Formic acid for industrial use (5)

5.

5.

Weigh about 20g laboratory sample, accurate to 0.

5.

The mass fraction of iron w ₂ , the value is expressed in %, calculated according to formula (2):

Where:

m ₁ —Check the standard curve to get the value of iron mass, the unit is milligram (mg);

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

Take the arithmetic mean of the two parallel determination results as the report result, and the absolute difference between the two parallel determination results shall not be greater than 20% of the arithmetic mean of the two determination values

5.

5.

Weigh about 40g of laboratory samples, accurate to 0.

5.

The mass fraction of evaporation residue w ₃ , the value is expressed in %, calculated according to formula (3):

Where:

m ₂ —The value of the mass of the quartz evaporating dish, in grams (g);

m ₃ ——The value of the mass of the quartz evaporating dish and the evaporation residue: the unit is grams (g);

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

Take the arithmetic mean of the two parallel determination results as the report result, and the absolute difference between the two parallel determination results shall not be greater than 20% of the arithmetic mean of the internal determination values

6 Inspection rules

6.

6.

a) Name of manufacturer:

b) Product name;

c) Product grade;

d) Production date or batch number;

e) Net content;

f) standard number and the like
.

6.
3 Under the conditions of the same raw materials and technology, the actual batch of continuous production of products is one batch, and the time for several production batches to form an inspection batch usually does not exceed 24 hours
.

6.
4 The sampling of industrial formic acid shall be carried out in accordance with the provisions of GB/T3723, GB/T6678 and GB/T6680
.
Use a glass sampler for sampling, and the total amount of samples collected shall not be less than 800 mL
.
After mixing the samples evenly, put them into two clean, dry thin-neck bottles with ground stoppers, label them and indicate: product name, batch number, sampling date, and sampler's name
.
The bottle is used for analysis and inspection, and the other bottle is kept for future reference
.

6.
5 The test result is judged according to the rounding value comparison method in GB/T8170
.
If one of the indicators in the inspection results does not meet the requirements of this standard, the barreled product shall be re-sampled from twice the volume of the packaging unit for inspection, and the canned product shall be re-sampled at multiple points for inspection
.
Even if only one index does not meet the requirements of this standard as a result of the re-inspection, the whole batch of products is unqualified
.