Page:NIOSH Manual of Analytical Methods - 1610.pdf/2

 ETH YL ET HER : MET HO D 161 0, Issue 3, dated 15 M arch 200 3 - Page 2 o f 4 REAGENTS:

EQUIPMENT:

1. 2. 3. 4. 5.

1.

Ca rbon Disu lfide, low ben zene grad e.* Ethyl ether, rea gen t grad e.* Helium, prepurified and filtered. Hydrogen, prepurified and filtered. Air, prepurified and filtered.


 * See SPECIAL PRECAUTIONS.

2. 3. 4. 5. 6. 7.

Sam pler: glass tube, 7 cm long, 6-mm OD, 4mm ID, flame-sealed ends with plastic caps, containing two sections of activated (600 oC) 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 must be less than 3.4 kPa at 1 L/m in airflow. T ubes are com m ercially available. Personal sampling pump, 0.01 to 0.2 L/min, with flexible connecting tubing. Gas chromatograph, FID, integrator and colum n (see pag e 1610-1). Vials, glass, 2-mL, PTFE -lined caps. Syringe, 10-µL, 25-µL, 250-µL. Flasks, volumetric 10-mL. Pipet, volumetric, 1-mL with pipet bulb.

SPECIAL PRECAUTIONS: Ethyl ether is a dangerous fire and explosion hazard (flash point = -45 oC) and tends to form explosive peroxides. Carbon disulfide is toxic and flamm able (flash point = -30 oC). Prepare samples and standards in a well-ventilated hood.

SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Break the ends of the sampler imm ediately before sampling. Attach sampler to personal sampling pump with flexible tubing. 3. Sam ple at a n ac curately kn own flow ra te betwee n 0.01 an d 0.2 L/m in for a total sam ple size of 0.25 to 3 L. 4. Ca p the sam plers. Pac k secu rely for shipm ent.

SAMPLE PREPARATION: 5. Place the front and back sorbent sections of the sampler tube in separate vials. Include the glass wool plug in the vial with the front sorbent section. 6. Ad d 1.0 m L carbon disulfide to each vial. Attac h cap to each vial. 7. Allow to stand 30 min with occasional agitation.

CALIBRATION AND QUALITY CONTRO L: 8. Ca librate daily with at leas t six wo rking standa rds from below the LOD to 10 times the LO Q. If nec ess ary, additional stand ards m ay be a dde d to exten d the calibra tion cu rve. a. Add known amounts of ethyl ether to carbon disulfide in 10-mL volumetric flasks and dilute to the mark. Prepare additional standards as needed by serial dilution. b. Analyze together with samp les and blanks (steps 11 and 12). c. Prepare c alibration graph (pe ak area vs. µg ethyl ether per sam ple).

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition