title: Preconcentration with membrane cell and adsorptive polarographic determination of formaldehyde in air.
abstract: The present paper describes a procedure that formaldehyde in air was preconcentrated in a membrane cell and its content was determined by adsorptive polarography. First the formaldehyde in air samples was preconcentrated in a membrane cell using water, then the formaldehyde reacted with 2,4-dinitrophenyl hydrazine to form 2,4-dinitrophenyl hydrazone, which can be adsorbed at the mercury electrode and yields a sensitive adsorptive polarographic wave. Over the range 6.0x10(-10)-5.0x10(-6) M, the peak currents are linearly proportional to the concentration of formaldehyde, the detection limit is 2.0x10(-10) M.
authors.affiliation: College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, People's Republic of China.
authors.forename: Zheng-Qi
authors.initials: ZQ
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Guang-Fu
authors.initials: GF
authors.lastname: He