HG/T 4296-2012p-Nitrophenol (English PDF)

4.2 Material safety data sheet

According to GB/T 16483, the product, when leaving the factory, shall be provided with a detailed material safety data sheet. The material safety data sheet shall include the following contents:

a) hazard information of the product;

b) safe use method;

c) transportation and storage requirements;

d) protective measures;

e) emergency treatment measures, etc.

6.1 General provisions

Unless otherwise specified, use only reagents that are identified as analytical reagents and grade-3 water that is specified in GB/T 6682-2008. The standard titration solutions, preparations and products used in the test shall be prepared and calibrated according to the provisions of GB/T 601 and GB/T 603 unless otherwise specified. The determination of test results shall be carried out according to the comparison method of rounded-off values in 4.3.3 of GB/T 8170-2008.

6.2 Evaluation of appearance

Perform visual assessment under natural light.

6.3 Determination of p-nitrophenol content and free acid content

6.3.1 Reagents and solutions

a) sodium hydroxide standard titration solution: c (NaOH) = 0.1 mol/L;

b) bromophenol blue indicator solution: Weigh 0.1 g of bromophenol blue and dissolve it in 100 mL of ethanol solution (the volume ratio of ethanol and water is 20:80);

c) thymol blue-phenolphthalein mixed indicator solution: Weigh 0.12 g of thymol blue and 0.34 g of phenolphthalein and dissolve them in 100 mL of ethanol solution (the volume ratio of ethanol and water is 60:40).

6.3.2 Determination steps

Weigh 2.0 g (accurate to 0.000 2 g) of p-nitrophenol sample; dissolve it in about 100 mL of hot water (at about 80 °C); cool to room temperature; transfer to a 250 mL volumetric flask; add water to a constant volume.

Accurately pipette 50.00 mL of sample solution into a 250 mL beaker; add 50 mL of water; add 1 mL (about 20 drops) of bromophenol blue indicator solution; use sodium hydroxide standard titration solution to titrate until the solution turns purple as the end point; record the reading V1.

Accurately pipette 50.00 mL of sample solution into a 250 mL beaker; add 50 mL of water; add 4 ~ 5 drops of thymol blue-phenolphthalein mixed indicator solution; use sodium hydroxide standard titration solution to titrate, until the solution turns green and becomes orange as the end point; record the reading V2.

6.3.3 Result calculation

The free acid content is calculated by the mass fraction w1 of hydrochloric acid, and the value is expressed in %, and calculated according to Formula (1):

Where: c - the exact value of the concentration of sodium hydroxide standard titration solution, in moles per liter (mol/L);

V1 - the numerical value of the volume of sodium hydroxide standard titration solution consumed for titration of free acid, in milliliters (mL);

M1 - the molar mass value of hydrochloric acid, in grams per mole (g/mol), [M1(HCl)

7 - unknown; 8 - p-nitrophenol.

6.5 Determination of ash

Perform the determination according to the provisions of GB/T 21876-2008. The burning temperature is 700 °C ± 25 °C.

7.1 Inspection classification

All the inspection items listed in Table 1 in Chapter 3 of this Standard are type inspection items. Among them, except ash content in Table 1, the rest are exit-factory inspection items, which shall be inspected batch by batch. In the case of normal continuous production, the type inspection shall be carried out at least once a month. However, the type inspection is required in the following cases:

a) When the new product is initially finalized;

b) When the product is produced in a different place;

c) When there are major changes in the production formula, process and raw materials;

d) When production is resumed after three months of suspension;

e) When requested by the customer.

7.2 Exit-factory inspection

p-Nitrophenol shall be delivered only when it passes the inspection by the quality inspection department of the manufacturer, and is attached with a certificate of conformity. The manufacturer shall ensure that all p-nitrophenols shipped meet the requirements of this Standard.

7.3 Reinspection

If one of the indicators in the inspection results does not meet the requirements of this Standard, samples shall be taken from twice the amount of packaging for inspection again. Even if only one indicator fails to meet the requirements of this Standard in the re-inspection results, the entire batch of products shall be judged as unqualified. […]

8.1 Marking