GB/T 6818-2019Octanol (2-Ethyl hexanol) for industrial use (English PDF)

3.1 Appearance. Transparent liquid, no suspended matter

4.1 General

The reagents and water used in this Standard, when other requirements are not specified, refer to analytically-pure reagents and grade three water that meets the requirements of GB/T 6682.

4.2 Determination of chromaticity

According to GB/T 3143.

4.3 Determination of density

According to GB/T 2013. The temperature correction coefficient K value of the sample density is 0.00073 g/(cm3·°C).

4.4 Determination of mass fraction of 2-ethylhexanol

and 2-ethyl-4- methylpentanol

4.4.1 Principle

Inject an appropriate amount of specimen into the gas chromatograph. 2- Ethylhexanol and impurities are effectively separated on a capillary column.

Use a hydrogen flame ionization detector (FID) to measure the peak area of each component. Use the corrected area normalization method to calculate the concentration of each component. After deducting the water, calculate the content of 2-ethylhexanol, 2-ethyl-4-methylpentanol and other impurities.

4.4.2 Reagents and materials

4.4.3 Instruments

4.4.3.1 Gas chromatograph. Equipped with hydrogen flame ionization detector (FID) and sample injection shunt device. The sensitivity and stability of the whole machine comply with the relevant regulations in GB/T 9722. The linear range of the instrument shall meet the requirements of quantitative analysis.

4.4.3.2 Recorder. Chromatographic data workstation.

4.4.4 Analysis steps

4.4.4.1 Determination of relative mass correction factor

4.4.4.2 Determination of sample

Start the gas chromatograph. Debug the instrument according to the chromatographic operating conditions listed in Table 2. Analyze the specimen after the baseline is stable. Use corrected area normalization method to quantify.

Calculate the content of each component. The correction factors for other unknown peaks are calculated based on 2-ethyl-4-methylpentanol.

4.4.5 Result calculation

The mass fraction w1 of 2-ethylhexanol and the mass fraction w2 of 2-ethyl-4- methylpentanol are calculated according to formula (2).

4.5 Determination of acid content (in terms of acetic acid)

4.5.1 Principle

In ethanol medium, phenolphthalein is used as indicator, and sodium hydroxide standard titration solution is used for neutralization and titration.

4.5.2 Reagents

4.5.2.1 Ethanol. 95% (volume fraction).

4.5.2.2 Sodium hydroxide standard titration solution. c(NaOH)=0.05mol/L.

4.5.2.3 Phenolphthalein indicator solution. 10g/L.

4.5.3 Instruments

Burette. 10mL; division value is 0.05mL.

4.6 Determination of the mass fraction of carbonyl compounds

4.6.1 Principle

The carbonyl compound in the sample reacts with hydroxylamine hydrochloride to form an oxime. At the same time, it releases hydrochloric acid of the same amount. Use potassium hydroxide ethanol standard titration solution to conduct potentiometric titration for free hydrochloric acid.

4.6.2 Reagents

4.6.2.1 Absolute ethanol.

4.7 Sulfuric acid color test

4.7.1 Principle

Under certain conditions, use sulfuric acid to process the specimen. Compare the color produced by the specimen with the same volume chromaticity standard.

4.7.2 Reagents

Sulfuric acid. Guaranteed reagent.

4.7.3 Test steps

Use sulfuric acid solution to clean the used instruments. Then use tap water and distilled water rinse and dry.

4.8 Determination of moisture content

4.8.1 Carl-Fischer direct coulometric titration (arbitration law)

Measure according to GB/T 6283. Measure the volume of the specimen to 10.0mL or take an appropriate volume according to the moisture content in the specimen.

7.1 Packaging

Octanol for industrial use shall be packaged in a dry, clean tanker or other packaging that meets the requirements.

7.2 Transportation

The transportation of octanol for industrial use shall comply with the relevant regulations on the transportation of hazardous chemicals. It shall be handled with care, to avoid collision. Prevent rain and sun. […]