Page:NIOSH Manual of Analytical Methods - 5700.pdf/2

 FORMALDEHYDE ON DUST/FIBERS: METHOD 5700, Issue 1, dated 15 August 1994 - Page 2 of 5 REAGENTS: 1. 2. 3. 4. 5. 6.

EQUIPMENT:

2,4-dinitrophenylhydrazine (2,4-DNP) (1.3 g.) in 1 L. acetonitrile; 1.3 mg/mL solution. Formaldehyde stock solution, 1 mg/mL (see Appendix). Methanol, distilled in glass. Acetonitrile, distilled in glass. Water, deionized and distilled. Perchloric acid solution, 1 N. *



See Special Precautions

1. Sampler: 25-mm PVC filter (5.0-µm pore size) in a 25-mm Institute of Occupational Medicine inhalable (dust) sampler (Air Quality Research, Berkeley, CA, or equivalent). The sampler should meet the American Conference of Governmental Industrial Hygienists definition for collection of the inhalable fraction of particulate mass. [5] 2. Personal sampling pump, 2.0 L/min, with flexible polyethylene or PTFE tubing. 3. Bottles, screw-cap, low-density polyethylene (Nalgene LDPE or equivalent), 30-mL. Note: Do NOT use bottles with 'polycone' liners (source of high formaldehyde blank). 4. Liquid chromatograph with a UV detector, recorder, integrator and column (page 5700-1). 5. Tweezers. 6. Syringes, 10-, 25-, 50-, and 100-µL. 7. Volumetric flasks, 10-, 100-mL and 1 L. 8. Pipets, 0.1-, 0.5-, 1.0-, and 3-mL glass, delivery, with pipet bulb. 9. Graduated cylinders, glass, 25-mL. 10. Cotton gloves. 11. Equipment for standardizing formaldehyde stock solution, Burets, 50-mL. 12. pH meter. 13. Magnetic stirrer. 14. Beaker, 50-mL. 15. Vials, 5-mL. 16. Filters, 0.45 µm. 17. Scintillation vials, 20-mL.

SPECIAL PRECAUTIONS: Perchloric acid is a strong oxidizing agent, toxic by ingestion and inhalation and is a strong irritant. Use only in a hood. Formaldehyde is a suspect carcinogen [1,6] and should be handled in a hood.

SAMPLING: 1. 2.

3. 4. 5.

6.

Calibrate each personal sampling pump with a representative sampler in line. If gravimetric measurements are needed, handle the I. O. M. cassettes only while wearing cotton gloves. Follow NMAM 0500 [7] for pre- and post-collection weighing procedure. Place the cassette containing a 25-mm PVC 5-µm pore filter in the filter holder. Attach outlet of filter holder to the sampling pump. Sample 240 to 1050 L of air at 2.0 L/min flow rate. Transfer cassette from filter holder carefully to a 30-mL LDPE screw-cap bottle while wearing cotton gloves and seal the bottle. Ship in a suitable container in order to prevent damage during transit and keep bottles upright. Collect a bulk sample (ca. 1 g) of the dust/fiber in a glass vial and ship separately.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94