Page:NIOSH Manual of Analytical Methods - 1608.pdf/2

 GLYCIDOL: METHOD 1608, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2. 3. 4. 5.

EQUIPMENT:

Tetrahydrofuran, chromatographic quality. Glycidol, reagent grade.* Nitrogen, purified. Hydrogen, prepurified. Air, filtered.


 * See Special Precautions

1. Sampler: glass tube, 7 cm long, 6-mm OD, 4mm ID, flame-sealed ends, containing two sections of activated (600 °C) coconut shell charcoal (front = 100 mg, back = 50 mg) separated by a 2-mm urethane foam plug. A silylated glass wool plug precedes the front section and a 3-mm urethane foam plug follows 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, 0.01 to 1 L/min, with flexible connecting tubing. 3. Refrigerant, bagged ("blue ice" or equivalent). 4. Gas chromatograph, flame ionization detector, integrator and column (page 1608-1). 5. Vials, 1-mL, PTFE-lined caps. 6. Syringes, 10-µL, and other convenient sizes for preparing standards, readable to 0.1 µL. 7. Volumetric flasks, 10-mL. 8. Pipet, 0.5-mL.

SPECIAL PRECAUTIONS: Glycidol is irritating to the upper respiratory tract, skin, and mucous membranes and will attack some forms of plastics, rubber and coatings [3]. It is absorbed through skin [4].

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 0.01 and 1 L/min for a total sample size of 5 to 100 L. Cap the samplers with plastic (not rubber) caps and pack securely for shipment at 4 °C.

SAMPLE PREPARATION: 5. 6. 7.

Place the front and back sorbent sections of the sampler tube in separate vials. Discard the glass wool and foam plugs. Add 0.5 mL tetrahydrofuran to each vial. Attach crimp cap to each vial. Allow to stand 30 min with occasional agitation.

CALIBRATION AND QUALITY CONTROL: 8.

Calibrate daily with at least six working standards over the range 0.1 to 22 mg glycidol per sample. a. Add known amounts of glycidol to tetrahydrofuran in 10-mL volumetric flasks and dilute to the mark. b. Analyze together with samples and blanks (steps 11 and 12). NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94