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 indirect determination of formaldehyde as its hydrazone at a stationary hanging 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.