摘要：A screening method was established for the determination of 27 pesticides in fresh fruits and vegetables by a super critical fluid extraction (SFE), cleaned up with cartridge columns and HPLC. The multiresidue and semiautomatic analysis was useful for a screening examination, because the determination methods for pesticides under the Japanese Food Sanitation Law are mostly individual determinations. Reported methodologies for multiresidue analysis by HPLC were not adequate to regulated pesticides in Japan. In this report, multiresidue determination of pesticides and their metabolites are discussed using SFE and HPLC. Details of the proposed method are as follows : Wet samples such as fruits and vegetables were not suitable for the SFE instrument, so the water in the samples was removed with an absorptive polymer (Arasorb[○!R] S-310) prior to SFE. The pesticides were extracted by SFE, the extracts trapped with Extrelut[○!R] NT + Bond Elut[○!R] C18 and then eluted with acetonitrile. The eluate was cleaned up with Sep-Pak[○!R] Florisil+Bond Elut[○!R] PSA cartridges. After washing with n-hexane, the pesticides were eluted from the cartridges with 15% ether/n-hexane, 15 and 50% acetone/n-hexane. These three fractions were individually determined by HPLC with a photodiode-array detector. The pesticides spiked in samples at 0.5ppm showed satisfactory recoveries except for thiabendazole, imazalil and clofentezine. Detection limits were 0.005-0.01ppm for the 27 pesticides.
Loading...
