HG/T 4296-2012 PDF in English

HG/T 4296-2012 (HG/T4296-2012, HGT 4296-2012, HGT4296-2012)
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HG/T4296-2012 (HGT4296-2012): PDF in English

HG/T 4296-2012
ICS 71.100.01;87.060.10
G 56
Record number: 36858-2012
ISSUED ON: MAY 24, 2012
Issued by: Ministry of Industry and Information Technology of the People’s
Republic of China.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Requirements ... 5
4 Safety information ... 5
5 Sampling ... 6
6 Test methods ... 6
7 Inspection rules ... 11
8 Marking, labeling, packaging, transportation and storage ... 11
WARNING – The personnel who uses this Standard shall have hands-on
experience in laboratory work. This Standard does not address all safety issues. It
is the user’s responsibility to take appropriate safety and health measures and
ensure compliance with the conditions stipulated in the relevant national laws and
1 Scope
This Standard specifies the requirements, safety information, sampling, test methods,
inspection rules, as well as marking, labeling, packaging, transportation and storage of
This Standard applies to the quality control of p-nitrophenol products.
Structural formula:
Molecular formula: C6H5NO3
Relative molecular mass: 139.11 (according to the international relative atomic mass in
CAS RN: 100-02-7
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition (including all amendments) applies to this document.
GB 190, Packing symbol of dangerous goods
GB/T 191, Packaging - Pictorial marking for handling of goods (mod GB/T 191-
2008, ISO 780:1997)
GB/T 601, Chemical reagent - Preparations of reference titration solutions
GB/T 603, Chemical reagent - Preparations of reagent solutions for use in test
methods (neq GB/T 603-2002, ISO 6353-1:1982)
to release toxic nitrogen oxide gas. This product can cause poisoning by inhalation,
ingestion or skin absorption. Necessary protective measures shall be taken during use
and handling, and strict attention shall be paid to safety.
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.
5 Sampling
Sampling shall be done in batches, and homogeneous products shall be taken as a batch
by the manufacturer. The number of samples per batch shall comply with the provisions
of 7.6 in GB/T 6678-2003. The packaging of the samples taken must be in good
conditions, and no foreign impurity is allowed to fall into the product during sampling.
When sampling, use a probe to take samples including upper, middle and lower parts.
The total amount of sample taken shall not be less than 500 g. After fully mixing the
samples taken, divide them into two clean, dry and well-sealed containers with labels
attached to them, indicating: product name, batch number, manufacturer name,
sampling date and location. Use one for inspection and the other one for future reference.
6 Test methods
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):
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)
= 36.45];
7 – unknown; 8 – p-nitrophenol.
Figure 1 – Schematic diagram of gas chromatogram of 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 Inspection rules
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
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 Marking, labeling, packaging, transportation and storage
8.1 Marking
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