Page:NIOSH Manual of Analytical Methods - 2014.pdf/2

 p-Chlorophenol: METHOD 2014, Issue 2, dated 15 August 1994 - Page 2 of 4 EQUIPMENT:

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

6.

p-Chlorophenol 99%.* Acetonitrile, distilled in glass. Hexane, distilled in glass. Water, HPLC quality. p-Chlorophenol stock solution, 20 mg/mL. Dissolve 500 mg p-chlorophenol in 30% (v/v) acetonitrile in water to make 25 mL solution. Stable at least 3 months in airtight container. DE stock solution, 5 mg/mL. Dissolve 125 mg p-chlorophenol in hexane to make 25 mL solution.



See SPECIAL PRECAUTIONS.

1. Sampler: Pyrex tubes, 7 cm long with a 6-mm OD and a 4-mm ID, flame sealed at both ends. Each tube contains two sections of 20/40 mesh silica gel (a 150-mg sorbing section and a 75-mg backup section separated and held in place with glass wool plugs). Tubes are commercially available (SAC, Inc. 226-10 or equivalent.) 2. Personal sampling pump, calibrated, capable of operating 8 hours at 0.05 to 0.2 L/min with flexible connecting tubing. 3. HPLC with UV detector (280 nm), C18 column (Variant MicroPak MCH-5 or equivalent), injector, and electronic integrator. 4. Microliter syringes, various sizes. 5. Volumetric flasks, various sizes. 6. Centrifuge tubes, 12-mL, glass with screw caps. 7. Pipette, 1- and 2-mL, and convenient sizes for making dilutions. 8. Vials, 1-mL, with caps containing PTFE-lined silicone septa. 9. Ultrasonic bath.

SPECIAL PRECAUTIONS: p-Chlorophenol is toxic by skin absorption, inhalation, or ingestion. It also is a strong irritant to tissue and is combustible with a flash point of 121 °C.

SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Immediately before sampling, break open the ends of the tube to provide openings that are at least 2-mm in diameter. Attach sampler to personal sampling pump with flexible tubing. 3. Sample at an accurately known flowrate between 0.05 and 0.2 L/min for a total sample size of 1 to 40 liters. 4. Cap the tubes, record sample identity and all relevant sample data (duration, ambient temperature and pressure). Pack securely for shipment. NOTE: Refrigerate all samples at 0 °C when stored longer than 7 days.

SAMPLE PREPARATION: 5. 6.

7. 8. 9.

If refrigerated, allow tube to equilibrate to room temperature. Transfer each section of silica gel in a sorbent tube to a separate 12-mL centrifuge tube. Combine the glass wool plug near the inlet with the front sorbent section. Combine the two urethane foam plugs with the back section. Add 1 mL of acetonitrile, cap, and desorb in an ultrasonic bath for 30 minutes. Add 2 mL of distilled, deionized water to each tube, cap, and mix the solutions. Centrifuge the samples and transfer about 1 mL of the supernatant in each tube to a separate vial and seal with a PTFE-lined septum.

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