GB/T 603-2023Chemical reagent - Preparations of reagent solutions for use in test methods (English PDF)

Foreword

This document was issued on 6 August 2023 by the State Administration for Market Regulation; Standardization Administration of the PRC and takes effect on 1 March 2024.

It is a GB/T standard: recommended rather than compulsory, but it is the text a Chinese reviewer applies when assessing a submission.

1 Scope

GB/T 603-2023 covers the preparations and products a laboratory has to make up itself before it can run the test methods for chemical reagents — the general provisions that fix the grade of reagent allowed, and the preparation methods themselves, written out recipe by recipe for the indicator solutions, buffer solutions, test solutions and auxiliary products the reagent test methods call for. The general provisions tie the work to GB/T 601 and GB/T 602 for standard titration solutions and standard solutions, so that the three documents together account for every solution a reagent laboratory prepares in-house. Writing the recipes down is what makes results comparable: an indicator made up at a different strength, or in a different solvent, moves the colour change an analyst reads as the endpoint, and two laboratories testing the same batch then disagree for reasons that have nothing to do with the batch. The preparation clause also carries a warning that some of the reagents involved are toxic or corrosive and that some steps can become dangerous, leaving the operator responsible for the safety and health measures. Written for reagent manufacturers, testing and calibration laboratories, and the bodies that verify reagent quality.

This document specifies the preparation methods for reagent solutions for use in test methods

of chemical reagent.

This document is applicable to the preparation of preparations and products required for

chemical reagent analysis. It can also be used in other fields.

2 Normative References

The contents of the following documents constitute indispensable clauses of this document

through the normative references in the text. In terms of references with a specified date, only

versions with a specified date are applicable to this document. In terms of references without a

specified date, the latest version (including all the modifications) is applicable to this document.

GB/T 601 Chemical Reagent - Preparations of Standard Volumetric Solutions

GB/T 602 Chemical Reagent - Preparations of Standard Solutions for Impurity

GB/T 6682 Water for Analytical Laboratory Use - Specification and Test Methods

GB/T 9733 Chemical Reagent - General Method for the Determination of Carbonyl Compounds

3 Terms and Definitions

This document does not have terms or definitions that need to be defined.

4 General Provisions

4.1 Unless otherwise specified in this document, the reagents used shall be of analytically pure

(including analytically pure) or above. The standard titration solutions and standard solutions

used shall be prepared in accordance with the stipulations of GB/T 601 and GB/T 602.The test

water shall comply with the specifications of Grade-3 water in GB/T 6682, and the reagents

shall be weighed accurately to 0.01 g or measured accurately to 0.1 mL.

4.2 Unless otherwise specified in this document, all solvents not specified are water.

4.3 The test solution (A + B) involved in this document refers to solute A and solvent B that are

mutually miscible.

4.4 Except for “ethanol (95%)”, all solutions expressed in percentage (%) in this document are

mass fractions.

4.5 The material of containers used to store preparations and products shall not physically or

chemically interact with the preparations and products.

4.7 When the preparations and products manifest turbidity, precipitation, moisture absorption

or changes in color, they shall be prepared again.

5 Preparation Methods

WARNING. some reagents used in the preparation methods are toxic or corrosive. Some

test processes may lead to dangerous situations. The operator is responsible for taking

appropriate safety and health measures.

5.1 Preparations

5.1.1 General preparations

5.1.1.2 Saturated hydrogen sulfide water

In the fume hood, as shown in Figure 1, connect the device. Add hydrochloric acid solution

(20%) to A, and add ferrous sulfide to B. The hydrochloric acid solution (20%) is dripped from

A into B, and the generated hydrogen sulfide gas is passed into carbon dioxide-free water, until

the D solution is saturated (the mass no longer increases).

5.1.1.3 Saturated bromine water

In the fume hood, measure-take 10 mL of bromine, add it to a brown bottle filled with 75 mL

of water, shake it well, and place it for stratification. The supernatant liquid is saturated bromine

water.

5.1.2 Test solution

5.1.2.1 Ammonia solution

5.1.2.1.1 Ammonia solution (2.5%)

Measure-take 103 mL of ammonia water and dilute to 1,000 mL.

5.1.2.1.2 Ammonia solution (10%)

Measure-take 400 mL of ammonia water and dilute to 1,000 mL.

5.1.2.2 Phenyl anthranilic acid-ethanol solution (1 g/L)

Weigh-take 0.1 g of phenyl anthranilic acid, dissolve it in ethanol (95%), and use ethanol (95%)

to dilute to 100 mL.

5.1.2.3 Phenylfluorone solution (0.1 g/L)

Weigh-take 0.01 g (accurate to 0.0001 g) of phenylfluorone (benzofluorenone), add an

appropriate amount of ethanol (95%), warm to dissolve it; add 1 mL of hydrochloric acid

solution (20%), and use ethanol (95%) to dilute to 100 mL.

5.1.2.4 Benzoylphenylhydroxylamine solution (20 g/L)

Weigh-take 2 g of benzoyl phenyl hydroxylamine (tantalum reagent), dissolve it in ethanol

(95%), and use ethanol (95%) to dilute to 100 mL. The usage period is 6 months.

5.1.2.5 Benzopenttrione color developer

5.1.2.6 Ammonium pyrrolidine dithiocarbamate (APDC) solution (10 g/L)

Weigh-take 1 g of ammonium pyrrolidine dithiocarbamate (APDC), dissolve it in water, dilute

to 100 mL, if necessary, filter it.

5.1.2.40 Potassium sulfate ethanol solution (0.2 g/L)

Weigh-take 0.2 g of potassium sulfate, dissolve it in 700 mL of water and use ethanol (95%) to

dilute to 1,000 mL.

5.1.2.41 Manganese sulfate solution

Weigh-take 67 g of manganese sulfate monohydrate (manganese sulfate), dissolve it in 500 mL

of water, add 138 mL of phosphoric acid and 130 mL of sulfuric acid, and dilute to 1,000 mL.

5.1.2.42 Sodium sulfate solution (400 g/L)

Weigh-take 40 g of anhydrous sodium sulfate, dissolve it in water and dilute to 100 mL.

5.1.2.43 Sulfuric acid solution

5.1.3 Buffer solutions

5.1.3.1 Ammonia-ammonium chloride buffer solution

5.1.3.1.1 Ammonia-ammonium chloride buffer solution A (pH  10)

Weigh-take 54 g of ammonium chloride, dissolve it in water, add 350 mL of ammonia water,

and dilute to 1,000 mL.

5.1.3.3 Acetic acid-ammonium acetate buffer solution

5.1.3.3.1 Acetic acid-ammonium acetate buffer solution (pH 4 ~ 5)

Weigh-take 38.5 g of ammonium acetate, dissolve it in water, add 28.6 mL of acetic acid (glacial

acetic acid), and dilute to 1,000 mL.

5.1.3.3.2 Acetic acid-ammonium acetate buffer solution (pH  6.5)

Weigh-take 59.8 g of ammonium acetate, dissolve it in water, add 1.4 mL of acetic acid (glacial

acetic acid), and dilute to 200 mL.

5.1.3.4 Acetic acid-sodium acetate buffer solution

5.1.4 Indicators and indicator solutions

5.1.4.1 Thymol blue indicator solution (1 g/L)

Weigh-take 0.1 g of thymol blue, dissolve in ethanol (95%), and use ethanol (95%) to dilute to

100 mL.

5.1.4.2 Thyme phenolphthalein indicator solution (1 g/L)

Weigh-take 0.1 g of thymolphthalein, dissolve it in ethanol (95%), and use ethanol (95%) to

dilute to 100 mL.

5.1.4.3 Saturated 2,4-dinitrophenol indicator solution

Saturated aqueous solution of 2,4-dinitrophenol.

5.1.4.4 N-benzene-anthranilic acid indicator solution (2 g/L)

Weigh-take 0.2 g of N-benzene-anthranilic acid, dissolve it in a small amount of water, add 0.2

g of anhydrous sodium carbonate, warm and dissolve it, and dilute to 100 mL. Prepare it just

before use.

5.1.4.5 Phenol red indicator solution (0.2 g/L)

Weigh-take 0.05 g (accurate to 0.0001 g) of phenol red, add 2.85 mL of sodium hydroxide (2

g/L) and 5 mL of ethanol (95%), warm to dissolve it. Then, add 50 mL of ethanol (95%) and

use water to dilute to 250 mL.

5.1.4.6 1-(2-pyridylazo)-2-naphthol (PAN) indicator solution (1 g/L)

Weigh-take 0.1 g of 1-(2-pyridylazo)-2-naphthol (PAN), dissolve it in ethanol (95%) and use

ethanol (95%) to dilute to 100 mL.

5.1.4.10 Sodium diphenylamine sulfonate indicator solution (5 g/L)

Weigh-take 0.5 g of sodium diphenylamine sulfonate, dissolve it in water and dilute to 100 mL.

5.1.4.11 Phenylazoformic acid 2-phenylhydrazide indicator solution

5.1.4.11.1 Phenylazoformic acid 2-phenylhydrazide indicator solution (0.25 g/L)

Weigh-take 0.025 g (accurate to 0.0001 g) of phenylazoformic acid 2-phenylhydrazide, dissolve

it in ethanol (95%) and use ethanol (95%) to dilute to 100 mL.

5.1.4.11.2 Phenylazoformic acid 2-phenylhydrazide indicator solution (5 g/L)

Weigh-take 0.5 g of phenylazoformic acid 2-phenylhydrazide, dissolve it in ethanol (95%) and

use ethanol (95%) to dilute to 100 mL.

5.1.4.12 Xylenol orange indicator solution (2 g/L)

Weigh-take 0.2 g of xylenol orange, dissolve it in water and dilute to 100 mL. The usage period

is 10 days.

5.1.4.13 Dimethyl yellow-methylene blue mixed indicator solution

Weigh-take 1 g of dimethyl yellow and 0.1 g of methylene blue and dissolve it in 125 mL of

methanol.

5.1.4.14 1,10-phenanthroline-ferrous iron indicator solution

Weigh-take 0.7 g of ferrous sulfate heptahydrate, dissolve it in 70 mL of water, add 2 drops of

sulfuric acid, and add 1.5 g of 1,10-phenanthroline (C12H8N2  H2O) [or 1.76 g of 1,10-

phenanthroline hydrochloride (C12H8N2  HCl  H2O)]. After dissolving, dilute it to 100 mL.

Prepare it right before use.

5.1.4.15 Phenolphthalein indicator solution (10 g/L)

Weigh-take 1 g of phenolphthalein, dissolve it in ethanol (95%) and use ethanol (95%) to dilute

to 100 mL.

5.1.4.19 Chrome blue black R indicator

Weigh-take 10 g of anhydrous sodium sulfate that has been dried at 105 C  2 C for 2 hours,

add 0.1 g of chrome blue black R, evenly mix and finely grind it. Store it in a desiccator.

5.1.4.20 Methyl thymol blue indicator

Weigh-take 10 g of potassium nitrate that has been dried at 105 C  2 C for 2 hours, add 0.1

g of methyl thymol blue, evenly mix and finely grind it. Store it in a desiccator.

5.1.4.21 Methyl orange indicator solution (1 g/L)

Weigh-take 0.1 g of methyl orange, dissolve it in water at 70 C, cool and dilute to 100 mL.

5.1.4.22 Methyl red-methylene blue mixed indicator solution

Solution I. weigh-take 0.1 g of methylene blue, dissolve it in ethanol (95%) and use ethanol

(95%) to dilute to 100 mL.

Solution II. weigh-take 0.1 g of methyl red, dissolve it in ethanol (95%) and use ethanol (95%)

to dilute to 100 mL. Take 50 mL of Solution I and 100 mL of Solution II, and evenly mix it.

5.1.4.23 Methyl red indicator solution (1 g/L)

Weigh-take 0.1 g of methyl red, dissolve it in ethanol (95%) and use ethanol (95%) to dilute to

100 mL.

5.1.4.24 Methyl violet indicator solution (0.5 g/L)

Weigh-take 0.05 g (accurate to 0.0001 g) of methyl violet, dissolve it in water, and dilute to 100

mL.

5.1.4.25 Crystal violet indicator solution (5 g/L)

Weigh-take 0.5 g of crystal violet, dissolve it in acetic acid (glacial acetic acid), and use acetic

acid (glacial acetic acid) to dilute to 100 mL.

5.1.4.28 o-toluidine indicator solution (1 g/L)

Weigh-take 0.1 g of o-toluidine, add 10 mL of hydrochloric acid and a small amount of water

to dissolve it, and dilute to 100 mL.

5.1.4.29 Iron (III) ammonium sulfate indicator solution (80 g/L)

Weigh-take 8 g of ammonium iron (III) sulfate dodecahydrate, dissolve it in 50 mL of water

containing a few drops of sulfuric acid, and dilute to 100 mL.

5.1.4.30 alpha-naphthol phenylmethanol-acetic acid indicator solution (2 g/L)

Weigh-take 0.2 g of alpha-naphthol phenylmethanol, dissolve it in acetic acid (glacial acetic acid)

and use acetic acid (glacial acetic acid) to dilute it to 100 mL.

5.1.4.31 Alizarin red S indicator solution (1 g/L)

Weigh-take 0.1 g of alizarin red S, dissolve it in water and dilute to 100 mL.

5.1.4.32 Eosin sodium salt indicator solution (5 g/L)

Weigh-take 0.5 g of eosin sodium salt, dissolve it in water, and dilute to 100 mL.

5.1.4.33 Acid chromium blue K-naphthol green B mixed indicator solution (KB indicator

solution)

Weigh-take 0.3 g of acid chromium blue K and 0.1 g of naphthol green B, dissolve it in water,

and dilute to 100 mL.

5.1.4.34 Bromothymol blue indicator solution (1 g/L)

Weigh-take 0.1 g of bromothymol blue, dissolve it in 50 mL of ethanol (95%), and dilute to 100

mL.

5.1.4.35 Bromophenol blue indicator solution (0.4 g/L)

Weigh-take 0.04 g (accurate to 0.0001 g) of bromophenol blue, dissolve it in ethanol (95%),

and use ethanol (95%) to dilute to 100 mL.

5.1.4.36 Bromocresol green-methyl red indicator solution

Solution I. weigh-take 0.1 g of bromocresol green, dissolve it in ethanol (95%) and use ethanol

(95%) to dilute to 100 mL.

Solution II. weigh-take 0.2 g of methyl red, dissolve it in ethanol (95%) and use ethanol (95%)

to dilute to 100 mL.

5.2 Products

5.2.1 Starch-potassium iodide test paper

Add 0.2 g of potassium iodide to 100 mL of newly prepared starch indicator solution (10 g/L),

soak the ashless filter paper in the solution, take it out, and dry it in the dark. Place it in a brown

bottle.

5.2.2 Mercury bromide test paper

Weigh-take 1.25 g of mercury bromide and dissolve it in 25 mL of ethanol (95%). Soak the

ashless filer paper in the solution for 1 hour, take it out, and dry it in a dark place. Place it in a

brown bottle.

5.2.3 Lead acetate cotton

Take absorbent cotton and soak it with lead acetate solution (50 g/L). Remove the excess

solution and dry it in a dark place. Place it in a brown bottle.

5.2.4 Lead acetate test paper

Take an appropriate amount of ashless filter paper, soak it with lead acetate solution (50 g/L),

take it out and dry in a dark place. Place it in a brown bottle.

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