For Piperine, 1 mg of Piperine was accurately weighed and dissolved in 1 ml of HPLC grade methanol.
From this solution 100 ml was transferred to a 100 ml volumetric flask and volume was made up to 100 ml.
Volumes of 0.2, 0.4, 0.6 and 0.8 ml of this solution were transferred into 10 ml volumetric flask and volume was made up to 10 ml.