ADSORPTION VOLTAMMETRIC DETERMINATION OF MU-G L(-1) LEVELS FORMALDEHYDE VIA IN-SITU DERIVATIZATION WITH GIRARDS REAGENT-T

The adsorptive voltammetric behaviour of formaldehyde (HCHO) after its in situ derivatization with trimethylaminoacetohydrazide chloride (Gi rard's reagent T) at a hanging mercury drop electrode (HMDE) was inves tigated in NH3-NH4Cl (pH 9.7) solution. The results showed that the ad duct of HCHO with Girard's reagent T can be adsorbed on the surface of the HMDE, yielding one peak at -1280 mV (vs Ag/AgCl electrode), corre sponding to the reduction of the adduct. The limit of detection was as low as 8.0x10(-8) mol dm(-3) (corresponding to 2.4 mu g dm(-3) of HCH O). The linear range of the method was 2.0x10(-7)similar to 8.0x10(-6) mol dm(-3). The sensitivity of the method allows its application for the direct determination of HCHO in rain water samples.