National Institute for Occupational Safety and Health

“ Calibrate daily with at least six working standards over the range of 10 to 4500 μg per sample. a. Add known amounts of methyl cellosolve acetate to 1 mL eluent in sample vials. b. Analyze together with samples and blanks (steps 11 and 12) . c. Prepare calibration graph (peak area or ratio of peak area of analyte to peak area of internal standard vs. μg methyl cellosolve acetate) . Determine desorption efficiency (DE) at least once for each batch of charcoal used for sampling in the calibration range (step 8) . Prepare three tubes at each of five levels plus three media blanks. ”

“ A 30-m x 0.32-mm fused silica capillary column coate d internally with 1.0 μm of DB-5, with appropriate instrument conditions, is recommended.
INTERFERENCES: High humidity conditions may cause inefficient collection of organic vapors. ”