National Institute for Occupational Safety and Health

“ Add exactly 15 mL Girard T solution to each bubbler using a 15-mL pipet. Mark the initial liquid level in the bubbler with a glass marker. Make impinger-to-trap and trap-to-sampling pump connections with flexible inert tubing. Sample at an accurately known flow rate between 0.1 and 0.5 L/min for a total sample size of 6 to 60 L. NOTE: Higher flow rates will cause frothing of the collection medium. If amount of liquid condensed in the trap is greater than 1 mL, collection efficiency of bubbler may be reduced and sample may be invalid. ”

“ Tap bubbler stem lightly against bubbler body to drain contents into the body. If necessary, bring samples up to the 15-mL mark with distilled water. Swirl bubbler to mix contents well. Do not add solution collected in the trap to the sample. Transfer a 5-mL aliquot to a 100-mL flask and bring to volume with HPLC mobile phase. NIOSH Manual of Analytical Methods (NMAM) , Fourth Edition, 8/15/93 ACETALDEHYDE: METHOD 5512, Issue 2, dated 15 August 1993 - Page 3 of 4
CALIBRATION AND QUALITY CONTROL: 6. ”