GB/T 3209-2009 Determination method for evaporation residue of benzene products

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Card type: Test method

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

• Standard number: GB/T 3209-2009
• Chinese name: Determination method for evaporation residue of benzene products
• English name: Method for determination the amount of distillation residual of benzene-type product
• Replacement relationship: replaces GB/T 3209—1982 "Determination method for evaporation residue of benzene products"
• Previous versions: GB/T 3209—1982
• Publication/implementation: published on 2009-07-15, implemented on 2010-04-01
• Proposed/administrated by: proposed by the China Iron and Steel Association; administrated by the National Technical Committee for Standardization of Steel
• Drafting organizations: Wuhan University of Science and Technology, Metallurgical Industry Information Standards Research Institute
• Main drafters: Zhao Minlun, He Xuanming, Chen Xiaoxia, Zhang Shaochun, Sun Wei
• Main differences from the 1982 version: added "Normative references"; modified the standard format and unit expression; updated the referenced documents

2. Scope of application and non-applicability

• Applicable: determination of evaporation residue of coking benzene, coking toluene, and coking xylene.
• Reference use: petroleum benzene products may also be used for reference.
• Not applicable: not provided in the available source.

3. Method principle

Place the sample into a distillation flask equipped with a condenser, evaporate 3/4 volume, inject the residual liquid into an aluminum dish that has been brought to constant weight, heat and evaporate to dryness in an air stream, measure the weight gain of the aluminum dish; this weight gain is the evaporation residue of the sample.

4. Reagents and materials (purity / preparation)

• General: unless otherwise specified, use only recognized analytically pure reagents and distilled water or water of equivalent purity in the analysis.
• 4.1 Acetone: GB/T 686 analytically pure.
• 4.2 Air: free of dust particles and oil mist.
• Other preparation: not provided in the available source.

5. Instruments and equipment

• 5.1 Aluminum dish: flat bottom, outer diameter 80 mm–100 mm, height 25 mm–30 mm, weight about 2 g.
• 5.2 Electric thermostatic drying oven: capable of maintaining temperature 105 ℃±3 ℃.
• 5.3 Analytical balance: sensitivity 0.0001 g.
• 5.4 Distillation apparatus: complies with the provisions of GB/T 3146.
• 5.5 Graduated cylinder: graduated cylinder of 100 mL.
• 5.6 Sealed evaporator: composed of an evaporation cover and an evaporation base plate; the cover and base are connected by screws, and after tightening there is no air leakage. The evaporation cover is made of organic glass or other transparent material; the upper parts on both sides of the evaporation cover are provided with an air inlet pipe and an air outlet pipe at opposite positions. The evaporator base plate is made of copper plate; the periphery of the plate has holes, and bolts are used to connect and seal it with the evaporation cover. The shape and dimensions of the evaporator are shown in Figure 1 (Figure 1 labels: 1— copper base plate; 2— rubber gasket; 3— bolt; 4— air inlet pipe; 5— evaporation cover; 6— aluminum dish; 7— air outlet pipe).
• 5.7 Heating device: electric thermostatic water bath or other heating device.
• 5.8 Flowmeter: upper flow limit is 0.5 m³/h (the source source-text extraction writes "0.5 m"/h", requires confirmation against the source standard (source-text extraction)).
• 5.9 Metal tongs, funnel, filter paper, desiccator, and other laboratory supplies.

6. Recommended operating conditions

• Drying/constant weight temperature: 105 ℃±3 ℃.
• Distillation rate: 4 mL/min～5 mL/min, until 75 mL distillate is reached in the graduated cylinder.
• Evaporation air flow rate: control the flow rate not to exceed 5 L/min.
• When using other methods to heat the evaporator, the temperature shall not exceed 105 ℃.
• Other conditions: not provided in the available source.

7. Sampling and sample preparation

• According to the provisions of GB/T 1999, take no less than 1000 mL representative sample from a large quantity of material.
• Sample filtration: filter the sample with medium-speed qualitative filter paper, discard the first 10 mL filtrate, and measure 100 mL of the filtered sample.

8. Analysis procedure

• 7.1 Pretreatment and constant weight of aluminum dish: before the test, first wash the aluminum dish with acetone (4.1), then rinse with distilled water, and finally wash once more with acetone. Place the aluminum dish in an electric thermostatic oven and dry at 105 ℃±3 ℃ for 1 h. After removal, place it in a sealed desiccator to cool for 30 min. Use metal tongs to take the aluminum dish to an analytical balance and weigh it, accurate to 0.1 mg. Then place it in the electric thermostatic oven again and dry at 105 ℃±3 ℃ for 30 min, cool for 30 min, weigh, until constant weight (error less than 0.002 g).
• 7.2 Distillation: filter the sample with medium-speed qualitative filter paper, discard the first 10 mL filtrate, measure 100 mL of the filtered sample, and pour it into a distillation flask. Connect the single-bulb separation tube, water cooling tube, and cowhorn tube. Heat the distillation flask with a gas burner or other method to perform distillation. The distillation rate is 4 mL/min～5 mL/min, until 75 mL distillate is reached in the graduated cylinder, then immediately remove the heat source.
• 7.3 Evaporation: use metal tongs to take the aluminum dish that has already reached constant weight and place it on a clean evaporator base plate. Pour the cooled residual liquid from the graduated cylinder into the aluminum dish, and place the graduated cylinder inverted on the aluminum dish for at least 15 s. First move the evaporator onto a water bath for heating, connect the flowmeter and air purification device as shown in Figure 2, and connect the air outlet to an exhaust port or outdoors. Place the aluminum dish into the evaporator, pour in the sample, then cover with the evaporation cover, tighten the bolts, introduce purified air, control the flow rate not to exceed 5 L/min, and heat. Air passes through from above, evaporating the sample to dryness, then continue passing air for 30 min. Note: if other methods are used to heat the evaporator, the temperature shall not exceed 105 ℃. (Figure 2 labels: 1—30% sulfuric acid bottle; 2—30% sodium hydroxide bottle; 3— empty bottle; 4— rotameter; 5— water bath; 6— aluminum dish; 7— sealed evaporator.)
• 7.4 Drying and constant weight: remove the evaporation cover, use metal tongs to take out the aluminum dish and place it in an electric thermostatic drying oven at 105 ℃±3 ℃, dry for 1 h, use metal tongs to take out the aluminum dish and place it in a desiccator to cool for 30 min, weigh, accurate to 0.1 mg, then place it in an electric thermostatic drying oven at 105 ℃±3 ℃ and dry for 30 min, weigh, until constant weight (error less than 0.002 g).

9. Qualitative and quantitative determination and calculation formula

The evaporation residue of the sample (m) is calculated according to formula (1):

m = m₁ − m₀ ………………（1）

Where:

• m—— evaporation residue of the sample, in milligrams per 100 milliliters (mg/100 mL);
• m₁——mass of the aluminum dish and residue, in milligrams (mg);
• m₀——mass of the aluminum dish, in milligrams (mg).

Note: The equation symbols are misaligned in the source transcription. The interpretation m = m₁ − m₀ is provisional; verify the symbols and their correspondence against the original before calculation.

10. Precision

• Repeatability (r) shall not exceed 0.4 mg/100 mL.
• Reproducibility: not provided in the available source.

11. Report

Not provided in the available source.

12. Referenced documents

• GB/T 686 Chemical reagent Acetone
• GB/T 1999 Sampling method for coking oil products
• GB/T 3146 Determination method for distillation range of benzene products
• Reference principle: for all dated referenced documents, all subsequent amendment sheets (excluding corrigenda) or revised editions are not applicable to this standard; however, parties that have reached an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For all undated referenced documents, the latest version is applicable to this standard.

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