SH/T 0227-1992 Determination of boron content in additives

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 0227-92 (confirmed in 2004)
• Chinese title: Determination of boron content in additives
• English title: not provided in the available source
• Replacement relationship: replaces ZB E60 006-89
• Approval: approved by China Petrochemical Corporation 1992-05-20; implementation date in the source is "1992-05-20 MA" (requires confirmation against the source standard (source-text extraction))

2. Scope of application and non-applicability

• Applicable: additives with boron content from 0.1% to 10% (m/m).
• Not applicable: additives with zinc, phosphorus, or aluminum content at or above 0.2% (m/m).

3. Method principle

The boron-containing additive is fused with alkali to convert the boron in it into tetraborate, dissolved by adding water, adjusted with hydrochloric acid until methyl red turns red, whereupon the tetraborate becomes boric acid, then complexed with mannitol, and titrated with sodium hydroxide standard titration solution.

4. Reagents and materials (purity / preparation)

• 4.1 Sodium hydroxide: analytical reagent.
• 4.2 Potassium hydrogen phthalate: primary standard reagent.
• 4.3 Mannitol: analytical reagent.
• 4.4 Hydrochloric acid: analytical reagent, prepared by volume ratio into a solution of 1:1 concentration and 0.4% (m/m) concentration.
• 4.5 Potassium hydroxide: analytical reagent.
• 4.6 Methyl red indicator: prepared as 1 g/L ethanol indicator solution (the indicator concentration unit is unclear in the source transcription and remains unverified).
• 4.7 Phenolphthalein indicator: prepared as 10 g/L ethanol indicator solution.
• 4.8 Freshly distilled water.
• Material: nitrogen, purity 99.9% (see 3.2).

5. Apparatus and equipment

• 3.1.1 Burette: a micro-burette of 10 mL and a basic burette of 25, 50 mL.
• 3.1.2 Nickel crucible: 30 mL.
• 3.1.3 Analytical balance: sensitivity 0.1 mg.
• 3.1.4 High-temperature furnace.
• 3.1.5 Conical flask: 250 mL, mouth diameter 30 mm.

6. Recommended operating conditions

• Sodium hydroxide standard titration solution concentration: c(NaOH) = 0.05 mol/L (see 5.1).
• Fusion temperature: first in a 200℃±25℃ high-temperature furnace, then raised to 550℃±25℃, held constant for 0.5 h (see 6.1).
• Nitrogen flow rate: 2 L/min (the source text "2Umin" requires confirmation against the source standard (source-text extraction)) (see 6.3).
• Nitrogen purge time: 10 min (see 6.4).

7. Sampling and test specimen preparation

• Weigh 0.1000 to 0.3000 g of test specimen into a nickel crucible, add 2 g potassium hydroxide to cover the specimen (see 6.1).

8. Analytical procedure

• 6.1 Weigh 0.1000 to 0.3000 g of test specimen into a nickel crucible, add 2 g potassium hydroxide to cover the specimen, place in a high-temperature furnace at 200℃±25℃, then raise to 550℃±25℃, and hold constant for 0.5 h.
• 6.2 Stop heating the high-temperature furnace, remove and cool, then add distilled water to wash all the melt into a conical flask, add 2 drops of methyl red-ethanol indicator solution, adjust to red with 1:1 hydrochloric acid solution (1:1 hydrochloric acid solution must not be in excessive excess), and rinse the mouth of the conical flask with distilled water.
• 6.3 Pass nitrogen into the solution in the conical flask at a rate of 2 L/min; if the methyl red fades, continue adjusting with 0.4% (m/m) hydrochloric acid solution until the solution always remains faintly red.
• 6.4 After passing nitrogen for 10 min, accurately adjust the solution in the conical flask to bright yellow with sodium hydroxide standard titration solution, add 3 g mannitol and 3 drops of phenolphthalein-ethanol indicator solution.
• 6.5 Gently shake the flask to allow complete complexation; at this time the solution is red, then titrate with sodium hydroxide standard titration solution; when the solution changes from yellow to faintly red, this is the endpoint. Record the volume (mL) of sodium hydroxide standard titration solution consumed.
• 6.6 Using the same procedure, carry out a blank test without adding test specimen, and record the volume (mL) of sodium hydroxide standard titration solution consumed.
• Note: Throughout the entire test procedure, the nitrogen must not be interrupted, and distilled water must not be used to rinse the conical flask.

9. Qualitative and quantitative determination and calculation formulas

• The actual concentration of sodium hydroxide standard titration solution c(NaOH), mol/L, is calculated according to formula (1): c(NaOH) = m₁ / [(V₁ − V₀) × 0.20423] Where: m₁—mass of potassium hydrogen phthalate, g; V₁—volume of sodium hydroxide solution consumed during titration, mL; V₀—volume of sodium hydroxide solution consumed in the blank test, mL; 0.20423— and 1.000 mL mass of potassium hydrogen phthalate, expressed in grams, equivalent to sodium hydroxide standard titration solution [c(NaOH)=1.000 mol/L].
• Boron content in the test specimen X, % (m/m), is calculated according to formula (2): X = (V − V₂) × c(NaOH) × 0.01081 / m Where: V— volume of sodium hydroxide standard titration solution consumed in titrating the test specimen, mL; V₂—volume of sodium hydroxide standard titration solution consumed in titrating the blank, mL; c(NaOH)— actual concentration of sodium hydroxide standard titration solution, mol/L; 0.01081— and 1.000 mL mass of boron, expressed in grams, equivalent to sodium hydroxide standard titration solution [c(NaOH)=1.000 mol/L]; m— mass of the test specimen, g (the source text "Ko" requires confirmation against the source standard (source-text extraction)).

10. Precision

Judge the reliability of the determination results according to the following provisions (95% confidence level):

• 8.1 Repeatability: the difference between two results obtained by the same operator in repeated determinations shall not exceed 2% of the arithmetic mean.
• 8.2 Reproducibility: the difference between two results submitted by different laboratories shall not exceed 3.2% of the arithmetic mean.

11. Report

Take the arithmetic mean of two results from repeated determinations as the boron content of the test specimen.

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-reference Q&A