I want to prepare 7.5 M Ammonium acetate solution. The recipe stated that I need to dissolved 57.81 g ammonium acetate in water to final volume of 100 ml, then sterilize by filtration (0.2 micro meter filter). The final pH will be 5.5. I don't understand and don't know how to sterilize by filtration? I hope someone can explain and show how to prepare this solution. Thank you