density of the sample, in grams per milliliter (g/mL);

0.

9.

The titration value Vy, expressed in mL, is calculated according to formula (2):

V _y =c/c _o ×V.

Where:

c— The actual concentration of sulfuric acid standard titration solution, the unit is moles per liter (mol/L);

co—Theoretical concentration of sulfuric acid standard titration solution, the value is 0.

V—The volume of the sample consumed by the standard titration solution of sulfuric acid, in milliliters (mL)

9.

Take the arithmetic average of the two repeated determination results as the analysis result.

10 Repeatability

In the same laboratory, the absolute difference between the two independent test results obtained by the same operator using the same equipment, using the same test method, and testing the same object under test independently in a short period of time should not exceed the following repetitions Limit (r) [provided that the repeatability limit (r) does not exceed 5%]:

Titration value: not more than 0.

11 Report

The report should include the following:

a) All information about the sample, such as the name of the sample, batch number, sampling point, sampling date, time, etc.
;

b) Number of this part;

c) analysis results,

d) Details and descriptions of any abnormal phenomena observed during the measurement,

e) the name of the analyst and analysis date
.

Related links: Industrial Acrylonitrile—Determination of Acidity, pH and Titration (2)