Take a certain amount of anionic polyacrylamide and dry it to constant weight in a drying oven at 104.5 ℃. At this time, the percentage of the mass of anionic polyacrylamide after drying in the mass of anionic polyacrylamide before drying is the solid content of anionic polyacrylamide.

Determination steps of powder sample:

1. Take out three beakers, weigh and record the mass of empty beaker to 0.0001g;

2. Put 0.6-0.8g sample into three beakers with constant weight of electronic balance, and record the mass Mo to 0.0001g;

3. Place the beaker of the sample in the 104.5 ℃ blast drying oven for drying;

4. After drying for 24h, take out the beaker and put it into the dryer. After cooling for 30min, weigh and measure the mass m to 0.0001g;

5. Calculate the solid content.