2. Apparatus
a. Spectrophotometer,having 10-mm absorption cells, a narrow (10-nm or less) spectral
band, and an effective operating range from 400 to 700 nm.
b. Filtration system,consisting of the following (see Figure 2120:1):
1) Filtration flasks,250-mL, with side tubes.
2) Walter crucible holder.
3) Glass Gooch filtering crucible with fritted disk, pore size 40 to 60 µm.
4) Calcined filter aid.*#(8)
5) Vacuum system.