In order to have lower limits of quantification and in an
attempt to reduce the solvent volume that was employed, lower
volumes of acetonitrile were tested. When 1 mL acetonitrile was
used for pesticide elution, the recoveries were lower than when
5 and 10 mL were used (data is not shown). One mL may not be
enough to elute all the compounds retained in the sorbent. Higher
recoveries were reached when 5 and 10 mL acetonitrile were
employed. Five mL was chosen because it presented no significant
differences from 10 mL when a statistical test was carried out
(t test, P40.05) and it is cheaper, safer and environmentally
friendlier than 10 mL