Quantifying organic
micropollutants (OMPs) in aquatic
environments
and assessing their removal by water treatment requires expensive
and time-consuming analyses typically using liquid chromatographic
separation and tandem mass spectrometry (LC-MS/MS). In this study,
we evaluated the potential for detecting fluorescent OMPs via spectroscopy,
which is cheap, rapid, and widely accessible. The method involved
using a priori PARAFAC models to eliminate interfering background
fluorescence emitted by naturally occurring dissolved organic matter.
Of 20 screened pharmaceutical OMPs, three (ciprofloxacin, naproxen,
and zolpidem) with calculated fluorescence quantum yields 0.14, 0.21,
and 0.71, respectively, could be quantified in the low μg L–1 range when added alone or in combination to water
samples without any sample pretreatment other than filtration and
pH adjustment. Limits of detection for all three OMPs were 1.0–3.3
μg L–1 in surface waters, while in wastewater,
they were 0.6–9.0 μg L–1 for ciprofloxacin
and naproxen and 1.0–2.6 μg L–1 for
zolpidem. Given the high cost of pharmaceutical analyses and widespread
availability of fluorometers, the new approach will improve access
to rapid and cost-effective results by supporting data-intensive lab-scale
studies, wherein the types of OMPs studied and their concentration
ranges are under the control of the analyst.