Some standard content:
HG/T 2759—1996
This standard gives a grade of analytical purity, which is equivalent to R92 "Soluble Starch" in ISO6353-3:1987 "Chemical Analysis Reagents Part 3: Specifications Batch 2". The differences are as follows: 1 Standard Writing
According to my country's national conditions, this standard adds three chapters: properties, inspection rules, packaging and marking. 2 Specifications
In order to make clear provisions for the characteristics of the test solution, this standard lists the preparation of the test solution in the international standard as a water solubility test. Other items and indicators are the same as those of the international standard. 3 Tests
The water solubility test, iodine sensitivity, drying loss, and the determination methods of Fehling's reagent in this standard are the same as those of the international standard. Other items all refer to the corresponding standards in a set of general test methods for chemical reagents that have been formulated in my country. This set of standards is basically formulated using ISO6353-1:1982 "Chemical Analysis Reagents Part 1: General Test Methods". This standard is proposed by the Technical Supervision Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Beijing Chemical Reagent General Administration. This standard is drafted by Beijing Beihua Fine Chemicals Co., Ltd. The main drafter of this standard is Hao Yulin.
This standard was first formulated in 1995.
Chemical Industry Standard of the People's Republic of China
Chemical ReagentswwW.bzxz.Net
Indicative Formula: (C.HtOs)n
1 Scope
Soluble Starch
HG/T 2759— 1996
This standard specifies the technical requirements, test methods, inspection rules, packaging and marking of soluble starch in chemical reagents. Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T 601—1988
GB/T 6031988
GB/T 619—1988
GB/T 6682—1992
GB/T 9724-1988
GB/T 9741—1988
GB 15346---1994
Chemical reagents Preparation of standard solutions for titration analysis (volume analysis) Chemical reagents
Preparation of preparations and products used in test methods Sampling and acceptance rules for chemical reagents
Specifications and test methods for water used in analytical laboratories (eqvISO3696:1987) General rules for determination of pH value of chemical reagents (eqvISO6353-1:1982) General method for determination of ignition residue of chemical reagents (eqvISO6353-1:1982) Packaging and marking of chemical reagents
HG/T3-1168--1978
Preparation and determination method of clarity standard of chemical reagents 3 Properties
This reagent is a white powder. Odorless. Soluble in boiling water, insoluble in cold water, alcohol and ether. Its hot water solution (10g/L) is a transparent, fluorescent liquid.
4 Specifications
Water solubility test
pH (20 g/L, 25C)
Sensitivity to iodine
Loss on drying, %
Residue on ignition, %
Reduced Fehling's reagent substance (calculated as maltose), %5 Test
Unless otherwise specified in this chapter, the standard titration solutions, preparations and products used shall be prepared in accordance with the provisions of GB/T601 and GB/T603. The water used in the experiment shall comply with the specifications of Grade 3 water in GB/T6682, and the samples shall be weighed to an accuracy of 0.01g. Approved by the Ministry of Chemical Industry of the People's Republic of China on April 15, 1996, and implemented on January 1, 1997
5.1 Water solubility test
HG/T 2759—1996
Weigh 2 grams of sample, add 5 mL of water to make a paste, add 95 mL of hot water, and boil for 2 minutes. The turbidity of the hot solution shall not be greater than that of emulsion B specified in HG/T3-1168. After cooling, it forms an emulsion or turbid liquid, but it shall not become a gel. This solution is retained for the determination of pH and sensitivity to iodine.
Take the water solubility test solution (5.1) and measure it according to the provisions of GB/T9724. 5.3 Sensitivity to iodine
Take 2.5mL of water-soluble test solution (5.1), add 97.5mL of water and 0.5mL of iodine standard titration solution [c(1/2Iz)==0.01mol/L), shake well, the solution should be pure blue. After adding 0.5mL of sodium thiosulfate standard titration solution Lc(NazS,0)=0.01mol/L), the blue color of the solution should disappear.
5.4 Drying loss
Weigh 1g of sample (accurate to 0.0001g), place it in a weighing bottle that has been dried to constant weight at (150±2)℃, and dry it to constant weight in an electric oven at (105±2)℃.
The drying loss expressed as a mass percentage is calculated according to formula (1): ml -m2 × 100
X(%) =
Wherein: X is the drying loss expressed as a mass percentage, %; mt-——the mass of the sample before drying, g;
m2-the mass of the sample after drying to constant weight, g. 5.5 Ignition residue
Weigh 1g of sample and measure it according to the provisions of 4.1 of GB/T9741. The result is calculated according to the provisions of Chapter 5 of GB/T9741. 5.6 Reduction of Fehling's reagent
. (1)
Weigh 10g of sample, add 100mL of water, shake for 15min, let it stand for 12h, and filter it with a No. 4 glass filter. Take 50mL of filtrate, add 50mL of Fehling's solution, boil for 2min, filter out cuprous oxide with a No. 4 glass filter crucible that has been dried to constant weight at (105±2)℃, wash the cuprous oxide with water until the washing liquid is neutral, then wash with ethanol and ether respectively, and dry in an electric oven at (105±2)℃ to constant weight. The mass of cuprous oxide shall not exceed 50mg.
Inspection Rules
Sampling and acceptance shall be carried out in accordance with the provisions of GB/T619. Packaging and marking
Packaging, storage and transportation shall be carried out in accordance with the provisions of GB15346, and marking shall be given, including: Packaging unit: Class 4;
Inner packaging form: NB-4, NBY-4, NB-5, NBY-5, NB-7, NB-8, NB-10, NB-11, NB-13, NB-15; Isolation material: GC-2, GC-3;
Outer packaging form: WB-1, WB-2, WB-3. 1194
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