The OCPs were analysed using a HewlettPackard
5890 Serries II Gas Chromatographic
system (Hewlett-Packard Ltd., USA) equipped
with an on-column injector and Electron Capture
Detector. 1 µL aliquots of the sample extracts were
injected into a fused-silica capillary column
(30 m × 0.53 mm id) coated with 0.50 µm chemically
bonded HP-608 phase (Hewlett-Packard
Ltd., USA). Ultra high purity helium was used as
the carrier gas at a linear velocity of 2.2 mL min–1
and nitrogen as the auxiliary gas at a linear velocity
of 40 mL min–1. The oven temperature was
maintained at 80°C for 1 min, and then programmed
at 30°C min–1 to 180°C, at 5°C min–1 to
200°C, and at 10°C min–1 to 260°C, keeping the
final temperature for 6min. The detector was operated
at 300°C. Data was acquired and processed
with Chemstation software (Hewlett-Packard Ltd.,
USA). A typical and representative chromatogram
of a mixture of the 17 studied organochlorine pesticides
at a concentration of 10 µg mL–1 is given
in Fig. 1.