Division 4.5.2 Internal standard solution BF1

Stock solution of internal standard, e.g. estragole (concentration: 2 g/l)

Weigh 40 mg of estragole (4.3) in a 20 ml volumetric flask (400 mg in 200 ml etc.). Add some 96 % vol. ethanol (4.1) make up to volume with 45 % vol. ethanol (4.4), mix thoroughly.