Laboratory and field validation of the GC-NPD method for the measurement of formaldehyde in the workplace.

Formaldehyde is classified as a suspected or probable human carcinogen by several organizations. Since conventional sampling and analytical methods for airborne formaldehyde show relatively poor sensitivity, an improved method is needed. The aim of this study was to develop a new analytical method for measuring the airborne formaldehyde concentrations in workplaces and to evaluate the performance of the method through laboratory and field tests. The method employs a sampling tube containing silica gel coated with 2, 4-dinitrophenylhydrazine (2,4-DNPH), which produces 2,4-DNPH-formaldehyde derivative with formaldehyde. Then the 2,4-DNPH-formaldehyde derivative is analyzed using gas chromatography (GC) equipped with a nitrogen-phosphorus detector (GC-NPD). In laboratory tests, the new method, referred to as the GC-NPD method, was as sensitive as the National Institute for Occupational Safety and Health (NIOSH) analytical method, which uses high-performance liquid chromatography equipped with ultraviolet det...