Page:NIOSH Manual of Analytical Methods - 2543.pdf/2

 HEXACHLOROBUTADIENE: METHOD 2543, Issue 2, dated 15 August 1994 - Page 2 of 3 REAGENTS: 1. 2. 3. 4. 5.

EQUIPMENT:

Hexane (spectrographic grade). Hexachlorobutadiene, 98+ purity. Argon, high purity. Methane, high purity. Hexachlorobutadiene calibration stock solution (16.7 mg/mL): Dilute 1 mL (1.67 g) hexachlorobutadiene to 100 mL with hexane.



See SPECIAL PRECAUTIONS.

1. Sampler: glass tube, 7 cm long, 8-mm OD, 6mm ID, with plastic caps, containing two sections of 20/50 mesh XAD-2 (front = 150 mg; back = 75 mg) separated and held in place by plugs of silylated glass wool. Pressure drop across the tube must be <3.4 kPa (2.5 cm Hg) at 1 L/min airflow. 2. Personal sampling pump, 0.05 to 0.2 L/min, with flexible tubing. 3. Gas chromatograph with 63 Ni ECD. 4. Capillary column (Nukol, or equivalent) 5. Vials, glass, 4 mL, with PTFE-lined caps. 6. Microliter syringes (10-µL, 25-µL, etc.) 7. Pipettes (1-mL, 2-mL, etc.) 8. Ultrasonic bath.

SPECIAL PRECAUTIONS: Hexachlorobutadiene is a toxic material. Exercise all appropriate safety precautions.

SAMPLING: 1. 2. 3. 4.

Calibrate each personal sampling pump with a representative sampler in line. Break open the ends of sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurate flow rate between 0.05 and 0.2 L/min for a total sample size of 1 to 100 L. Cap the samplers with plastic caps and pack securely for shipment.

SAMPLE PREPARATION: 5. 6. 7.

Place the front and back sections of the sorbent tube in separate 4 mL vials. Discard glass wool plugs. Add 2.0 mL hexane to the vials containing the front sections and 1.0 mL hexane to vials containing the backup sections. Desorb each vial for 1 h in an ultrasonic bath. Transfer 1 mL aliquots to 13-mm autosampler vials for analysis.

CALIBRATION AND QUALITY CONTROL: 8. a. b. c. 9.

a. b.

Calibrate daily with at least six working standards over the range of 0.02 µg to 6 µg per sample. Add appropriate aliquots of calibration stock solution to hexane in 10-mL volumetric flasks and dilute to mark. Analyze working standards together with samples and blanks (steps 11 and 12). Prepare a calibration graph of peak area vs. µg of hexachlorobutadiene per sample. Determine desorption efficiency (DE) at least once for each lot of XAD-2 used for sampling in the concentration range of interest. Prepare three tubes at each of five levels, plus three media blanks. Remove and discard the back sorbent section of a sampler. Inject a known amount (e.g., 1 to 20 µL) of calibration stock solution, or a dilution thereof in hexane, directly onto the front section with a microliter syringe. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94