Polychlorinated phenols in total diet

A method has been developed for the isolation, separation and determination of chlorinated phenols in total diet. The isolation takes place following acid hydrolysis of the conjugates and is performed by simultaneous extraction and distillation with water vapour and toluene. The isolated chlorophenols are removed by clean-up on a Florisil column using a mixture of 15% dichloromethane in toluene for elution. The separation and determination is carried out by capillary gas chromatography with electron capture detection. The recovery of the method ranged between 70.1 +/- 5 and 96.8 +/- 4.9% for the individual chlorophenols. The determination limits were 0.5 to 1.0 microgram.kg-1. The method was applied in a study aimed at estimating the chlorophenol burden in two population groups (children up to the age of 6 years and students up to the age of 18 years). In two successive years, 80 total diet samples were analysed. Average contents of the individual chlorophenols were from 0.7 to 33.5 micrograms.kg-1 and were higher for the dichlorophenol isomers. The calculated average daily intake ranged from 0.04 to 1.69 micrograms.kg-1 body weight for the individual phenols.