National Institute for Occupational Safety and Health

“ Calibrate daily with at least six working standards. a. Transfer 15 mL 0.1 M HCl to a 50-mL volumetric flask. b. Pipet 1 to 10 mL of phenylhydrazine hydrochloride stock solution into the volumetric flask. c. Continue preparation as with samples (steps 7 and 8) . d. Analyze together with samples and blanks (steps 11 and 12) . e. Prepare calibration graph (absorbance vs. mg phenylhydrazine hydrochloride per sample) . Analyze three quality control blind spikes and three analyst spikes to ensure that calibration graph is in control. ”

“ Phenylhydrazine is viewed as a potential carcinogen [6,7] and should be handled in a hood. Exposure to phenylhydrazine has caused hemolytic anemia [6,7] . Phenylhydrazine is a highly reactive reducing agent, and contact with oxides of copper or iron and manganese, lead, copper, or their alloys can cause fires and explosions [7] . ”

“ Transfer 15 mL 0.1 M HCl into each bubbler. Connect the bubbler to trap and trap to pump with flexible tubing. Sample at an accurately known flow rate between 0.2 and 1 L/min for a total sample size of 25 to 120 L. After sampling, tap bubbler stem gently against inside wall of bubbler bottle to recover as much sampling solution as possible. ”