León Morán, Lixy Olinda

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León Morán, Lixy Olinda

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Open Access
Monitoring of hydroxylated polycyclic aromatic hydrocarbons in human tissues: targeted and untargeted approaches using liquid chromatography‐high resolution mass spectrometry
(Wiley-VCH Verlag , 2023-07-04) León Morán, Lixy Olinda; Pastor Belda, Marta; Campillo Seva, Natalia; Arroyo Manzanares, Natalia; Torres Sánchez, Carmen; Viñas López-Pelegrin, Pilar; Química Analítica; Facultades de la UMU::Facultad de Química
Hydroxylated polycyclic aromatic hydrocarbons are metabolites of persistent organic pollutants which are formed during the bioactivation process of biological matrices and whose toxicity is being studied. The aim of this work was the development of a novel analytical method for the determination of these metabolites in human tissues, known to have bioaccumulated their parent compounds. Samples were treated by salting‐out assisted liquid‐liquid extraction and the extracts were analyzed by ultra‐high performance liquid chromatography coupled to mass spectrometry with a hybrid quadrupole‐time‐of‐flight analyzer. The proposed method achieved limits of detection in the 0.15–9.0 ng/g range for the five target analytes (1‐hydroxynaphthalene, 1‐hydroxypyrene, 2‐hydroxynaphthalene, 7‐hydroxybenzo[a]pyrene, and 9‐hydroxyphenanthrene). The quantification was achieved by matrix‐matched calibration using 2,2´‐biphenol as internal standard. For all compounds, relative standard deviation, calculated for six successive analyses, was below 12.1%, demonstrating good precision for the developed method. None of the target compounds was detected in the 34 studied samples. Moreover, an untargeted approach was applied to study the presence of other metabolites in the samples, as well as their conjugated forms and related compounds. For this objective, a homemade mass spectrometry database covering 81 compounds was created and none of them was detected in the samples.
Open Access
Monitorization of ibuprofen, diclofenac and triclosan and their photolytic transformation products
(Elsevier, 2025-06-03) León Morán, Lixy Olinda; Pastor Belda, Marta; Campillo Seva, Natalia; Arroyo Manzanares, Natalia; Viñas López-Pelegrin, Pilar; Martínez-Escudero, Carmen Maria; Garrido, Isabel; Contreras, Fulgencio; Hellín, Pilar; Flores, Pilar; Aliste, Marina; Fenoll, José; Química Analítica; Facultades de la UMU::Facultad de Química
The presence of contaminants of emerging concern (CECs) in wastewater treatment plant (WWTP) effluents poses a significant risk to human health and the environment. The application of photolytic processes in remediation of WWTP effluents results in the formation of transformation products (TPs) with unknown environmental impact. Thus, the identification of TPs and the monitoring of their evolution during the remediation process is of great interest. This study presents a new analytical method for the determination of three CECs (ibuprofen, IBU; diclofenac, DCF; triclosan, TCS) and their respective TPs in water subjected to direct photolysis by ultraviolet A irradiation with light emitting diode lamps. The analytes were extracted using in situ ionic liquid dispersive liquid–liquid microextraction and analysed by liquid chromatography with high resolution mass spectrometry (LC-HRMS) for the identification of known and unknown TPs. The identification of TPs was conducted through two untargeted strategies: a suspect screening based on the utilization of a home-made database created from the TPs previously described, and a screening for novel TPs based on the spectral investigation of a deconvoluted and aligned list of peaks with suitable degradation trends. The proposed analytical strategy allowed up to 39 TPs being identified, with 10 of them being structurally proposed for the first time in this study. In addition, verification of the identified TPs was carried out by LC with triple quadrupole. Moreover, the three CECs and their TPs were monitored in four WWTP samples subjected to degradation trials and two TPs (DCF-TP296C and TCS-TP303C) were found.
Open Access
Discrimination of Diptera order insects based on their saturated cuticular hydrocarbon content using a new microextraction procedure and chromatographic analysis
(Royal Society of Chemistry, 2024-04-15) León Morán, Lixy Olinda; Pastor Belda, Marta; Viñas López-Pelegrin, Pilar; Arroyo Manzanares, Natalia; García García, María Dolores; Arnaldos Sanabria, María Isabel; Campillo Seva, Natalia; Zoología y Antropología Física
The nature and proportions of hydrocarbons in the cuticle of insects are characteristic of the species and age. Chemical analysis of cuticular hydrocarbons allows species discrimination, which is of great interest in the forensic field, where insects play a crucial role in estimating the minimum post-mortem interval. The objective of this work was the differentiation of Diptera order insects through their saturated cuticular hydrocarbon compositions (SCHCs). For this, specimens fixed in 70 : 30 ethanol : water, as recommended by the European Association for Forensic Entomology, were submitted to solid–liquid extraction followed by dispersive liquid–liquid microextraction, providing preconcentration factors up to 76 for the SCHCs. The final organic extract was analysed by gas chromatography coupled with flame ionization detection (GC-FID), and GC coupled with mass spectrometry was applied to confirm the identity of the SCHCs. The analysed samples contained linear alkanes with the number of carbon atoms in the C9–C15 and C18–C36 ranges with concentrations between 0.1 and 125 ng g−1 . Chrysomya albiceps (in its larval stage) showed the highest number of analytes detected, with 21 compounds, while Lucilia sericata and Calliphora vicina the lowest, with only 3 alkanes. Non-supervised principal component analysis and supervised orthogonal partial least squares discriminant analysis were performed and an optimal model to differentiate specimens according to their species was obtained. In addition, statistically significant differences were observed in the concentrations of certain SCHCs within the same species depending on the stage of development or the growth pattern of the insect.
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Photocatalytic oxidation of carbamazepine in water using TiO2 with LED lamps: Study of intermediate degradation products by liquid chromatography mass spectrometry after dispersive liquid–liquid microextraction
(Elsevier, 2024-07-01) Martínez Escudero, Carmen Maria; Garrido, Isabel; Contreras, Fulgencio; Hellín Pilar; Flores Pilar; Arroyo Manzanares, Natalia; Viñas López-Pelegrin, Pilar; Campillo Seva, Natalia; Fenoll, José; León Morán, Lixy Olinda; Química Analítica
An evaluation of carbamazepine (CBZ) photolysis degradation in water under different experimental conditions is here presented for wastewater detoxification. For this, an analytical methodology based on a green sample treatment procedure and liquid chromatography with mass spectrometry (LC-MS) using both quadrupole time-of-flight (QTOF) and triple quadrupole (QqQ) analyzers has been proposed. Dispersive liquid–liquid microextraction (DLLME) provides high preconcentration efficiency for the pharmaceutical emerging contaminant, allowing its monitorization and that of its transformation products (TPs) with high sensitivity. Subsequently, the established analytical method has been applied to study of behaviour of CBZ and its TPs generated in water during photolysis treatments in the presence and the absence of the catalyst TiO2 Degussa P25 and irradiating with ultraviolet (UV) and visible (Vis) light emitting diode (LED) lamps as light source. Nineteen TPs were tentatively identified. A significantly higher degradation rate of CBZ and its TPs was observed with the use of UV-LED lamps during the heterogeneous photocatalysis based treatment.
Open Access
Targeted and untargeted approaches using liquid chromatography with high-resolution mass spectrometry for the determination of lipophilic marine biotoxins in seawater and mussel samples
(Elsevier, 2025-09-12) Pastor Belda, Marta; Arroyo Manzanares, Natalia; Viñas López-Pelegrin, Pilar; Sánchez Fernández, Olga; Pérez Ruzafa, Ángel; Campillo Seva, Natalia; León Morán, Lixy Olinda; Química Analítica
Marine biotoxins are naturally occurring compounds produced around the world by various species of microalgae, whose presence increases significantly due to harmful algal blooms. This phenomenon is a major public health concern, as a large amount of marine fauna is exposed to these biotoxins. The aim of this study was the improvement and application of dispersive liquid-liquid microextraction and liquid chromatography coupled to high-resolution mass spectrometry for the determination of eight lipophilic marine biotoxins, okadaic acid (OA), dinophysistoxin 1 (DTX-1), dinophysistoxin 2 (DTX-2), 16:0 7-O-acyl okadaic acid (DTX-3a), gambierone (GAM), 44-methylgambierone (44-GAM), yessotoxin (YTX), and homoyessotoxin (hYTX), and their derivatives in seawaters and mussels by targeted and untargeted approaches. The proposed method provided detection limits ranging from 0.0004 to 1.7 ng mL-1 in seawater and 0.06 to 119 ng g-1 in mussel samples, depending on the biotoxin. A total of 23 seawater samples collected in the Mar Menor lagoon between 2021 and 2023 were analyzed and several of them were found to contain OA and DTX-3a at concentration levels in the 0.006–1.5 ng mL-1 range. OA and DTX-2 were also found at maximum levels of 8.0 and 1.2 ng g-1, respectively, in several mussel samples from commercial origin. In addition, a suspect screening was developed in the untargeted approach to investigate the presence of other derivatives of the target marine biotoxins in the samples using a home-made database covering 93 compounds. An unsaturated ester derivative of OA/DTX-2 was detected in the seawater samples collected during a red tide.
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Photodecomposition of antibiotics and their transformation products in wastewaters using ZnO and TiO2 with LED lamps
(Elsevier, 2024-09-01) Martínez Escudero, Carmen Maria; Garrido, Isabel; Contreras, Fulgencio; Hellín, Pilar; Flores, Pilar; Arroyo Manzanares, Natalia; Campillo Seva, Natalia; Pastor Belda, Marta; Viñas López-Pelegrin, Pilar; Fenoll, José; León Morán, Lixy Olinda; Química Analítica
This work presents a study of the behavior of three antibiotics (erythromycin (ERY), clarithromycin (CLR) and sulfadiazine (SFZ)) and their transformation products (TPs), generated after photolytic and photocatalytic (TiO2 and ZnO) treatments, in wastewater irradiated with ultraviolet (UV) light emitting diode (LED) lamps as light source. For this, an analytical methodology for the antibiotics and their TPs was developed. Thus, samples were treated by salting-out assisted liquid–liquid extraction (SALLE) and identification and quantification was carried out by liquid chromatography with mass spectrometry (LC-MS) using quadrupole time-of-flight (QTOF) and triple quadrupole (QqQ) analyzers, respectively. The results revealed the presence of 14, 13 and 5 TPs of ERY, CLR and SFZ, respectively, being found in wastewaters spiked with the antibiotics during photo-oxidation treatment. Subsequently, the established analytical method was also applied, in a real case, to study of behavior of these pharmaceuticals (0.2 mg L-1) and their TPs generated in wastewater during a photocatalytic treatment. In this case, 13, 11 and 2 TPs were tentatively identified ERY, CLR and SFZ, respectively. In addition, the photocatalytic treatment using TiO2 exhibited higher degradation rate than photocatalytic treatment using ZnO. The ECOSAR programme was used to estimate the potential ecotoxicity of the identified TPs. The results showed a potential hazard of SFZ, CLR, ERY and some of their TPs to aquatic organisms. Furthermore, some of the identified TPs were found to be more toxic than their parent compounds.
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Degradation of imidacloprid in water by photo-Fenton process using UV-LED lamps at neutral pH: Study of intermediate products by liquid chromatography mass spectrometry after dispersive liquid–liquid microextraction
(Elsevier, 2024-03-01) Martínez Escudero, Carmen Maria; Garrido, Isabel; Contreras, Fulgencio; Hellín, Pilar; Flores, Pilar; Arroyo Manzanares, Natalia; Campillo Seva, Natalia; Pastor Belda, Marta; Viñas López-Pelegrin, Pilar; Fenoll, José; León Morán, Lixy Olinda; Química Analítica
In the present study, a suitable analytical method to determine imidacloprid (IMI) and its main transformation products (TPs) in water by means of dispersive liquid–liquid microextraction (DLLME) combined with liquid chromatography coupled to mass spectrometry (LC-MS), using both quadrupole-time-of-flight (QTOF) and triple quadrupole (QqQ) analysers, has been developed. In addition, the structures of major products formed when IMI is photo-oxidized using ultraviolet A (UVA) irradiation with light emitting diode (LED) lamps were established. Finally, the behaviour of IMI and its main TPs generated in water during photo-Fenton processes at neutral pH using two ferric iron complexes, with ethylenediamine-N,N-disuccinic acid (EDDS) and nitrilotriacetic acid (NTA) as chelating agents, was studied. DLLME was found to efficiently preconcentrate IMI and IMI TPs from the water matrix using chloroform (as extractant solvent) and acetonitrile (as dispersant solvent) in a simple step. The selectivity of the used techniques provided unequivocal identification of IMI and its TPs and their quantification with high sensitivity during the photo-Fenton treatments. In addition, the photo-Fenton treatment using EDDS exhibited higher degradation rate than photo-Fenton treatment using NTA.