Page:NIOSH Manual of Analytical Methods - 2539.pdf/2

 ALDEHYDES, SCREENING: METHOD 2539, Issue 2, dated 15 August 1994 - Page 2 of 10 EQUIPMENT:

REAGENTS: 1. 2.

3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23.

Toluen e, chrom atograp hic quality. 2-(Hydro xyme thyl) piperidine. R ecrystallize seve ral tim es fr om isooc tane until th ere is one major peak (>95% of area) by GC analysis. Store in desiccator. Amberlite XAD-2 (Rohm and Haas or equivalent). Form aldeh yde, * 3 7% (w/v) solut ion in water. Formaldehyde stock solution, 1 :g/:L (see APPEND IX A). Acetaldehyde *. Acrolein*. Propionaldeh yde*. Butyraldehyde*. Isobutyraldehyde*. Crotonaldeh yde*. Valeraledehyde *. Isovaleraldehyde*. Hexana l*. Heptana l*. Furfural*. Sulfuric acid, 0.02 N. Sodium hydroxide, 0.01 N. Sodium sulfite, 1.13 M. Water, deionezed, then distilled. Hydrogen, prepurified. Air, filtered, com presse d. Helium, purified.
 * See SPECIAL PRECAUTIONS

1.

2. 3.

4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17.

Sampler: glass tube, 10 cm long, 6-mm OD, 4-m m ID ; flam e-se aled e nds and p lastic caps, containing two sections of 40/60 mesh, 2-(hydroxymethyl) piperidine-coated XAD-2 (front = 120 mg; back = 60 mg: see APPENDIX A) retained and separated by sma ll plugs of silan ized glass wool. Pres sure drop acro ss th e tub e at 0 .10 L /min airflow must be less than 760 kPa (5.7 mm Hg). Tub es ar e com me rcially a vailab le (Supe lco, Inc. O RBO -23 or eq uivalent). Personal sampling pump, 0.01 to 0.05 L/min, with flexible connecting tubing. Gas chromatograph, flame ionization detector (FID), integrator and column (page 2539-1). GC/MS system for confirmation. Ultrasonic bath. Vials, glas s, 1-m L, with PTF E-line d crim p caps. Flasks, volumetric, 10-mL. Pipets, molumetric, 1-mL with pipet bulb. Syringes, 10-:L (readable to 0.1-:L), 25-, and 50-:L. File. Beakers, 50-mL. pH me ter. Magnetic stirrer. Burets, 50-mL. Flasks, round-bottomed, 100-mL. Soxhlet extraction apparatus. Vacuum oven. Distillation apparatus.

SPECIAL PRECAUTIONS: Aldehydes can irritate the mucous membranes and act on the central nervous system [3]. Certain aldehydes are also suspect carcinogens. Work with these compounds only in a well-ventilated hood. SAMPLING: 1. 2. 3.

Calibrate each personal sampling pump with a representative sampler in line. Break ends of the sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. For general screening, sample at 0.01 to 0.05 L/min for a maximum sample volume of 5 L. NOTE: Aldehydes react with the 2-(hydroxymethyl)piperidine to form an oxazolidine derivative in the sorb ent b ed d urin g sa mp ling. S am pling rate is lim ited b y the spe ed o f this reaction. Owing to the lower reactivities of some aldehydes, sampling even at 0.02 L/min may cause breakthrough because of incomplete reaction.

SAMPLE PREPARATION:

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition