Título: Suspect Screening of Persistent, Mobile and Toxic Substances in the Guadalquivir River
(SW Spain)
Congreso: SETAC2025
Link: https://www.setac.org/resource/abstract-book-vienna-pdf.html
Resumen: Persistent, mobile, and toxic (PMT) substances represent a group of emerging
contaminants that pose significant challenges for water quality and human health. Due
to their polarity, mobility, and resistance to degrada on, these substances can evade
conven onal water treatment and persist in aqua c environments for extended periods,
posing a significant risk to drinking water sources.
This study inves gates the presence of PMTs in the Guadalquivir River, one of the most
significant rivers in southern Spain, which has considerable estuarine influence and is
subject to intense anthropogenic pressures and salinity gradients. A targeted field
campaign was conducted during the summer of 2024, with sampling occurring on July 3
and 30 at eight loca ons along the river’s course, from its mouth upstream. At each
loca on, grab water samples were collected from the microlayer, surface water, and
bo om.
The suspect screening approach was applied using liquid chromatography coupled to
high-resolu on mass spectrometry (LC-HRMS), based on the September 2023 update of
the German Environment Agency (UBA) list, which priori ses 259 PMT substances
registered under the European Union Registra on, Evalua on, Authorisa on, and
Restric on of Chemicals (REACH) regula on. These substances have been iden fied as
hazardous to drinking water resources and require stringent monitoring.
Following the suspect screening of the UBA list compounds, 78 were purchased for
iden fica on and quan fica on. A er Solid Phase Extrac on (SPE) and LC-HRMS
analysis of the river samples, a total of 9 compounds were confirmed at Level 1 using
reference standards, belonging to different categories of use: 2 benzotriazoles, 1
pharmaceu cal, 1 pes cide, and others from general industrial applica ons. Among
these, 4 compounds showed a 100% detec on frequency across all analysed samples:
chloramine B, benzotriazole, 1H-methylbenzotriazole, and phenazone. These 4
compounds, along with the others, were semi-quan fied, with esmated concentra ons
ranging from 0.04 to 286.04 ng/L.
The results underscore the widespread occurrence and persistence of PMTs across
spa al and ver cal gradients in the river system. This study provides essen al occurrence
data for future regulatory assessments and highlights the value of using priori sed
screening lists combined with advanced analy cal tools to monitor chemical pollu on in
freshwater and estuarine environments.
