National Institute for Occupational Safety and Health

“ Prepare calibration graph [peak height (mm or μS) vs. μg chloroacetic acid per sample] . Determine desorption efficiency (DE) for each batch of silica gel used for sampling in the calibration range. Prepare at least three tubes at each of five levels. a. Place silica gel from unused front section in vial. b. Inject a known amount (2 to 20 μL) of calibration stock solution, or a serial dilution thereof, onto front sorbent section with a microliter syringe. c. Cap the vial. Allow to stand overnight. ”

“ Allow refrigerated samples to equilibrate to room temperature. Transfer front sorbent section with front glass wool plug to vial. Place back sorbent section and other two glass wool plugs in separate vial. Add 2.0 mL deionized water to each vial. Cap immediately. Agitate vials in ultrasonic bath for 30 min at room temperature. Draw sample extract through 13-mm PTFE filter with 3-mL syringe.
NIOSH Manual of Analytical Methods (NMAM) , Fourth Edition, 8/15/94 CHLOROACETIC ACID: METHOD 2008, Issue 2, dated 15 August 1994 - Page 3 of 4 CALIBRATION AND QUALITY CONTROL: 10. ”

“ Chloroacetic acid is irritating to skin and mucous membranes [4] . Work with the concentrated material only in a hood.
SAMPLING: 1. 2. 3. 4.
Calibrate each personal sampling pump with a representative sampler in line. Break ends of sampler immediately before sampling. Attach sampler to personal sampling pump with flexible tubing. Sample at an accurately known flow rate between 0.05 to 0.2 L/min for a total sample size of 1 to 100 L. Cap the samplers. Pack securely for shipment. NOTE: Store samples in the dark. Refrigerate samples if stored longer than 7 days.
SAMPLE PREPARATION: 5. 6. 7. 8. ”