Fluorescence Excitation-Emission Spectroscopy: An Analytical Technique to Monitor Drugs of Addiction in Wastewater

Abstract

Emerging contaminants of concern have become a serious issue for the scientific community and society more broadly in recent years due to their increasingly widespread environmental distribution and largely unknown environmental and human health impacts. This study aimed to explore the use of fluorescence excitation-emission (F-EEM) spectroscopy as an alternative analytical method to evaluate the presence of key drugs of addiction (benzoylecgonine, methamphetamine, MDMA, codeine and morphine) in wastewater treatment plants. The chemicals of interest from wastewater were extracted by mixed-mode solid phase extraction and quantified using liquid chromatography tandem mass spectrometry. The same wastewater samples were also analysed by a fluorescence spectrophotometer for fluorescence spectra at wavelengths 280–600 nm (emission) and 200–600 nm (excitation). The study also investigated the relevance of different methods for interpreting F-EEM matrices data including parallel factor analysis (PARAFAC) modelling and fluorescence regional integration technique. PARAFAC identified four components, and among them, component C2, identified at the λex/λem = 275/340 nm wavelength associated with proteinaceous compounds most likely related to tryptophan amino acid, showed significant correlation with codeine removal. MDMA and morphine were not correlated to any of the fluorescence regions. The fluorescence regions related to aromatic protein-like fluorescence were correlated significantly with drug concentration and so may offer a suitable alternative approach for monitoring drugs including benzoylecgonine, methamphetamine and codeine.

Chemical Transformation of Humic Acid Molecules under the Influence of Mineral, Fungal and Bacterial Fertilization in the Context of the Agricultural Use of Degraded Soils

“…Another interesting phenomenon was a local (not occurring at all dates) increase in FI in the region of ~300 nm/450 nm (ex/em). These changes could reflect newly formed, low-molecular HAs, which may have resulted from the activity of microorganisms [ 68 , 69 ]. The spectral location of this maximum can also be attributed to molecules more similar to fulvic acids [ 70 ].…”

Multidimensional fluorescence spectroscopy of wine using synchronous excitation/emission matrices and time-resolved fluorescence interferometric detection

“…Three-dimensional fluorescence excitation-emission matrices (EEM) measure the intensity of the light emitted by a sample over the entire range of scanned excitation and emission wavelengths. EEM analysis has been increasingly adopted in fields including drugs in wastewater [11], oil pollutants [12,13] and foods [8][9][10]14], to name just a few. Previous studies have shown the possibility of using steady-state multidimensional fluorescence spectroscopy in studies of various wines [15][16][17][18][19], brandies and wine distillates [20] and other beverages including beer [21].…”

Insightful Analysis and Prediction of SCOD Component Variation in Low-Carbon/Nitrogen-Ratio Domestic Wastewater via Machine Learning

“…The results indicated that COD concentration was positively correlated with humic-like substances. Several studies [20,21] have sought to investigate the potential of fluorescence excitation-emission (F-EEM) spectroscopy as an alternative analytical method for assessing the relationship between the presence of crucial drugs of addiction, ammonia, and pH with PARAFAC components. However, the correlation analysis techniques used in the above studies were RDA, canonical correlation, or linear correlation analysis methods.…”