Page:NIOSH Manual of Analytical Methods - 3518.pdf/2

 PHENYLHYDRAZINE: METHOD 3518, Issue 1, dated 15 August 1994 - Page 2 of 4 EQUIPMENT:

REAGENTS: 1. 2. 3. 4. 5.

Phenylhydrazine hydrochloride*. Hydrochloric acid, concentrated*. Phosphomolybdic acid. Distilled water. Collection medium, 0.1 M HCl. Fill a 1-L volumetric flask with approximately 300 mL distilled water, add 8.6 mL concentrated HCl, mix and dilute to the mark. 6. Phosphomolybdic acid solution (PMA). Dissolve 15 g PMA in 500 mL distilled water, allow to stand one day, and filter before use through a fluted paper filter. 7. Phenylhydrazine hydrochloride stock solution. Weigh accurately 0.1 g phenylhydrazine hydrochloride into a 100-mL volumetric flask and fill to the mark with 0.1 M HCl.

1. Sampler: Glass, standard midget bubbler with a stem that has a fritted glass end. The fritted end should have a maximum pore diameter of approximately 170 to 220 µm. 2. Personal sampling pump, 0.2 to 1 L/min, with flexible connecting tubing. The sampling pump is protected from splashover or water condensation by a 5-cm (6-mm ID and 8-mm OD) glass tube loosely packed with glass wool and inserted between the exit arm of the bubbler and the pump. 3. Spectrophotometer, visible, 730 nm, with cuvettes, 1-cm. 4. Volumetric flasks, 1000-, 100-, 50-, and 10-mL. 5. Pipets, glass, 1-, 2-, 3-, 6-, 9-, and 10-mL, delivery, with pipet bulb. 6. Graduated cylinders, glass, 10- and 25-mL.

See SPECIAL PRECAUTIONS.

SPECIAL PRECAUTIONS: Concentrated hydrochloric acid is extremely corrosive; handle while wearing acid-resistant gloves, apron, and full face shield with goggles. Phenylhydrazine is viewed as a potential carcinogen [6,7] and should be handled in a hood. Exposure to phenylhydrazine has caused hemolytic anemia [6,7]. Phenylhydrazine is a highly reactive reducing agent, and contact with oxides of copper or iron and manganese, lead, copper, or their alloys can cause fires and explosions [7]. Phenylhydrazine will attack cork, some forms of plastics, coatings, and rubber [7].

SAMPLING: 1. 2. 3. 4.

Calibrate each personal sampling pump with a representative sampler in line. Transfer 15 mL 0.1 M HCl into each bubbler. Connect the bubbler to trap and trap to pump with flexible tubing. Sample at an accurately known flow rate between 0.2 and 1 L/min for a total sample size of 25 to 120 L. After sampling, tap bubbler stem gently against inside wall of bubbler bottle to recover as much sampling solution as possible. Wash stem with 5 mL distilled water and add wash to bubbler. Prior to shipping, seal bubblers with a hard, non-reactive stopper (preferably PTFE or glass).

SAMPLE PREPARATION: 5. 6. 7. 8.

Transfer liquid from bubbler to a 50-mL volumetric flask. Rinse bubbler twice with 5 mL distilled water. Add rinses to volumetric flask. Add 10 mL phosphomolybdic acid solution to volumetric flask and dilute to mark with distilled water. Pipet a 3-mL aliquot into a 10-mL volumetric flask and dilute to mark with distilled water.

CALIBRATION AND QUALITY CONTROL: NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94