RESULTS AND DISCUSSION
Figure 5 shows the LC chromatogram obtained from sampling
50µL of a standard solution containing 100 mg/L of each of the
nine pesticides used for the experiments. This high volume
sampled can produce band broadening; however, the HPLC
system is used not as an analytical step but only for sample
preparation. On the other hand, an increase in sensitivity can be
achieved when larger volumes are sampled. Initial and final times
are listed in Table 1. The resulting volumes transferred, also listed
in Table 1, are calculated by considering that the flow in the LC
system is 1 mL/min. It should be stressed that the transferred
volumes ranged from 500 to 1400µL, with methanol/water (70/
30) as the solvent. Elimination of such high solvent volumes into
the glass liner occurs both in the evaporative mode and in the