Comparison of Accelerated Solvent Extraction (ASE) and Energized Dispersive Guided Extraction (EDGE) for the analysis of pesticides in leaves

Abstract

Various techniques have been evaluated for the extraction and cleanup of pesticides from environmental samples. In this work, a Selective Pressurized Liquid Extraction (SPLE) method for pesticides was developed using a Thermo Scientific Accelerated Solvent Extractor (ASE). This instrument was compared to the newly introduced (2017) extraction instrument, the Energized Dispersive Guided Extraction (EDGE), which combines Pressurized Liquid Extraction (PLE) and dispersive Solid Phase Extraction (dSPE). We first optimized the SPLE method using the ASE instrument for pesticide extraction from alfalfa leaves using layers of Florisil and graphitized carbon black (GCB) downstream of the leaf homogenate in the extraction cell (Layered ASE method). We then compared results obtained for alfalfa and citrus leaves with the Layered ASE method to those from a method in which the leaf homogenate and sorbents were mixed (Mixed ASE method) and to similar methods modified for use with EDGE (Layered EDGE and Mixed EDGE methods). The ASE and EDGE methods led to clear colorless extracts with low residual lipid weight. No significant differences in residual lipid masses were observed between the methods. The UV-Vis spectra showed that Florisil removed a significant quantity of the lightabsorbing chemicals but GCB was required to produce colorless extracts. Recoveries of spiked analytes into leaf homogenates were generally similar among methods, but in several cases, significantly higher recoveries were observed in ASE extracts. Nonetheless, no significant differences were observed among pesticide concentrations in field samples when calculated with the isotope dilution method in which labelled surrogates were added to samples before extraction. Extraction time using the ASE methods were ~45 minutes, which is ~4.5 times longer than the EDGE methods. The EDGE methods use ~10 mL more solvent than the ASE methods. Based on these results, the EDGE is an acceptable extraction instrument and, for most compounds, the EDGE has a similar extraction efficiency to the ASE.

Metabolomics of natural samples: A tutorial review on the latest technologies

“…The extraction cell is then placed in the ASE apparatus, which exposes the sample to high temperatures and pressure, causing the solvent to extract the metabolites from the sample. After this, the isolated metabolites are collected and dried for examination [41, 42].…”

Investigating the Effects of Temperature, Relative Humidity, Leaf Collection Date, and Foliar Penetration on Leaf–Air Partitioning of Chlorpyrifos

“…Chlorpyrifos was extracted from whole leaves using the selective PLE procedure described by Kinross et al 39 First, all leaves from the sample chamber, except those set aside for foliar penetration studies, were crushed in liquid nitrogen using a mortar and pestle. A portion of the crushed leaf sample was weighed and homogenized with DE to absorb moisture.…”

Cannabis lighting: Decreasing blue photon fraction increases yield but efficacy is more important for cost effective production of cannabinoids

“…A 0.6-gram subsample of the dried flower material was transferred to an aluminum extraction cell (Q-Cup) containing a 40 μm cellulose filter base (C9) topped with a 0.25 μm membrane filter (M2). Flower samples within the cells were extracted with reagent-grade methanol (10 mL top volume, 5 mL bottom volume, 5 mL top rinse; Fisher Scientific) using an Energized Dispersive Guided Extraction (EDGE 1 ) automated solvent extraction system (CEM Co.) [54]. The temperature in the Q-Cup was maintained at 100˚C with a hold time of 3 minutes.…”