Use of microextraction by packed sorbents following selective pressurised liquid extraction for the determination of brominated diphenyl ethers in sewage sludge by gas chromatography-mass spectrometry

Assessing emerging and priority micropollutants in sewage sludge: environmental insights and analytical approaches

The application of sewage sludge (SS) in agriculture, as an alternative to manufactured fertilizers, is current practice worldwide. However, as wastewater is collected from households, industries, and hospitals, the resulting sludge could contaminate land with creeping levels of pharmaceuticals, pesticides, heavy metals, polycyclic aromatic hydrocarbons, and microplastics, among others. Thus, the sustainable management of SS requires the development of selective methods for the identification and quantification of pollutants, preventing ecological and/or health risks. This study presents a thorough evaluation of emerging and priority micropollutants in SS, through the lens of environmental insights, by developing and implementing an integrated analytical approach. A quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction method, coupled with gas chromatography and liquid chromatography, was optimized for the determination of 42 organic compounds. These include organophosphorus pesticides, organochlorine pesticides, pyrethroid pesticides, organophosphate ester flame retardants, polybrominated diphenyl ethers, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons. The optimization of the dispersive-solid phase for clean-up, combined with the optimization of chromatographic parameters, ensured improved sensitivity. Method validation included assessments for recovery, reproducibility, limit of detection (LOD), and limit of quantification (LOQ). Recoveries ranged from 59.5 to 117%, while LODs ranged from 0.00700 to 0.271 µg g-1. Application of the method to seven SS samples from Portuguese wastewater treatment plants revealed the presence of sixteen compounds, including persistent organic pollutants. The quantification of α-endosulfan, an organochlorine pesticide, was consistently observed in all samples, with concentrations ranging from 0.110 to 0.571 µg g-1. Furthermore, the study encompasses the analysis of agronomic parameters, as well as the mineral and metal content in SS samples. The study demonstrates that the levels of heavy metals comply with legal limits. By conducting a comprehensive investigation into the presence of micropollutants in SS, this study contributes to a deeper understanding of the environmental and sustainable implications associated with SS management.

Assessment of benzothiazoles, benzotriazoles and benzenesulfonamides in environmental waters using an optimized combination of microextraction by packed sorbent with programmed temperature vaporization-gas chromatography tandem-mass spectrometry

This work proposes a new method for the quantification of benzothiazoles (BTs), benzotriazoles (BTRs), and benzenesulfonamides (BSAs) in tap water, river water, and wastewater. The protocol involved the use of microextraction by packed sorbent (MEPS), applied for the first time for the extraction of the target analytes, combined with programmed temperature vaporization-gas chromatography-triple quadrupole mass spectrometry (PTV-GC-QqQ-MS). Considering the synergism between MEPS extraction and PTV injection, the experimental variables affecting their performance were simultaneously optimized by "experimental design", while principal component analysis (PCA) was used to find the overall optimal working conditions. Response surface methodology was used to gain a comprehensive understanding of the effects of working variables on method performance. The developed method achieved very good linearities and satisfactory intra- and inter-day accuracies and precisions. The protocol permitted the detection of the target molecules with limit of detection (LODs) values between 0.005 and 0.85 μg/L. The green character of the procedure was evaluated using three metrics: "Analytical Eco-Scale", "Green Analytical Procedure Index" (GAPI), and "Analytical Greenness metric for sample preparation (AGREEprep). The satisfactory results obtained with real water samples demonstrate the applicability of the method for monitoring campaigns and exposome studies.

Green Approaches to Sample Preparation Based on Extraction Techniques

Preparing a sample for analysis is a crucial step of many analytical procedures. The goal of sample preparation is to provide a representative, homogenous sample that is free of interferences and compatible with the intended analytical method. Green approaches to sample preparation require that the consumption of hazardous organic solvents and energy be minimized or even eliminated in the analytical process. While no sample preparation is clearly the most environmentally friendly approach, complete elimination of this step is not always practical. In such cases, the extraction techniques which use low amounts of solvents or no solvents are considered ideal alternatives. This paper presents an overview of green extraction procedures and sample preparation methodologies, briefly introduces their theoretical principles, and describes the recent developments in food, pharmaceutical, environmental and bioanalytical chemistry applications.

Current trends on microextraction by packed sorbent – fundamentals, application fields, innovative improvements and future applications

MEPS, the acronym of microextraction by packed sorbent, is a simple, fast and user- and environmentally-friendly miniaturization of the popular solid-phase extraction technique (SPE).

Comprehensive monitoring of organic micro-pollutants in surface and groundwater in the surrounding of a solid-waste treatment plant of Castellón, Spain

The solid-waste treatment plant of RECIPLASA is located in the municipality of Onda (Castellón province), which is an important agricultural area of Spain, with predominance of citrus crops. In this plant, all urban solid wastes from the town of Castellón (around 200,000 inhabitants) and other smaller towns as Almassora, Benicàssim, Betxí, Borriana, L'Alcora, Onda and Vila-Real are treated. In order to evaluate the potential impact of this plant on the surrounding water, both surface and groundwater, a comprehensive monitoring of organic pollutants has been carried out along 2011, 2012 and 2013. To this aim, an advanced analytical strategy was applied for wide-scope screening, consisting on the complementary use of liquid chromatography (LC) and gas chromatography (GC) coupled to mass spectrometry (MS) with quadrupole (Q)-time of flight analyser (TOF). A generic solid-phase extraction with Oasis HLB cartridges was applied prior to the chromatographic analysis. The screening included more than 1500 organic pollutants as target compounds, such as pesticides, pharmaceuticals, veterinary drugs, drugs of abuse, UV-filters, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), among others. Pesticides, mainly herbicides, were the compounds more frequently detected. Other compounds as antioxidants, cosmetics, drugs of abuse, PAHs, pharmaceuticals and UV filters, were also identified in the screening though at much lower frequency. Once the screening was made, quantitative analysis focused on the compounds more frequently detected was subsequently applied using LC coupled to tandem MS with triple quadrupole analyser. In this way, up to 24 pesticides and transformation products (TPs), 7 pharmaceuticals, one drug of abuse and its metabolite could be quantified at sub-ppb concentrations. Along the three years of study, ten compounds were found at concentrations higher than 0.1μg/L. Most of them were pesticides and TPs, a fact that illustrates that the main source of pollution seems to be the agricultural activities in this area.