National Institute for Occupational Safety and Health

“ Calibrate each personal sampling pump with a representative sampler in line. Transfer 10 mL 0.1 M hydrochloric acid to a bubbler. Connect outlet arm of bubbler to the glass-wool-packed tube (to prevent splashover into the pump) and then to the sampling pump with the flexible tubing. Sample at an accurately known rate of 0.2 to 1.0 L/min for total sample size of 2 to 100 L. Remove bubbler stem and rinse with 2 mL of 0.1 M hydrochloric acid into bubbler body. Seal bubbler with an inert stopper for shipment in a suitable container in order to prevent damage during transit. ”

“ Add appropriate aliquots (10, 20, 30, 40 and 50 μL) of calibration stock solution to 10 mL of 0.1 M hydrochloric acid in 50-mL volumetric flasks. Prepare a reagent blank using only 10 mL of 0.1 M hydrochloric acid. Treat with (steps 7 and 8) phosphomolybdic acid solution. Analyze working standards together with samples and reagent blanks (steps 10 through 12) on a spectrophotometer at 730 nm, using a 1-cm cell. Correct standards for reagent blank absorbance. Prepare a calibration graph of absorbance vs. amount (μg) of 1,1-dimethylhydrazine per 50 mL of sample. ”

“ Graduated cylinders, glass, 10-mL, 25-mL. 11. Water bath at 95 °C. 12. Stopwatch. 13. Thermometer, ca. 0-120 °C.
See SPECIAL PRECAUTIONS.
SPECIAL PRECAUTIONS: 1,1-Dimethylhydrazine may be fatal if inhaled, swallowed or absorbed through the skin [5] . Contact may cause burns to skin and eyes. Vapor may be irritating to the eyes, skin, and mucous membranes. Handle with caution and use appropriate protective equipment. ”