RIBAVIRIN: METHOD 5027, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2. 3.
4.
5.
EQUIPMENT:
Ribavirin,* reagent grade. H2SO 4,* conc. Mobile phase: Add conc. H 2SO 4,* to deionized, distilled water until pH is 2.5 ±0.1 as measured by a pH meter. Calibration stock solution: Dilute 5 mg Ribavirin to 10 mL in a volumetric flask using mobile phase as solvent. Prepare fresh daily. Standard buffer solutions (pH 7.00 and 3.00) for calibrating pH meter. Available as a reference standard from USP (Cat. No. 60270-6).
See SPECIAL PRECAUTIONS.
1. Sampler: 1-µm, 37-mm glass fiber filter (Type A/E; Cat. No. 61652, Gelman Sciences, Inc., Ann Arbor, MI 48106, or equivalent) with a cellulose backup pad in a 2-piece cassette. 2. Personal sampling pump capable of operating for 8 hours at 1 to 4 L/min, with flexible connecting tubing. 3. High performance liquid chromatograph, isocratic, with water jacket (or equivalent) to maintain column temperature at 65 °C; UV detector (210 nm); peak integrator; and cation exchange resin column (Cat. No. HPX-87H, Bio-Rad Laboratories, Richmond, CA 94804 or equivalent). 4. Vials, 10-mL, glass with PTFE-lined caps. 5. Culture tubes, PTFE-lined screw caps, 13-mm x 100-mm. 6. Syringe filters, disposable, 0.45-µm pore size, for filtering samples. 7. Pipets, 1- to 10-mL. 8. Volumetric flasks, 10-mL. 9. Forceps. 10. Shaker, mechanical, wrist-action 11. pH meter.
SPECIAL PRECAUTIONS: Ribavirin has been found to be teratogenic in animals. [4, 5] Use protective gloves when handling. Work only in a fume hood. Women of childbearing age should exercise extreme caution. Avoid skin contact with concentrated sulfuric acid.
SAMPLING: 1. 2. 3. 4.
Calibrate each personal sampling pump with a representative sampler in line. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 1 and 4 L/min for a total sample size of 5 to 1000 L. Avoid overloading the filter (ca. 2 mg total dust maximum loading). Seal the samplers and pack securely for shipment. Collect a bulk sample (ca. 1 g) in a glass vial and ship it separately.
SAMPLE PREPARATION: 5. 6.
7.
Carefully remove the filter from the cassette. Use forceps to fold the filter in half, and insert into a culture tube. Discard the backup pad. Add 3 mL mobile phase. Seal tightly with screw cap and agitate samples with a shaker for 30 minutes. NOTE: Although Ribavirin is stable as a solid, it degrades after 12 h in the mobile phase necessitating daily preparation of standards and prompt analysis of extracted samples [3]. Filter the sample solution through a syringe filter.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
