Page:NIOSH Manual of Analytical Methods - 1457.pdf/2

 ETHYL ACETATE: METHOD 1457, Issue 2, dated 15 August 1994 - Page 2 of 4 REAGENTS: 1. 2. 3. 4. 5.

EQUIPMENT:

Carbon disulfide,* chrom. grade. Ethyl acetate, reagent grade. Helium, purified. Hydrogen, prepurified. Air, filtered, compressed.



See SPECIAL PRECAUTIONS.

1. Sampler: glass tube, 7 cm long, 6-mm OD, 4mm ID, flame-sealed ends with plastic caps, 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 0.2 L/min, with flexible connecting tubing. 3. Refrigerant, bagged ("Blue Ice," or equivalent). 4. Gas chromatograph, FID, integrator and column (page 1457-1). 5. Vials, glass, 2-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.

SPECIAL PRECAUTIONS: Carbon disulfide is toxic and an acute fire and explosion hazard (flash point = -30 °C.) Use only in a hood. 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 0.2 L/min for a total sample size of 0.2 to 10 L. Cap the samplers with plastic (not rubber) caps and pack securely for shipment with bagged refrigerant.

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 1.0 mL CS 2 to each vial. Attach crimp cap to each vial. NOTE: Decane or other suitable internal standard at 0.1% v/v may be added at this step. Allow to stand 30 min with occasional agitation.

CALIBRATION AND QUALITY CONTROL: 8.

Calibrate daily with at least six working standards over the range 8 to 1000 µg analyte per sample. a. Add known amounts of analyte to CS 2 in 10-mL volumetric flasks and dilute to the mark. b. Analyze together with samples and blanks (steps 11 and 12). c. Prepare calibration graph (peak area of analyte vs. mg ethyl acetate).

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