7. Reagents and Materials
7.1 Heptane, clean commercial or reagent grade.
NOTE 4—Warning: Flammable. Harmful if inhaled.
7.2 Acetone, clean commercial or reagent grade.
NOTE 5—Warning: Extremely flammable.
7.3 Lintless Filter Paper, (5 6 1 µm retention).
7.4 Certified Reference Materials.