LC Conditions.Analyses were carried out by using methanol/
water (70/30, v/v) as the mobile phase with a flow rate of 1 mL/
min. Fifty microliter aliquots of standard solutions of the water
sample extract were used for injection. A 25 cm×4.6 mm inner
diameter (i.d) LC column packed with 5µm Spherisorb ODS2
(Symta, Madrid, Spain) was employed.
Standard solutions containing 100 mg/L of each pesticide in
methanol were used to determine the LC retention times and peak
widths. The fractions transferred to the gas chromatograph were
fixed between the beginning and the end of the corresponding
peak.
TOTAD LC-GC Interface. (a) Description.A six-port valve
(Rheodyne 7000) placed immediately after the UV detector of the
LC system was used to transfer the LC eluent either to the TOTAD
interface or to waste. The connection between the HPLC detector
and the six-port valve was made with a stainless steel tube having