Indirect determination of formaldehyde by alternating-current voltammetry at a hanging mercury drop in the presence of oxygen

An alternating-current voltammetric procedure has been developed for the in direct determination of formaldehyde as its hydrazone at a stationary hangi ng mercury drop over the formaldehyde concentration range from 0.2 to 15 mg /L in a buffer solution of pH 5.6 +/- 0.4 without removing dissolved oxygen . An EKOTEST-VA miniature voltammetric analyzer connected to a computer was used. The detection limit for formaldehyde in the proposed procedure was 0 .2 mg/L.