Abstract
A sensitive and simple coulometric method has been developed for the determination of hydrazine and monomethylhydrazine (MMH) in solution. This coulometric method can readily be used in conjunction with impingers to measure the amount of hydrazine and MMH in air. The method has a limit of detection of less than 25 ng of hydrazine or MMH in 40 mL of solution, which corresponds to less than 2 ppb in 10 L of air. External standards are not necessary as calibration can be performed electronically. The dynamic range of the coulometric method extends from 25 ng to greater than 2500 ng in 40 mL of solution. At the higher concentrations the relative standard deviation was about 2%. The method gave excellent agreement with the two current National Institute for Occupational Safety and Health approved methods at the higher end of this concentration range.