SH/T 0223-1992 Determination of barium content in additives (complexometric titration)

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

1. Method number / full title / English name / replacement relationship

• Standard number: SH/T 0223-92 (confirmed in 2004)
• Chinese full title: Determination of barium content in additives (complexometric titration)
• English name: not provided in the available source
• Replacement relationship: replaces ZB E60 001-86
• Approval/implementation: approved by China Petrochemical Corporation in 1992-05-20, implemented in 1992-05-20

2. Scope of application and non-applicability

• This standard specifies a method for determining barium content in additives by complexometric titration.
• Applicable to sulfurized additives containing the single metal element barium.
• The nonmetal elements sulfur, phosphorus, nitrogen, chlorine, and silicon do not interfere with the determination.
• The iron content in the sample should be less than 300ppm.
• The determination range is 1%～20%(m/m).
• Not applicable: not provided in the available source.

3. Method principle

Place a certain amount of sample in a 30mL porcelain crucible, place the porcelain crucible on an electric furnace and first burn off its organic matter, ignite the residue in a 800℃ high-temperature furnace for 10min, after the crucible cools, dissolve the residue in the crucible with 7%(m/m) hydrochloric acid solution and transfer it to a 250mL conical flask, use methyl orange as indicator, adjust the solution to yellow with ammonia water, then add excess ammonia water and EDTA standard titration solution, use eriochrome black T as indicator, back-titrate the excess EDTA standard titration solution with a magnesium chloride standard titration solution of known concentration until the solution becomes light purple, and calculate the barium content from the volume of EDTA standard titration solution and the volume of magnesium chloride standard titration solution consumed during back-titration.

4. Reagents and materials (purity / preparation)

Unless otherwise specified, the reagents used in this standard are of analytical reagent grade, and the water is distilled water.

• 4.1 Disodium ethylenediaminetetraacetate.
• 4.2 Ammonia water: ammonia content 25%～28%(m/m), prepared as a 4%(m/m) solution.
• 4.3 Ammonium chloride.
• 4.4 Hydrochloric acid: prepared as 19%(m/m) and 7%(m/m) solutions.
• 4.5 Methyl orange: prepared as a 1g/L indicator solution (the source text at source-text extraction is “I[unreadable characters]L”, requires confirmation against the source standard (source-text extraction)).
• 4.6 Eriochrome black T indicator: 1g eriochrome black T and 100g sodium chloride, mixed and ground uniformly, then stored in a wide-mouth bottle with a ground stopper (shelf life one year).
• 4.7 Magnesium chloride.
• 4.8 Sodium chloride.
• 4.9 Zinc granules.
• 4.10 Zinc oxide: primary standard reagent.
• 4.11 Triethanolamine: prepared as a 30%(V/V) solution.
• 4.12 Anhydrous ethanol.

5. Instruments and equipment

• 3.1 Tall-form porcelain crucible: 30mL.
• 3.2 Burette: 25mL.
• 3.3 Conical flask: 250mL.
• 3.4 High-temperature furnace: 0～1000℃.
• 3.5 Balance: sensitivity 0.1mg.
• 3.6 Graduated cylinder: 10mL.
• 3.7 Volumetric flask: 1000mL.
• 3.8 Pipette: 20, 25mL.
• 3.9 Short glass rod with rubber sleeve.

6. Recommended operating conditions

• Ignition temperature: 800℃ high-temperature furnace.
• Ignition time: 10min.
• Titration temperature/heating: heat the conical flask on an electric furnace, bring to a slight boil for 30s.
• Buffer solution pH: 10.
• Other: not provided in the available source.

7. Sampling and sample preparation

• 6.1 In a 30mL tall-form porcelain crucible, weigh a certain amount of additive according to the table below.

Sample amount table:

• 6.2 Roll half a sheet of sufficient filter paper into a cone with an ignition wick, stand it in the porcelain crucible containing the sample, and cover the surface of most of the sample.

8. Analytical procedure

• 6.3 First place the porcelain crucible on an electric furnace and heat it; after a large amount of oil fume emerges, ignite the ignition wick of the conical filter paper to burn off its combustible matter, then ignite the porcelain crucible in a 800℃ high-temperature furnace for 10min. After taking it out and cooling it, first moisten it with a small amount of distilled water, then dissolve its ash with 2mL 19%(m/m) hydrochloric acid; during dissolution, place the porcelain crucible on an electric furnace and heat gently for 2～3min. Then transfer the solution to a 250mL conical flask, add 1 drops of methyl orange indicator solution, adjust the solution to yellow with ammonia water, then add about 1mL of 30% triethanolamine (may be omitted when the sample contains no iron).
• 6.4 Use a pipette to accurately add 25mL of EDTA standard titration solution of known concentration and about 10mL ammonia water. Heat the conical flask on an electric furnace and bring to a slight boil for 30s. After the solution cools, add 10mL of ammonia buffer solution with pH of 10, and about 0.1g of eriochrome black T indicator.
• 6.5 Back-titrate with a magnesium chloride standard titration solution of known concentration until the solution becomes light purple.

9. Qualitative and quantitative determination and calculation formula

The percentage content of barium in the sample X[%(m/m)] is calculated according to formula (5):

X = [c(EDTA)·V5 − c(MgCl2)·V6] × 0.1374 × 100 / m

Where:

• c(EDTA)——EDTA actual concentration of the standard titration solution, mol/L;
• c(MgCl2)—— actual concentration of the magnesium chloride standard titration solution, mol/L;
• V5—— volume of EDTA standard titration solution of known concentration added, mL;
• V6—— volume of magnesium chloride standard titration solution consumed in back-titrating the excess EDTA standard titration solution, mL;
• m—— sample mass, g;
• 0.1374—— mass of barium, expressed in grams, equivalent to 1.00mL EDTA standard titration solution [c(EDTA)=1.000mol/L].

10. Precision

Use the following provisions to judge the reliability of test results (95% confidence level).

• 8.1 Repeatability: the difference between two determinations by the same operator shall not exceed 4% of the arithmetic mean.
• 8.2 Reproducibility: the difference between determination results from two different laboratories shall not exceed 6.5% of the arithmetic mean.

11. Report

Take the arithmetic mean of two results from repeated determinations as the determination result, to three significant figures.

12. Referenced documents

not provided in the available source.

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick Q&A reference