An analytical method was developed for the determination of formaldehyde in samples of environmental origin. After a review of the current literature, five candidate methods involving chemical derivatization were chosen for evaluation. The five derivatization reagents studied were 2,4-dinitrophenylhydrazine (DNPH), 3-methyl-2-benzothiazolinone hydrazone, 2,4-pentanedione, pentafluorophenylhydrazine, and pentafluorobenzyloxyamine. The instrumental techniques used included either high performance liquid chromatography or gas chromatography, based on the nature of the derivative. After determining that the DNPH derivatization could be efficiently performed under mild reaction conditions, this method was chosen as the most appropriate of the five considered and was extensively evaluated. Optimized experimental procedures included a 1-h reaction time, followed by methylene chloride extraction and concentration of the extract. Quantification was best achieved by reverse phase liquid chromatography using absorbance detection at 360 nm. The derivatization of formaldehyde proceeded in high yield with excellent reproducibility and recovery. With the procedures employed, concentrations in the low parts per billion (ppb) range could be determined. Laboratory blank levels were in the 10- to 15-ppb range. An optimized procedure was utilized in studying several matrices, including two samples originating from the pulp and paper industry: a phenol/formaldehyde sludge and a wood dust sample containing urea/formaldehyde glue. The solid samples were extracted using the toxicity characteristic leaching procedure (TCLP) extraction method. Both matrices showed formaldehyde levels that were statistically higher than laboratory blanks. Recovery and reproducibility were excellent for the solid samples. Matrix and derivative storage problems were also evaluated.