Page:NIOSH Manual of Analytical Methods - 2507EGDN.pdf/2

 EGDN: METHOD 2507, Issue 2, dated 15 August 1993 - Page 2 of 4 REAGENTS: 1. 2.

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4. 5.

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EQUIPMENT:

Ethanol, absolute. Nitroglycerin (NG)* - one of the following: a. pure material. b. standard solution in ethanol, available from dynamite manufacturer. c. tablets, sublingual, USP (analyzed; 80 to 112% NG). NOTE: to prepare solutions, weigh, crush and extract with ethanol. Filter and dilute to volume. d. nitroglycerin lactose trituration, available from NG tablet manufacturer. Ethylene glycol dinitrate (EGDN)* - one of the following: a. pure material. b. dynamite, analyzed, available. NOTE: Dynamite is heterogeneous. Use care to obtain representative sample. Argon/methane, 95:5 (v/v), purified. DE stock solution, 3 µg/µL. Dissolve 30.0 mg NG and/or 30.0 mg EGDN in ethanol to make 10 mL solution. Calibration stock solution, 0.3 µg/µL. Dilute 1 mL DE stock solution to 10 mL with ethanol.

1. Sampler: glass tube, 10 cm long, 8-mm OD, 6-mm ID, flame-sealed ends and plastic caps, containing two sections of 35/60 mesh Tenax-GC resin (front = 100 mg; back = 50 mg), separated by a urethane foam plug. Silylated glass wool plugs precede the front section and follow the back section. Pressure drop across the tube at 1 L/min airflow must be less than 3.4 kPa. Tubes are commercially available. 2. Personal sampling pump, 0.2 to 1 L/min, with flexible connecting tubing. 3. Gas chromatograph, ECD, integrator and column (page 2507-1). 4. Vials, 5-mL, with PTFE-lined caps. 5. Syringe, 10-µL, readable to 0.1 µL. 6. Pipets, 2-mL, delivery, glass, with pipet bulb. 7. Volumetric flasks, 1- and 10-mL.

See SPECIAL PRECAUTIONS.

SPECIAL PRECAUTIONS: Ethanol is flammable and all work should be done in an exhaust hood and away from any open flame. Nitroglycerin and ethylene glycol dinitrate can be explosive in their pure forms and extreme caution should be used when handling the bulk material [5].

SAMPLING: 1. 2. 3. 4.

Calibrate each personal sampling pump with a representative sampler in line. 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 0.2 and 1 L/min for a total sample size of 3 to 100 L. Cap the samplers with plastic (not rubber) caps and pack securely for shipment.

SAMPLE PREPARATION: 5.

Place the front and back sorbent sections of the sampler tube in separate vials. Discard the glass wool and foam plugs. NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94