Determination of Ignition Residues of Organic Chemical Products

Warning: This standard does not mention all the safety issues related to the use of the standard.

1 Scope

This standard specifies a general method for the direct determination of ignition residues of organic butane products

The wood standard applies to the determination of the burning residue content of organic chemical products

2 Normative references

The clauses in the following documents become the clauses of this part after being quoted in this part

Preparation of preparations and products used in GB/T603-2002 chemical reagent test method (ISO6353-1; 1982, NEQ)

3 General rules

Unless otherwise specified, only reagents confirmed to be analytically pure are used in the analysis

The preparations and products used in the analysis are prepared in accordance with the provisions of GB/T603-2002 when other requirements are not specified

4 Method summary

The residual substance after carbonization and high-temperature burning of the sample is weighed with a balance to obtain the mass of the burning residue

5 Reagents

5.

5.

6 Instruments

6.

6.

6.

6.

7 Analysis steps

7.

7.

7.

7.
4 Place the crucible containing the sample on the electric furnace and slowly heat it until the sample is fully carbonized
.
Move the crucible into the high-temperature furnace and operate according to 6.
2
.

7.
5 For samples that are more difficult to burn, add (0.
5-1.
0) mL of nitric acid to the carbonized crucible to moisten the carbonized material, heat it on an electric furnace until the brown smoke disappears, and then move it into a high-temperature furnace and operate according to 6.
2
.

7.
6 In the same test: the same desiccator should be used, and the same number of crucibles should be placed in a constant amount each time
.
The cooling time of an empty crucible and a crucible with residue is the same
.

7.
7 The burning temperature should be selected from the following temperatures according to different products: 650℃, 750℃, 850℃
.

8 Result calculation

The mass fraction w of the burning residue, expressed in %, is calculated as follows:

Where:

m ₁ -the value of the mass of crucible plus residue, in grams (g);

m ₂ -the value of the mass of the crucible, in grams (g);

m—The value of the mass of the sample, in grams (g)
.

Take the arithmetic average of the two parallel determination results as the determination result
.

9 tolerance

When the mass fraction of the burning residue w≥20.
01%, the absolute difference between the two parallel determination results is not more than 10% of the arithmetic mean of the two determination values;

When the mass fraction of the burning residue w<0.
01%, the allowable difference of the two parallel determination results is specified in the product standard according to the index of the burning residue
.