Development of automated headspace gas chromatography determination of dithiocarbamates in plant matrixes.

The determination of dithiocarbamates in plant matrixes is generally carried out by spectrophotometric (European Norm EN 12396-1, 1996) or gas chromatography headspace (European Norm EN 12396-2, 1999) methods. However, the former method presents a risk of carbon disulfide loss during hydrolysis and distillation and its sensitivity is low, whereas the latter method is time-consuming. In comparison to these European methods and in compliance with norm V03-110, we have developed an automated gas chromatography headspace method. This method offers a good level of accuracy and precision and is specific to the compound determined (CS(2)). The limit of detection is below 0.020 mg/kg and the limit of quantification is below 0.050 mg/kg. Moreover, the recovery rates are between 85 and 103% with RSD less than 20%. The automated headspace method has several advantages when compared to the spectrophotometric and manual headspace methods, including the reduction of reagents employed for extraction and a greater number of analyses achievable per day than the other methods (approximately 40 samples of food).