High-throughput analysis of emerging contaminants in biosolids, composts and soils using liquid chromatography coupled to high resolution orbitrap mass spectrometry.

A novel multiresidue analytical method was developed for profiling contaminants of emerging concern (CEC) in biosolids, manure, compost, and soil. These CEC are often inadequately characterized and unregulated. They include pharmaceutical and personal care products (PPCP), plastic-related compounds, industrial antioxidants, artificial sweeteners, and pesticides. The method used ultrasound-assisted extraction (UAE) and a tiered evaluation of 22 extraction solvents, multiple mobile phases, and an online solid-phase extraction (online-SPE) cleanup step integrated into the ultra-high-performance liquid chromatography system coupled with high-resolution mass spectrometry (Orbitrap) via heated electrospray ionization (UHPLC-HESI-HRMS Orbitrap). In total, 17 sewage sludge/biosolid samples, 15 manure/compost samples, and 18 soil samples were analyzed for 74 target compounds. The developed method exhibited high selectivity, satisfactory recoveries of 70-120% for 86% of the analytes, precise results with a relative standard deviation (RSD) < 20% for 93% of the analytes, and acceptable trueness ranging from 80 to 123%. The detection limits (LODs) ranged from 0.001 to 0.81 ng g-1, which are better than or comparable to those reported previously. Benzothiazole (BTH), 1H-benzotriazole (BTR), N,N-diethyl-m-toluamide (DEET), 1,3-diphenylguanidine (DPG), hydroxyatrazine (OH-ATZ), caffeine (CAF), carbamazepine (CBZ), and venlafaxine (VNX) were detected in 50% of the samples analyzed. Transformation products (TPs), including desnitro-imidacloprid (DN-IMI) and OH-ATZ, were quantified in biosolids for the first time. The findings indicate that sewage sludge is a major reservoir of CEC, followed by manure/compost, warranting further investigation for monitoring and regulation. Non-parametric testing revealed significant matrix-dependent concentrations for antihistamines (ε2 = 0.31), β-blockers (ε2 = 0.23), industrial chemicals (ε2 = 0.21), antidepressants (ε2 = 0.18), and artificial sweeteners (ε2 = 0.14).