Page:NIOSH Manual of Analytical Methods - 2556.pdf/2
ISOP HO RO NE: M ETH OD 2556, Issue 1, dated 1 5 Ma rch 2003 - Page 2 of 4 EQUIPMENT:
REAGENTS: 1. 2. 3. 4. 5.
Dieth yl Ether, c hrom atog raph ic grade.* Isop horo ne.* Helium, prepurified and filtered. Hydrogen, prepurified and filtered. Air, filtered.
See SPECIAL PRECAUTIONS.
1. Sampler: glass tube, 7 cm long, 6-mm OD, 4- mm ID, flame-sealed ends, containing two sections of 20/40 mesh XAD-4 (80 mg front/40 m g back ) separated by a 2-m m urethane foam plug. A silylated glass wool plug precede s the front section and a 3-m m urethane foam plug follows the back sec tion. Pre ssu re drop a cross th e tube at 1 L/min must be less than 3.4 kPa. Tubes are comm ercially available. 2. Personal sampling pump, 0.01 to 1 L/min, with flexible connecting tubing. 3. Gas chromatograph, FID, integrator, basedeactivated inlet liner, and column Stabilwax-DA or equivalent (see page 25 56-1). 4. Vials, 2-mL, PTFE -lined caps. 5. Syringes, 250-, 25-, 10-:L, rea dab le to 0.1 µL. 6. Volumetric flasks, 10-mL. 7. Pipets, 3- and 5-mL, with pipet bulb. 8. Cold packs for shipping. 9. Mecha nical rotary m ixer.
SPECIAL PRECAUTIONS: Diethyl ether is h ighly volatile an d an acu te fire and e xplosion haza rd. W ork with it only in a hood. Isophorone is a lachrymator [2]. W ork with it should be done in a hood and caution should be taken while it is being used.
SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Break the ends of the sam pler im m ediately befo re sa m pling. Attach sampler to personal sam pling pum p with flexible tubing. 3. Sa m ple at an accurately known flow rate betwe en 0 .01 and 1 .0 L/m in for a total sam ple size of 2 to 25 L. 4. Ca p the sam plers with plastic (not rub ber) cap s and pa ck sec urely for shipm ent.
SAMPLE PREPARATION: 5. Place the front (and glass w ool plug) and back s orbent s ection s of the sam pler tube in separate vials. Discard the foam plugs. 6. Ad d 1.0 m L dieth yl ether to each vial. Attac h crim p cap to each vial. 7. Allow to stand 30 min with occasional agitation and place on a rotary mixer for 1.5 hours.
CALIBRATION AND QUALITY CONTRO L: 8. Calibrate daily with at least six working standards over the range 6 to 831µg isophorone per sample. a. Add known amounts of isophorone to a 10-mL volumetric flasks and dilute to the mark. b. Analyze together with samp les and blanks (steps 11 and 12). c. Prepare calibra tion gra ph (p eak area vs. µg isop horo ne).
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition