Field sampling and determination of formaldehyde in indoor air with solid-phase microextraction and on-fiber derivatization

A new sampling and analysis method for formaldehyde in indoor air was teste d in several indoor air surveys. The method was based on the use of solid-p hase microextraction (SPME) poly(dimethylsiloxane)/divinylbenzene,65 mum fi ber and gas chromatography. Indoor air surveys included grab and time-weigh ted average (TWA) sampling and were completed at six locations using (a) th e SPME method employing on-fiber formaldehyde derivatization with o-(2,3,4, 5,6-pentafluorobenzyl)hydroxylamine hydrochloride and (b)the conventional N ational Institute for Occupational Safety and Health (NIOSH) 2451 method. S ampling time for SPME fiber ranged from 10 min for grab sampling to 8 h for TWA sampling. Sampling locations included a residential house, a rental ap artment, an office building, and industrial workplaces. The air concentrati ons measured by SPME ranged from 10 to 380 ppbv and correlated well with th ose estimated by the NIOSH method. Results also indicated th at in some cas es the formaldehyde concentrations measured in residential air could be muc h higher than those allowed in occupational settings. The SPME method prove d to be accurate, fast, sensitive, and cost-efficient in field sampling app lications. This research should be of interest to research, industrial, and regulatory agencies as well as to the general public concerned with indoor air quality. Introduction