Page:NIOSH Manual of Analytical Methods - 5701.pdf/2

 RESORCINOL: METHOD 5701, Issue 1, dated 15 January 1998 - Page 2 of 4 EQUIPMENT:

REAGENTS: 1. 2. 3. 4. 5. 6.

1. Sampler: XAD-7 OVS tube, 13-mm OD, Resorcinol, reagent grade.* containing two sections of XAD-7 (200 mg front Methanol, chromatographic grade. * section/100 mg back section) separated by Helium, purified. polyurethane foam plug. A glass fiber filter Hydrogen, prepurified. precedes the front sectionand is held in place Air, filtered. with a Teflon® ring. A polyurethane foam plug Calibration stock: Dissolve mg amount of follows the back section. Tubes are resorcinol in 10 mL of solvent. Prepare commercially available (SKC # 226-57). additional standards by serial dilution. 2. Personal sampling pump, 0.2 to 1.0 mL/min, with flexible connecting tubing. 3. Gas chromatograph, flame ionization detection, integrator, and Mtx-1 capillary column (page 5701-1). 4. Ultrasonic bath. 5. Vials, autosampler, with PTFE-lined caps. 6. Vials, 4-mL, with screw caps. 7. Microliter syringes, 10-µL and other sizes as needed, readable to 0.1 µL. 8. Flasks, volumetric, various sizes. 9. Pipets, various sizes.
 * See SPECIAL PRECAUTIONS

SPECIAL PRECAUTIONS: Resorcinol is a toxic irritant and is also air and light sensitive. Methanol is flammable and a dangerous fire risk. Wear appropriate protective clothing and work with these compounds in a well ventilated hood.

SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Remove front and rear caps from each tube immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. 3. Sample at an accurately knownflow rate between 0.2 and 1.0 L/min for a total sample size of 5 to 160 L. 4. Cap the samplers and pack securely for shipment. Protect samplers from exposure to light.

SAMPLE PREPARATION: 5. Place front sorbent section and glass fiber filter in a 4-mL screw cap vial. Place backup sorbent section in a separate vial. Discard foam plugs. 6. Add 2 mL of methanol to each vial and cap. 7. Place vials in an ultrasonic bath for 30 min to aid desorption.

CALIBRATION AND QUALITY CONTROL: 8. Calibrate daily with at least six working standards over the range of interest. Three standards (in duplicate) should cover the range from LOD to LOQ. a. Add known amounts of calibration stock solution to methanol in 10-mL volumetric flasks and dilute NIOSH Manual of Analytical Methods (NMAM), Fourth Edition