How does one extract lactose from milk?
My niece who is in Secondary V is doing a science project. Basically she intends to obtain lactose from three different kinds of milk. The procedure calls for acetic acid 10%, calcium carbonate and ethanol 95%. She has been using vinegar (acetic acid 5%), calcium tablets (each contains 500mg of calcium carbonate and 125 IU (3.1 mcg)I of vitamin D) and rubbing alcohol (which lists to have 70% ethyl alcohol) and so far, she has been able to obtain the casein, the albumin but she has hardly got anything precipitated to be identified as lactose in any kind of milk. Would you think she definitely needs to get those materials in their pure chemical nature to actually obtain the lactose? If that is the case where would she be able to get them?
Extracting lactose from milk is not a simple project. I do suspect that the exact concentrations are needed i.e. you cannot substitute vinegar for the 10% acetic acid. I would suggest trying a chemical supplier to see if they sell what you need.