1.0) Description: Clear, colorless, volatile liquid.
2.0) Solubility: Sparingly soluble in water, miscible with ethanol (96per cent)
3.0) Identification
- Relative density .
- B. Refractive index .
- C. Infrared absorption spectrophotometry.Preparation Films.Comparison methylene chloride CRS.
- Heat 2 mL with 2 g of potassium hydroxide Rand 20 mL of ethanol (96 per cent) R under a reflux condenser for 30 min. Allow to cool. Add 15 mL of dilute sulfuric acid R and filter. To 1 mL of the filtrate add 1 mL of a 15 g/L solution of chromotropic acid, sodium salt R, ·2 mL of water R and 8 mL of sulfuric acid R. A violet colour is produced.2 mL of the filtrate obtained in identification test D gives reaction (a) of chlorides .
4.0) Tests
4.1) Appearance
It is clear and colourless .
4.2) Acidity
To 50 mL of methanol R previously neutralised to 0.1 mL of bromothymol blue solution Rl, add 50 g of the substance to be examined. Not more than 0.15 mL of 0.1 M sodium hydroxide is required to change the colour of the indicator to blue.
4.3) Relative density : 1.320 to 1.332.
4.4) Refractive index : 1.423 to 1.425.
4.5) Ethanol, 2-methylbut-2-ene and volatile impurities
Gas chromatography .
Test solution The substance to be examined.
Reference solution (a) Dilute 100 µL of carbon tetrachloride R (impurity A), 500 µL of chloroform R (impurity B), 3.0 mL of 2-methylbut-2-ene Rand 5.0 mL of methanolR (impurity D) to 100.0 mL with the test solution.
Reference solution (b) Dilute 2.0 mL of anhydrous ethanol R and 1.0 mL of reference solution (a) to 100.0 mL with the test solution.
Column:
– material: fused silica;
– size: l = 30 m, Ø = 0.32 mm;
– stationary phase: poly[(cyanopropyl) (phenyl)[dimethyl] siloxane R (film thickness 1.8 µm),
Carrier gas nitrogen for chromatography R.
Flow rate 1.0 ml/min, constant flow.
Split ratio 1:40.
Temperature:
| Time (min.) | Temperature (0C) | |
| Column | 0—5 | 40 |
| 5—12.5 | 40—55 | |
| 12.5—18 | 55—100 | |
| 18—20 | 100 | |
| Injection Port | 260 | |
| Detector | 300 |
Detection Flame ionisation; make-up gas flow rate: 25 ml/min.
Injection 2 µL of the test solution and reference solution (b).
Relative retention With reference to methylene chloride (retention time = about 7 min): impurity D == about 0.6; ethanol == about 0.8; 2-methylbut-2-ene == about 0.9; impurity B == about 1.7; impurity A = about 1.8.
System suitability Reference solution (b):
– resolution: minimum 3.0 between the peaks due to ethanol and 2-methylbut-2-ene;
– signal-to-noise ratio: minimum 5 for the peak due to impurity A.
Calculation of percentage contents:
– for ethanol, 2-methylbut-2-ene and impurities A and B, use the respective concentration of these substances in reference solution (b); correct the areas of the peaks in the chromatogram obtained with reference solution (b) by subtracting the area of the corresponding peak in the chromatogram obtained with the test solution;
– for any other impurity, use the concentration of impurity D in reference solution (b); correct the area of the peak due to impurity D in the chromatogram obtained with reference solution (b) by subtracting the area of the corresponding peak in the chromatogram obtained with the test solution.
Limits:
– ethanol: maximum 2.0 per cent V/V;
– 2-methylbut-2-ene: maximum 300 ppm V/V;
–impurity A: maximum 10 ppm VIV;
– impurity B: maximum 50 ppm VIV;
– sum of impurities other than ethanoland 2-methylbut-2-ene: maximum 0.1 per cent V/V;
– reporting threshold: 50 ppm V/V; the reporting threshold does not apply to impurity A.
4.6) Free chlorine
Place 5 mL in a ground-glass-stoppered tube. Add 5 mL of a 100 g/L solution of potassium iodide Rand 0.2 g of soluble starchR. Shake for 30 s and allow to stand for 5 min. No blue colour develops.
4.7) Residue on evaporation
Maximum 20 ppm.
Evaporate 50.0 g to dryness on a water-bath and dry at 100-105 °C for 30 min. The residue weighs a maximum of 1 mg.
4.8) Water
Maximum 0.02 per cent m/m, determined on 10.00 g
