1-Phenyl-3-methyl-5-pyrazolone (two)

4 sampling

Sampling is based on batches, and the production plant takes a batch of uniformly mixed products at one time

5 Test method

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

5.

Unless otherwise specified, only use reagents confirmed to be analytically pure and the tertiary water specified in GB/T6682

5.

Use visual evaluation under natural light

5.

5.

The standard titration solution of 1-phenyl-3-methyl-5-pyrazolone and sodium nitrite undergoes nitrosation reaction under acidic conditions, and the end point is indicated by starch-potassium iodide test paper

5.

a) Hydrochloric acid solution: 1+1

b) Sodium nitrite standard titration solution: c(NaNO ₂ )=0.

c) Starch-potassium iodide test paper

5.

Weigh 0.

5.

The content of 1-phenyl 3-methyl-5-pyrazolone is calculated by mass fraction w, and the value is expressed by (%), calculated according to formula (1):

Where:

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

M — The molar mass value of 1-phenyl-3-methyl-5-pyrazolone , in grams per mole (g/mol) [M(C ₁₀ H ₁₀ ON ₂ )=174.
20];

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

V ₀ -blank consumption of sodium nitrite standard titration solution volume value, the unit is milliliters (mL);

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

The calculation result is expressed to two decimal places
.

Allowable difference: The difference between the two parallel determination results is not more than 0.
3% (mass score), and the arithmetic mean is taken as the determination result
.

5.
4 Determination of the initial melting point of the dry product

According to GB/T617-1988 regulations
.
Take the sample measured in 5.
5 of this standard
.

5.
5 Determination of heating loss

Carry out in accordance with 3.
2 "Drying Method" in GB/T2386-2006
.
Weigh the sample amount from 5g to 10g, and the drying temperature is (80±2)℃
.

Allowable difference: the difference between two parallel determination results is not more than 0.
05% (mass fraction)
.

5.
6 Solubility in hydrochloric acid solution

5.
6.
1 Reagents and solutions

Hydrochloric acid solution: 1+6
.

5.
6.
2 Analysis steps

Weigh about 1g of the sample (accurate to 0.
01g), put it into a 100mL beaker, add 50mL of hydrochloric acid solution, and heat it to 70℃～80℃ to dissolve, and immediately observe the solubility of the solution
.

6 Inspection rules

6.
1 Inspection classification

All items specified in Table 1 in Chapter 3 of this standard are factory inspection items
.

6.
2 Factory inspection

1-Phenyl-3-methyl-5-pyrazolone should be inspected by the quality inspection department of the manufacturer
.
The manufacturer shall ensure that all the 1-phenyl-3-methyl-5-pyrazolones manufactured meet the requirements of this standard
.

6.
3 Reinspection

If one of the indicators in the inspection results does not meet the requirements of this standard, samples should be taken from twice the amount of packaging for inspection.
Even if only one indicator does not meet the requirements of this standard, the entire batch of products cannot be accepted.

.

7 signs, labels, packaging, transportation and storage

7.
1 Signs and labels

Each packaging container of 1-phenyl-3-methyl-5-pyrazolone should be coated with a firm and clear logo, indicating: product name, grade, registered trademark, net content, manufacturer name, and site , Standard number, batch number, production date
.
You can also print the batch number and production date on the label, and put it out of the plastic bag in the packaging container together with the product quality inspection certificate
.

7.
2 Packaging

1-Phenyl-3-methyl-5-pyrazolone is packed in woven bags or iron drums lined with plastic bags, and the net content of each bag (drum) is 25kg
.
Other packaging is determined through consultation with the user
.

7.
3 Transportation

Do not approach the fire source during transportation, and handle with care and avoid heavy pressure to avoid damage to the packaging
.

7.
4 Storage

1-Phenyl-3-methyl-5-pyrazolone should be stored in a clean, dry and ventilated warehouse, not close to the fire source, to prevent moisture and heat
.