Determination of the dry residue after evaporation of volatile organic liquid on a water bath

Warning—Personnel using this standard should have practical experience in formal laboratory work

It should be noted that many products have potential hazards such as volatilization, flammability, reaction or poisoning; some solvents and chemical intermediates such as ethers and unsaturated substances may form peroxides during storage, and the presence of peroxides will cause Danger of strong explosion

In addition, all operations should be carried out in a cabinet with adequate ventilation

1 Scope

This part of GB/T6324 specifies a general test method for the determination of the dry residue of volatile organic chemical liquid products after evaporation on a water bath

This section applies to volatile organic liquids with evaporation residues greater than or equal to 10mg/kg [mass fraction of 0.

2 Normative references

The clauses in the following documents constitute the clauses of this standard through the reference of this part.

GB/T4472 General Rules for the Determination of Density and Relative Density of Chemical Products

3 Method summary

After evaporating the sample to dryness on a water bath: dry it to a constant weight in an oven at (110±2)°C

4 Instruments

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5 sampling

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6 Test method

Put the evaporating dish in the oven, heat it at (110±2)℃ for 2h, put it in a desiccator to cool to the ambient temperature, and weigh it to the nearest 0.

Pipette (100±0.

Wipe the outside of the evaporating dish with lens wiping paper, place it in an oven that has been thermostated to (110±2)℃ in advance, and heat it for 2h, then put it in a desiccator to cool to the ambient temperature, and weigh: accurate to 0.

7 Result calculation

The evaporation residue is calculated as mass fraction wa ₁ , and the value is expressed as %, calculated according to formula (1):

The evaporation residue is calculated as wa ₂ and the value is expressed in milligrams per liter (mg/L), calculated according to formula (2):

The evaporation residue is calculated as wa ₃ , and the value is expressed in milligrams per kilogram (mg/kg), calculated according to formula (3):

The evaporation residue is calculated as wa4, and the value is expressed in milligrams per 100 milliliters (mg/100mL), calculated according to formula (4):

wa ₄ = (mm ₀ )×1000.
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(4)

(1)(2)(3)(4) where:

m—the value of the mass of the evaporation residue plus the empty dish, in grams (g);

m _o -the value of the mass of the empty dish, in grams (g);

P—The density value of the sample at the test temperature, in grams per milliliter (g/mL) (measured in accordance with the provisions of GB/T4472);

V—The volume of the sample, in milliliters (mL)
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Related Links: Structural Features of Hazardous Organics (2)