Analysis of natural-occurring and synthetic sexual hormones in sludge-amended soils by matrix solid-phase dispersion and isotope dilution gas chromatography–tandem mass spectrometry

A sensitive analytical method is presented for the simultaneous determination of four synthetic estrogens and six steroid hormones in sludge-amended soil. The method employs matrix solid-phase dispersion (MSPD) followed by isotope dilution gas chromatography-tandem mass spectrometry injecting a large volume sample (10 μL) after trimethylsilyl derivatization, using the solvent vent mode. It affords good resolution, high sensitivity and reproducibility and freedom from interferences even from complex matrices as soil amended with sewage sludge. The limits of detection (LODs) ranged from 10 to 300 pg g−1 with testosterone and progesterone having the highest limits. Soil amended with sewage sludge was spiked at 2, 10, 25 and 50 ng g−1 and the recoveries after MSPD with acetonitrile:methanol (90:10, v/v), ranged from 80 to 110% with relative standard deviations ≤9%. The method was applied to the analysis of six soil samples collected from agricultural plots and forested fields that had been amended with sewage sludge using isotopically labeled surrogates. Three of the synthetic estrogens studied were found at least in one of the six samples analyzed and trans-androsterone and estrone were the only natural hormones detected, although at very low levels (≤0.4 ng g−1).

► Analysis of synthetic and naturally-occurring sexual hormones in sludge-amended soil. ► Different GC-injection techniques and types of liners were evaluated. ► Large volume injection with solvent vent using a dimpled liner gave the best results. ► Levels of naturally-occurring hormones found in sludge-amended soils were very low.