Page:NIOSH Manual of Analytical Methods - 2501.pdf/2

 ACROLEIN: METHOD 2501, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2. 3.

4.

5.

EQUIPMENT:

Toluene, chromatography quality. Acrolein,* freshly distilled under N 2 to remove stabilizer. Store at 0 °C. 2-(Hydroxymethyl)piperidine. Recrystallize several times from isooctane until pure by GC analysis. Store in dessicator. XAD-2 (Amberlite - Rohm and Haas) or equivalent. Extract 4 h in soxhlet with 50/50 (v/v) acetone/methylene chloride. Replace with fresh solvent and repeat. Vacuum dry overnight. Calibration stock solution, 1.0 µg/µL. Add 11.9 µL acrolein to a septum-capped 10-mL volume of toluene.


 * See Special Precautions

1. Sampling tube: glass tube, 10 cm x 4-mm ID, containing a 120-mg front section and a 60mg back-up section of the 2-(hydroxymethyl) piperidine-coated XAD-2 (see APPENDIX) with flame-sealed ends. Sorbent sections are retained and separated by small plugs of silanized glass wool. Pressure drop ca. 2.2 inches of water (756 Pa) at 0.10 L/min. Tubes are commercially available (Supelco ORBO 23 or equivalent). 2. Sampling pump, 0.01 to 0.1 L/min, with flexible connecting tubing. 3. Vials, 4-mL, with septum and plastic screw caps. 4. Ultrasonic bath. 5. Pipettes, volumetric, 1- and 2-mL, with pipet bulb. 6. Flasks, volumetric, 10-mL. 7. Pipettes, disposable, 2-mL. 8. Syringes, 10-µL (readable to 0.1 µL) and 25and 50-µL. 9. Gas chromatograph, nitrogen-specific detector, integrator and column (page 2501-1). 10. File.

SPECIAL PRECAUTIONS: Acrolein is an acute irritant and a potential fire hazard (flash point = -17.8 °C); work with this compound only in a hood.

SAMPLING: 1. 2. 3.

Calibrate each personal sampling pump with a representative sampler in line. Score with a file and break the ends of the sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 0.01 and 0.1 L/min for a total sample size of 1.5 to 48 L. NOTE: Sampling rate is limited by the speed of reaction of acrolein with the sorbent coating. Sampling at rates above 0.10 L/min could cause appreciable acrolein breakthrough, possibly invalidating the sample.

SAMPLE PREPARATION: 4. 5. 6. 7. 8.

Score each sampler with a file in back of the rear sorbent section. Break sampler at score line. Remove and place glass wool plug and rear sorbent section in a 4-mL vial. Transfer front section with the remaining glass wool plugs to a second 4-mL vial. Add 2.0 mL of toluene to each vial. Screw cap tightly onto each vial. Agitate vials by placing them in an ultrasonic bath for 30 min.

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