SH/T 0343-1992 Determination of chlorine content in catalysts (ion-selective electrode method)

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Card type: Test method

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

• Standard number: SH/T 0343-92 (confirmed in 2004)
• Chinese full name: Determination of chlorine content in catalysts (ion-selective electrode method)
• English name: not provided in the available source
• Replacement relationship: replaces SY 2774-78S
• Approval/implementation: approved by China Petrochemical Corporation 1992-05-20, implemented on 1992-05-20

2. Scope of application and non-applicability

• Scope of application: This standard applies to the determination of chlorine content in fresh reforming and catalytic cracking catalysts.
• Not applicable: not provided in the available source.

3. Method principle

After the chlorine in the sample is extracted with sodium hydroxide solution, the chloride ions in the sample solution are determined with a chloride ion-selective electrode, and quantitative determination is carried out by the standard addition method.

4. Reagents and materials (purity / preparation)

• 4.1 Potassium chloride: analytical reagent, prepared as a saturated solution.
• 4.2 Potassium nitrate: analytical reagent, prepared as a solution with a concentration of 10 g/L.
• 4.3 Nitric acid: analytical reagent, prepared as a 1:3 (by volume ratio) solution.
• 4.4 Sodium hydroxide: analytical reagent, prepared as a solution with a concentration of 20 g/L.
• 4.5 Sodium chloride: spectroscopically pure.
• 4.6 Water: deionized water, conductivity not greater than 5 μS/cm (the source text reads “51 ,S/cm”, requires confirmation against the source standard (source-text extraction)).
• 3.2 Materials: pH test paper pH 1～14.

5. Instruments and equipment

• 3.1.1 Ion meter.
• 3.1.2 Chloride ion-selective electrode.
• 3.1.3 Reference electrode: 217 type double-junction saturated calomel electrode (or other calomel electrode of the same type).
• 3.1.4 Volumetric flasks: 50, 1000 mL.
• 3.1.5 Beakers: 100 mL.
• 3.1.6 Weighing bottles.
• 3.1.7 Microsyringes: 0.1, 0.5 mL.
• 3.1.8 High-temperature furnace.

6. Recommended operating conditions

• 5.3 Connect the ion meter to the power supply; the instrument stabilization time shall be as required by the instruction manual.
• 5.4 Fill the inner sleeve of the reference electrode with saturated potassium chloride solution and the outer sleeve with potassium nitrate solution, preventing bubbles from forming.
• 5.5 Immerse the indicator electrode in 0.001 mol/L sodium chloride reference solution for activation for 1 h. If the electrode has not been used for a long time, it must be activated for 2 h.
• 6.2 During measurement, stir for 3 min, then let stand for 2 min, and read the potential reading.
• 6.4.1 Determination of ignition basis: raise the temperature to 850 ℃, and hold at constant temperature for 1 h.

7. Sampling and sample preparation

• 6.1 Sample treatment: weigh a sample ground to about 150 mesh, 0.1～0.2 g (accurate to 0.0002 g), into a 100 mL beaker, add 10 mL sodium hydroxide solution (clause 4.4), 20 mL water, and boil for 20 min. After cooling, adjust the pH value to 6～8 with nitric acid solution. Transfer the solution to a 50 mL volumetric flask and dilute to the mark with water. After mixing well, pour all the solution into a 100 mL beaker and set aside for determination.
• 6.4.1 Determination of ignition basis: while weighing the sample, weigh 0.5～1 g (accurate to 0.0002 g) of sample into a constant-weight covered porcelain crucible, place it in a high-temperature furnace, raise the temperature to 850 ℃, hold at constant temperature for 1 h, then remove, place in a desiccator to cool to room temperature (about 0.5 h), and weigh.

8. Analytical procedure

• 5.1 Preparation of c(NaCl)=0.1 mol/L (0.1N) sodium chloride reference solution: accurately weigh 5.8443 g of sodium chloride that has been ignited at 500～600 ℃ to constant weight, dissolve in water, transfer to a 1 L volumetric flask, dilute to the mark, and mix well. It may be stored for three months; if it becomes turbid or a precipitate forms during this period, it shall be freshly prepared.
• 5.2 Preparation of c(NaCl)=0.001 mol/L (0.001N) sodium chloride reference solution: accurately measure 10 mL c(NaCl)=0.1 mol/L (0.1N) sodium chloride reference solution into a 1 L volumetric flask, dilute to the mark with water, and mix well.
• 6.2 Determination of sample: connect the chloride ion-selective electrode, the 217 type double-junction saturated calomel electrode, and the ion meter. Wash the electrode with water until the blank potential in water meets the requirements of the instrument instruction manual. Blot the water droplets on the electrode surface with filter paper. Insert the electrode into the test solution, stir for 3 min, then let stand for 2 min, and read the potential reading E₁. Then accurately add a certain amount of sodium chloride reference solution to this solution with a microsyringe [when the chlorine content in the sample exceeds 1%(m/m), add 0.5 mL 0.1 mol/L sodium chloride reference solution; when the chlorine content is less than 1%(m/m), add 0.1 mL 0.1 mol/L sodium chloride reference solution], stir for 3 min, then let stand for 2 min, and read the potential reading E₂. Remove the test solution and wash the electrode.
• 6.3 Blank test: add 10 mL sodium hydroxide solution (clause 4.4) to a 50 mL volumetric flask, and accurately add 0.1 mL sodium chloride reference solution (clause 5.1), then adjust to a pH value of 6～8 with nitric acid solution, dilute to the mark with water, and mix well. Pour all the blank solution into a 100 mL beaker, insert the electrode, stir for 3 min, let stand for 2 min, and read the potential reading E₁. Then accurately add 0.1 mL sodium chloride reference solution (clause 5.1) to this solution, stir for 3 min, then let stand for 2 min, and read the potential reading E₂.
• 6.4 Determination of ignition basis: operate according to 6.4.1, calculate the ignition basis according to formula (1), and take the arithmetic mean of the results of repeated tests as the ignition basis.

9. Qualitative and quantitative determination and calculation formulas

• 7.1 The chlorine content in the sample X[%(m/m)] is calculated according to formula (2), (3) and formula (4) (the original formulas source-text extraction are noisy; the following is the recognizable content of the source text, requires confirmation against the source standard (source-text extraction)):
  • Formula (1): B = (m₂ − m₀) / (m₁ − m₀) × 100 (the source text is typeset as “B[unreadable sign]m2 - ma / M I”, requires confirmation against the source standard (source-text extraction)) Where: m₀—mass of the crucible after constant weight, g; m₁—mass of the sample before ignition, g; m₂—total mass of the sample and crucible after ignition, g.
  • Formula (2): the source text reads “[unreadable sign] 0.2 x 10[unreadable sign]3 ... n [unreadable sign] ... x lu ... 1 [unreadable characters]C ,1 ... [unreadable character]l ogl -s ~)’ [unreadable character] ... K ... ，IE [unreadable sign]E,) [unreadable character]log( .4-)[unreadable sign]’”, requires confirmation against the source standard (source-text extraction).
  • Formula (3): no complete recognizable content is provided in the available source, requires confirmation against the source standard (source-text extraction).
  • Formula (4): X = c × 35.45 × 50 / (m × 1 × 1 × 100) = c × 177.25 (the source text reads “X=cx35.45x50 / m x Ilxx1 x 100= c x 177.25”, requires confirmation against the source standard (source-text extraction)) Where: K— chloride ion concentration measured in the blank test, mol/L; 0.2 × 10⁻³—change in concentration of the test solution after adding 0.1 mL sodium chloride reference solution, mol/L; A—0.2 × 10⁻³ [when the chlorine content is less than 1%(m/m), change in concentration of the test solution after adding 0.1 mL sodium chloride reference solution, mol/L]; 1 × 10⁻³ [when the chlorine content is greater than or equal to 1%(m/m), change in concentration of the test solution after adding 0.5 mL sodium chloride reference solution, mol/L]; E₁—potential value of the first measurement, mV; E₂—potential value of the second measurement, mV; S— electrode slope; c— chloride ion concentration in the test solution, mol/L; m— mass of the sample, g.
• 7.2 If calculated on an ignition basis, the chlorine content in the sample X₁[%(m/m)] is calculated according to formula (5): X₁ = X / B × 100 (the source text reads “X [unreadable character]1[unreadable characters]x n[unreadable character]”, requires confirmation against the source standard (source-text extraction)) Where: B— ignition basis of the sample, %(m/m); X— chlorine content in formula (4), %(m/m).

10. Precision

• Repeatability: The difference between two results obtained by repeated determination by the same operator shall not exceed 10% of their arithmetic mean.

11. Report

• Take the arithmetic mean of two repeated determination results as the determination result.

12. Reference 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