Novel fully automated and parallel gas assisted dynamic accelerated solvent extractor and parallel solvent evaporator for analysis of solid and semi-solid samples

Abstract

The extraction of non-volatile and semi-volatile analytes from solid and semisolid samples has been primarily carried out via heated and/or pressurized liquid extraction mechanisms. Although analyte extraction and concentration processes have significantly evolved and currently several automated solutions are commercially available, these two steps are carried out independently. To the best of our knowledge, human intervention is always required throughout the entire process for sample extract manipulation/transportation among instruments/processes. Expectedly, excessive sample handling throughout the analytical workflow contributes to an increase in the analysis cost, the loss of analyte (s), and numerous potential analytical errors. Herein, we present the first fully automated sample-to-vial solution for analysis of non-volatile and semi-volatile compounds from solid and semisolid samples. This technological development, which is based on gas assisted dynamic accelerated solvent extraction (GA-dASE) and an integrated level-sensing system that controls the endpoint of the evaporation step, allows for fully automated analyte extraction and analyte enrichment. As a proof of concept, we applied this fully automatic extraction and enrichment system towards the quantitative determination of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs) in soil samples. Our results showed that GA-dASE not only matched the performance of the legacy accelerated solvent extraction (ASE), in terms of analyte recovery and reproducibility, but also delivered nearly 3-time reduction in labor per sample. Furthermore, our experiments demonstrated the capability of the instrument to perform fully automated extraction and evaporation steps without human intervention and with no impact on data quality (Relative Standard Deviation, RSD, ≤ 20%). In terms of interlaboratory reproducibility (n = 2), our results showed comparable results for the determination of PAHs using either 10- or 100-mL sample cells.