SH/T 0345-1992 Determination of cobalt content in hydrorefining catalysts

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Card type: Test method

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

• Standard number: SH/T 0345-92
• Chinese title: Determination of cobalt content in hydrorefining catalysts
• English title: not provided in the available source
• Replacement relationship: replaces SY 2777-78
• Other: approved by 1992-05-20, implemented by 1992-05-20; (confirmed in 2004)
• Technical committee: Technical committee of the Research Institute of Petroleum Processing
• Drafting units: No. 3 Refinery of Fushun Petrochemical Company, Research Institute of Petroleum Processing

2. Scope of application and non-applicability

• Scope of application: This standard specifies the method for determination of cobalt 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; under the condition that pH is 6, divalent cobalt in the solution forms a red complex Co[CIA O(SO3Na)2NO13] with nitroso-R salt (requires confirmation against the source standard (source-text extraction); the molecular formula extracted from the original text appears to contain noise), and the determination is carried out by colorimetry.

4. Reagents and materials (purity / preparation)

• 4.1 Sodium acetate: analytical reagent, prepared as a 300 g/L solution.
• 4.2 Nitroso-R salt: prepared as a 2 g/L solution (the original text “2[unreadable character]L” requires confirmation against the source standard (source-text extraction)).
• 4.3 Nitric acid: analytical reagent, prepared as 1:1 and 1:3 (volume ratio) solutions.
• 4.4 Sodium hydroxide: chemical reagent, prepared as a 10 g/L solution.
• 4.5 Sulfuric acid: analytical reagent, prepared as a 1:1 (volume ratio) solution.
• 4.6 Sponge cobalt: spectroscopically pure.
• Materials: pH test paper pH 1—4 (the original text “pHl[unreadable separator]40” requires confirmation against the source standard (source-text extraction)).

5. Instruments and equipment

• 3.1.1 Spectrophotometer: capable of absorbance measurement in the 490 nm wavelength region (the original text “490[unreadable character]” requires confirmation against the source standard (source-text extraction)).
• 3.1.2 pH meter.
• 3.1.3 Volumetric flasks: 100, 250, 1000 mL.
• 3.1.4 Pipettes: 5, 10 mL.
• 3.1.5 Burette: 5 mL.
• 3.1.6 Graduated cylinders: 10, 20 mL.
• 3.1.7 Beakers: 100, 250 mL.
• 3.1.8 Watch glass.
• 3.1.9 Funnel: diameter 75 mm.

6. Recommended operating conditions

• Color development pH: 6 (adjusted with a pH meter); if adjusted with pH test paper, pH is 5.0—5.5.
• Color development standing time: 20 min.
• Cuvette: 1 cm.
• Measurement wavelength: 490 nm.
• Blank: use the same reagents for a blank test.

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.
• Weigh 0.1—0.15 g (to the nearest 0.0002 g) 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 in it, cover with a watch glass, place on an electric furnace and heat, stirring from time to time.
• When white fumes just begin to appear upon heating, remove the beaker. After cooling, rinse the watch glass and beaker wall with hot water until the volume of the solution 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 has cooled, dilute to the mark with water and mix well.
• Note: The amount of sample solution taken may be appropriately increased or decreased according to the range of cobalt content in the sample.

8. Analytical procedure

• 5.1 Preparation of cobalt standard solution: accurately weigh spectroscopically pure sponge cobalt 1.000 g into a 250 mL beaker, add nitric acid solution (1:1) 10 mL, cover with a watch glass, place on a hot plate and heat until completely dissolved. After cooling, transfer to a 1 L volumetric flask, dilute to the mark, and mix well. Use a pipette to accurately measure 10 mL of this solution into a 100 mL volumetric flask, dilute to the mark, and mix well. This solution contains 0.1 mg of cobalt per milliliter. This standard solution can be kept for six months; if turbidity or precipitate appears, it should be freshly prepared.
• 5.2 Preparation of the working curve: use a 5 mL burette to accurately measure cobalt standard solution 0.50, 1.00, 1.50, 2.00, 2.50 mL, place them respectively into 100 mL beakers, add 300 g/L sodium acetate 20 mL, 2 g/L nitroso-R salt 10 mL, then dilute with water to about 80 mL, adjust pH to 6 on a pH meter with nitric acid solution (1:3) and 10 g/L sodium hydroxide solution (if adjusted with pH test paper, then pH is 5.0—5.5). Then transfer to a 100 mL volumetric flask, dilute to the mark with water, and mix well. After standing for 20 min, use the same reagents for a blank test. Use a 1 cm cuvette to measure the absorbance at the 490 nm wavelength of the spectrophotometer. Plot the working curve with absorbance as the ordinate and milligrams of cobalt as the abscissa.
• 6.2 Use a pipette to accurately measure 6.1 of the sample solution 5 mL into a 100 mL beaker, and operate according to clause 5.2. Measure the absorbance of the solution, and find the milligrams of cobalt in the solution from the working curve.

9. Qualitative and quantitative determination and calculation formula

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

x = (S · D) / (m × 1000) × 100

Where:

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

(Note: The original formula source-text extraction was extracted in noisy forms such as “S ·D / [unreadable character]L X It[unreadable characters]1”; the above formula has been organized according to the relationships among physical quantities and units, and “1000” and “×100” in the denominator have been completed according to mg and g, and percentage content conversion; requires confirmation against the source standard (source-text extraction).)

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 results from repeated determinations 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