GB/T 602-2002 Chemical reagent--Preparations of STANDARD solutions for impurity (Text of Document is in English) - Beijing translation compay

1. Aspect(s) Covered
This standard regulates method for preparation of standard solutions for impurity of chemical reagent.
This standard is applicable to prepare solution that contains substances (element, ion or molecular) of accurate quantity in unit volume and to measure impurity in chemical reagent. It can also be referred to by other industries.
2. Normative references
The following documents contain contents which, through reference in this text, composite provisions of this standard. For dated reference, subsequent amendments (excepting corrigenda content) to, or revisions of, any of these publications do not apply. Parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. For undated references, the latest edition of the normative document referred to applies.
GB/T 601-2002 Chemical Reagent - Preparations of Standard Volumetric Solutions
GB/T 603-2002 Chemical Reagent - Preparations of Reagent Solutions for Use in Test Methods
GB/T 685-1993 Chemical Reagent - Formaldehyde Solution (neq ISO 6353-3:1987)
GB/T 6682-1992 Water for Analytical Laboratory Use - Specification and Test Methods (neq ISO 3696:1987)
GB/T 6684-2002 Chemical Reagents - 30% Hydrogen Peroxide
3. General Provisions
3.1 Unless other stated herein, purity of reagent used in this standard shall be higher than analytical purity, standard volumetric solution and preparations shall be made according to GB/T 601-2002 and GB/T 603-2002, and water for test use shall be compliant to class-III water specification of GB/T 6682-1992.
3.2 Measurement of standard solution used for measurement of impurity
PREFIX = ST1 3.2.1 Standard solution used for measurement of impurity shall be taken with graduated pipette. Volume of graduated pipette shall not exceed three times volume of standard solution used for measurement of impurity.
3.2.2 Volume of standard solution used for measurement of impurity taken each time shall be 0.05mL-2.00mL. If volume that is adopted is less than 0.05mL, standard solution used for measurement of impurity shall be diluted in relevant proportion, and volume of diluted solution that is adopted shall not be less than 0.05mL during operation; if volume that is adopted is greater than 2.00mL, quantity of reagent and preparation shall be increased in relevant proportion on basis of preparation method of standard solution used for measurement of impurity, and volume of the solution shall not be greater than 2.00mL during operation.
3.3 Unless otherwise stated, in room temperature (15℃- 25℃), guarantee period of standard solution used for measurement of impurity shall be two months in general; if the standard solution has turbidity and deposit or its color is changed, new standard solution shall be prepared.
3.4 Symbol % used herein to express solution refers to mass fraction, only refers to volume fraction in ethanol (95%).