Define precaution for estimation of vitamin c in lemon juice?
1. Rinse all glassware with 3% metaphosphoric acid before you begin your practical and subsequently each time you wash your flasks, cylinders, etc
2. Make up all volumes with 3% metaphosphoric acid.
3. Use a stainless steel knife for cutting the lemon.
4. After cutting the lemon, immediately squeeze the juice into 6% metaphosphoric acid.