Chlorinated acetic and propionic acids in pine needles from industrial areas

Concentrations of chlorinated acetic and propionic acids in pine needles from the surroundings of a pulp and paper mill and a metal reclamation plant were measured. Different ways of extraction and chromatographic separation were tried. Ultrasonic extraction with water of the powdered needles was found to be efficient. The acids were analysed as their pentafluorobenzyl esters with GC-ECD. The ECD sensitivity of the pentafluorobenzyl derivatives was good. The detection limit was below 1 ng/g for the chlorinated acetic and propionic acids. The concentrations of dichloroacetic acid and 2,2-dichloropropionic acid in fresh needles were on the 0–4 ng/g level. Monochloroacetic acid, 2-chloropropionic acid and 2,3-dichloropropionic acid were not detected. Trichloroacetic acid could not be analyzed by this method.