Biomonitoring of Parabens in South Brazilian Urine Samples: A Validated SPE-LC-MS/MS Method

This study describes a method for the simultaneous parabens (PBs) quantification in 100 urine volunteers residing in Southern Brazil, using a three-step solid-phase extraction (SPE) with hydrophilic-lipophilic balance (HLB®) sorbent, with subsequent analysis by liquid chromatographytandem mass spectrometry (LC/MS-MS). This validated approach simplifies the standard five-step SPE process by eliminating the conditioning and equilibration steps. Target analytes included methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP) and butylparaben (BuP). Urine samples (1 mL) were hydrolyzed with β-glucuronidase acid solution, mixed with deuterated internal standards, and subjected to SPE. Analysis was performed using an UPLC BEH C18 column (2.1 × 100 mm, 1.7 μm), with a 6.5-min chromatographic run. Intra-assay precision was 2.8-11.6%, inter-assay precision was 0.7-7.1%, and accuracy was 94.8-111.8%. Extraction yields varied from 92.31-109.4%, with matrix effects ranging from -13.7 to -2.8. PBs were measured in all urine samples. A concerning proportion of 3% of the individuals exceeded the recommended acceptable daily intake (ADI) for PrP, indicating a potential health risk (hazard quotient ≥ 1.0). These findings provide valuable insights into human exposure to PBs in Southern Brazil, highlighting the need for further research to assess potential health risks.