Supercritical extraction of organochlorine pesticides from water

Abstract

Recoveries of solid phase disk extraction and supercritical fluid extraction of natural groundwater samples were compared in this study. Deionised water sample (1 dm3) was spiked with a mix of lindan (g-HCH) and its metabolites (a-HCH, b-HCH, d-HCH) at level of 2.25 ng l-1 of each component. Extraction of spiked groundwater was performed by C-18 solid phase disks. Captured analytes were eluted from the disk in two different ways: 1) eluate obtained by the use of a solvent was evaporated to dryness and then again dissolved in acetone and 2) elution with supercritical fluid (CO2). Extracts were analysed by GC-ECD and an internal standard. Recoveries of extracts achieved with supercritical elution were much better than those with classical elution with a solvent.

U ovom radu su upoređeni prinosi čvrsto fazne ekstrakcije i superkritične ekstrakcije pesticida iz vode. U 1 dm3 dejonizovane vode dodata je mešavina lindana i njegovih metabolita u koncentraciji od 2,25 ng/dm3 za svaki analit. Ekstrakcija vode je izvedena upotrebom C-18 ekstrakcionih diskova. Analiti su sa diska eluirani na dva načina: 1) eluat dobijen upotrebom rastvarača uparen je do suva i ponovo rastvoren u acetonu, i 2) elucija sa superkritičnim fluidom (CO2). Dobijeni ekstrakti su analizirani upotrebom GC-ECD i internog standarda. Prinosi dobijeni superkritičnom ekstrakcijom su značajno viši od prinosa dobijenih eluiranjem analita pomoću rastvarača.