Comparison of Accelerated Solvent Extraction, Soxhlet and Sonication Techniques for the Extraction of Estrogens, Androgens and Progestogens from Soils

摘要

Leaching of hormones from manure amended fields to receive surface water can lead to endocrine disruption in resident fish populations. In order to determine the concentrations of hormones present in manure amended soils, and thus the potential for soils to release hormones to aquatic environments, efficient extraction methods are needed. In this study, the efficacy of three techniques (accelerated solvent extraction [ASE], Soxhlet and sonication) for the extraction of estrogens, androgens and progestogens, as well as their metabolites, from various soil types were evaluated. The stability of hormones spiked into these soils and stored for 30, 90 and 210 days at -20°C was also investigated. Four experimental soil matrices (reagent sand, silt loam, clay and high organic) were spiked with 50 μL of 10 μg·mL-1 (in methanol;final conc. 100 ng·g-1) of a stock mix of hormones and isotopically-labeled standards (ISTDs). After equilibration, triplicate samples of the spiked soils were extracted by ASE, Soxhlet and sonication techniques and analysed, without post extraction cleanup, using HPLC-MS/MS. Sonication and ASE were effective at extracting hormones from all matrices with overall average apparent recoveries, for all 19 extracted analytes, of 71% ± 23% and 73% ± 16%, respectively. Soxhlet was significantly less efficient (p < 0.05) with overall average apparent recoveries of 58% ± 34%. Incorporation of ISTDs resulted in overall average process efficiencies of 108% ± 24%, 102% ± 24% and 180% ± 310% for ASE, Soxhlet and sonication, respectively. The hormones had variable stability in soils stored for at least 30 days, and therefore it recommended that soil samples be analysed within 30 days of sampling.