Page:NIOSH Manual of Analytical Methods - 3502.pdf/2

 PHENOL: METHOD 3502, Issue 2, dated 15 August 1993 - Page 2 of 3 EQUIPMENT:

REAGENTS: 1. 2. 3. 4.

5.

6. 7. 8.



Phenol.* Water, distilled. Sulfuric acid, conc. Calibration stock solution, 0.5 mg/mL. Dissolve 50 mg phenol (accurately weighed) in 0.1 N sodium hydroxide in a 100-mL volumetric flask. Dilute to 100 mL. Collection medium, 0.1 N sodium hydroxide. Dissolve 4.0 g sodium hydroxide in distilled water. Dilute to 1 L. Nitroge or Helium, purified. Hydrogen, purified. Air, filtered, compressed.

See SPECIAL PRECAUTIONS.

1. Sampler: glass midget bubbler.* 2. Personal sampling pump, 0.2 to 1 L/min, with splashover protection and flexible connecting tubing. 3. Gas chromatograph with glass-lined injection port, FID, integrator and column (page 3502-1). 4. Syringe, 10-µL, readable to 0.1 µL. 5. Volumetric flasks, 25- to 100-mL.* 6. Pipets, 0.1-, 0.5-, 1-, 2-, 4-, 8-, and 15-mL, graduated in 0.1-mL increments, with pipet bulb.* 7. pH paper. 8. Glass wool. distilled water.
 * Wash with detergent; rinse thoroughly with

SPECIAL PRECAUTIONS: Phenol is a severe poison and is corrosive [3]. Use protective equipment when handling. All work should be performed in a hood.

SAMPLING: 1. 2. 3. 4. 5.

Calibrate each personal sampling pump with a representative sampler in line. Pipette 15 mL 0.1 N sodium hydroxide into each midget bubbler. Connect a splashover tube between the midget bubbler and the personal sampling pump using short pieces of flexible tubing. Sample at 0.2 to 1 L/min for a total sample size of 26 to 240 L. After sampling, remove and tap the bubbler stem gently against the inside wall of the bubbler bottle. Rinse the stem with 1 mL distilled water, adding the wash to the bubbler. Seal the bubbler with a hard, non-reactive stopper (PTFE or glass, not rubber) to prevent leakage during shipping.

SAMPLE PREPARATION: 6. 7. 8. 9.

Transfer the solution from the bubbler to a 25-mL volumetric flask. Rinse the bubbler twice with 1 mL distilled water and add the rinses to the flask. Add 0.1 mL conc. H 2SO 4 to the flask and mix. Use pH paper to make sure that the pH is less than 4. Dilute to the mark with distilled water and mix.

CALIBRATION AND QUALITY CONTROL: 10.

Calibrate daily with at least five working standards covering the range of the samples: a. Pipet, e.g., 0, 0.5, 1.0, 2.0, 4.0, 8.0 and 15 mL calibration stock solution into 25-mL volumetric flasks. Add the appropriate amount of 0.1 N sodium hydroxide with a graduated pipette to reach a 15-mL volume for each of the working standards. b. Add 0.1 mL conc. H 2SO 4 to each standard. Make up to 25 mL with distilled water. c. Check the solution with pH paper to make sure that its pH is less than 4. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/93