SH/T 0346-1992 Determination of nickel content in hydrorefining catalysts

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 name / English name / replacement relationship

• Standard number: SH/T 0346-92
• Full name: Determination of nickel content in hydrorefining catalysts
• English name: not provided in the available source
• Replacement relationship: replaces SY 2778-78
• Other: confirmed in 2004; 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 specifies the method for determination of nickel content in hydrorefining catalysts; applicable to hydrorefining catalysts.
• Not applicable: not provided in the available source.

3. Method principle

The sample is dissolved with sulfuric acid. In an alkaline solution and in the presence of an oxidizing agent, divalent nickel ions react with butanedione (requires confirmation against the source standard (source-text extraction), suspected to be dimethylglyoxime) to form a soluble red complex [Ni(C4HrN202)2(H20)21+2 (requires confirmation against the source standard (source-text extraction))], and then colorimetric determination is carried out.

4. Reagents and materials (purity / preparation)

• 4.1 Potassium sodium tartrate: analytical grade, prepare as 200 g/L solution.
• 4.2 Sodium hydroxide: analytical grade, prepare as 50 g/L, 100 g/L solution (original text “50&/L” requires confirmation against the source standard (source-text extraction)).
• 4.3 Iron persulfate: analytical grade, prepare as 30 g/L solution (easily deteriorates, not suitable to prepare in large amounts). (Original text “iron persulfate” requires confirmation against the source standard (source-text extraction), suspected to be ammonium persulfate)
• 4.4 Butanedione alkaline solution: prepare as 10 g/L solution (the diluent is 50 g/L sodium hydroxide solution). (“Butanedione” requires confirmation against the source standard (source-text extraction))
• 4.5 Sulfuric acid: analytical grade, prepare as 1:1 (by volume ratio) solution.
• 4.6 Hydrochloric acid: analytical grade.
• 4.7 Nitric acid: analytical grade.
• 4.8 Nickel oxide: spectrally pure (or nickel wire: purity 99.9%).
• 3.2 Materials: pH test paper pH 1—14 (original text “pHl[unreadable separator]140” requires confirmation against the source standard (source-text extraction)).
• 5.1 Aqua regia: hydrochloric acid and nitric acid mixed in 3:1 (by volume ratio), prepared before use.

5. Instruments and equipment

• a. Spectrophotometer: capable of absorbance measurement in the 460 nm wavelength region (original text “460.” requires confirmation against the source standard (source-text extraction)).
• b. Volumetric flasks: 100, 250, 1000 mL.
• c. Pipettes: 5, 10 mL.
• d. Burette: 10 mL.
• e. Graduated cylinders: 10, 20 mL.
• f. Beakers: 100, 250 mL.
• g. Watch glass.
• h. Funnel: diameter 75 mm.
• i. Wash bottle.

6. Recommended operating conditions

• Cuvette: 3 cm.
• Measurement wavelength: at the 460 nm wavelength of the spectrophotometer (original text “461)[unreadable character] at the wavelength” requires confirmation against the source standard (source-text extraction)).
• Color development standing time: measure after standing for 10 min.
• Working curve: plot absorbance as the ordinate and milligrams of nickel as the abscissa.

7. Sampling and sample preparation

• 6.1 Grind a representative sample to about 150 mesh, place in an oven at 150—155 ℃ and dry for 1 h. After removal, place in a desiccator for 20 min.
• Weigh 0.1—0.15 g (accurate to 0.0002 g) into a 250 mL beaker.
• Note: The sampling amount of the sample solution may be appropriately increased or decreased according to the range of nickel content in the sample.

8. Analytical procedure

• 6.1 Sample dissolution: Weigh the sample into a 250 mL beaker, first rinse the beaker wall with a small amount of water, then add sulfuric acid solution (1:1) 10 mL, place a glass rod, cover with a watch glass, place on an electric furnace and heat, stirring occasionally. When white fumes just begin to appear, remove the beaker. After cooling, rinse the watch glass and beaker wall with hot water until the solution volume in the beaker is about 50 mL, filter the solution into a 250 mL volumetric flask, rinse the filter paper with hot water until the filter paper no longer tests acidic with pH test paper. After the solution cools, dilute to the mark with water and shake well.
• 6.2 Determination: Use a pipette to accurately measure 6.1 aliquot of solution 5 mL into a 100 mL beaker, and operate according to clause 5.3. Measure the absorbance of the solution, and find the milligrams of nickel in the solution from the working curve.
• 5.2 Preparation of nickel standard solution: Accurately weigh spectrally pure nickel oxide 0.1273 g into a 100 mL beaker, add 20 mL aqua regia, slowly heat to dissolve. If residue remains, add a small amount of aqua regia and continue heating until completely dissolved. After cooling, transfer to a 1000 mL volumetric flask, dilute to the mark with water and shake well. Use a pipette to accurately measure this solution 10 mL into a 100 mL volumetric flask, dilute to the mark and shake well. This solution contains nickel 0.01 mg per milliliter. This standard solution can be stored for half a year; if turbidity or precipitate appears, it should be re-prepared.
• 5.3 Preparation of working curve: Use a 10 mL burette to accurately measure nickel standard solution 2.00, 4.00, 6.00, 8.00, 10.00 mL into 100 mL volumetric flasks, add to each 200 g/L potassium sodium tartrate solution 10 mL, 100 g/L sodium hydroxide solution 10 mL, 30 g/L ammonium persulfate (original text “persulfate [garbled cation name]” requires confirmation against the source standard (source-text extraction)) solution 10 mL, 10 g/L butanedione alkaline solution 10 mL, then dilute to the mark with water and shake well. After standing for 10 min, simultaneously carry out a blank test with the same reagents. Use a 3 cm cuvette to measure the absorbance at the 460 nm wavelength on the spectrophotometer. Plot the working curve with absorbance as the ordinate and milligrams of nickel as the abscissa.

9. Qualitative and quantitative determination and calculation formula

The nickel content in the sample X [% (m/m)] is calculated according to the following formula:

X = (S · D) / (m × 1000) × 100

Where:

• S—— milligrams of nickel found from the working curve;
• D—— dilution factor of the sample;
• m—— mass of the sample, g.

(The original formula source-text extraction is severely noisy, the denominator “m X 11[garbled denominator symbols]” requires confirmation against the source standard (source-text extraction); the formula form has been arranged according to context, requires confirmation against the source standard (source-text extraction))

10. Precision

Repeatability: The difference between two results of repeated determinations 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. 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