Anhydrous sodium sulfate analytical reagent (AR) grade (Merck, Germany) was heated in oven at 130?C for 5 h, and then was stored in 500 ml glass jars with glass stoppers in desiccator (Pragati, India).
Anhydrous sodium sulfate analytical reagent (AR) grade (Merck, Germany) washeated in oven at 130?C for 5 h, and then was stored in 500 ml glass jars with glass stoppers in desiccator (Pragati, India).