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Pressurized hot water extraction of insecticides from process dust – Comparison with supercritical fluid extraction
Author(s) -
Eskilsson Cecilia Sparr,
Hartonen Kari,
Mathiasson Lennart,
Riekkola MarjaLiisa
Publication year - 2004
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200301566
Subject(s) - chromatography , extraction (chemistry) , carbofuran , hot water extraction , chemistry , supercritical fluid extraction , carbosulfan , solubility , supercritical fluid , analyte , supercritical carbon dioxide , high performance liquid chromatography , solid phase extraction , solvent , pesticide , organic chemistry , agronomy , biology
Pressurized hot liquid water and steam were used to investigate the possibilities of extracting insecticides (carbofuran, carbosulfan, and imidacloprid) from contaminated process dust remaining from seed‐pellet production. Extraction temperature was the most important parameter in influencing the extraction efficiency and rate of extraction, while varying the pressure had no profound effect. A clean‐up procedure of the water extracts using solid phase extraction (SPE) was found to be necessary prior to final analysis by high‐performance liquid chromatography (HPLC). Quantitative extraction (compared to a validated organic solvent extraction method) of imidacloprid was obtained at temperatures of 100–150°C within 30 min extraction time. Temperatures above 150°C were required to extract carbofuran efficiently. The most non‐polar analyte of the investigated compounds, carbosulfan, gave no detectable concentrations with pressurized hot water extraction (PHWE). One reason might be its low solubility in water, and when attempts are made to increase its solubility by increasing the temperature it may degrade to carbofuran. This can explain recovery values above 100% for carbofuran at higher temperatures. A comparison of the PHWE results and those obtained with supercritical fluid extraction (SFE) revealed that PHWE is advantageous for polar compounds, where the solubility of the analyte in water is high enough that lower temperatures can be used. For non‐polar compounds carbon dioxide based extraction is preferred unless the target analyte is highly thermostable.