Evaluation of Novel Sorptive Extraction Techniques
- Autores: Sameer Shamrao Lakade
- Directores de la Tesis: Núria Fontanals (dir. tes.)
- Lectura: En la Universitat Rovira i Virgili ( España ) en 2017
- Idioma: español
- Tribunal Calificador de la Tesis: Victòria Salvadó Martín (presid.), Eva Pocurull Aixalà (secret.), Lourdes Ramos Rivero (voc.)
- Materias:
- Enlaces
- Tesis en acceso abierto en: hdl.handle.net
- Resumen
In recent years, one of the environmental concern is the presence of the different types of emerging organic contaminants (EOCs) in the different compartments of environment; being water one of the most affected. This is because of the modern industrialization, urbanization and modern lifestyles which have caused many significant changes in the environment that in turn affect aquatic and territorial wildlife, as well as human health.
To evaluate the occurrence, the distribution and the adverse effects on the environment, efficient and reliable analytical methods are needed. The presence of EOCs at low concentrations levels, their high solubility, and their interaction with complex environmental matrices make their determination more challenging. The best choice for the determination of these contaminants in environmental waters is liquid chromatography (LC) coupled to tandem mass spectrometry (MS/MS) based detector.
However, due to the low concentration of these contaminants in environmental samples, a sample preparation technique is needed for their extraction from the samples. The most commonly employed sorptive extraction techniques are solid-phase extraction (SPE), solid-phase microextraction (SPME), and stir bar sorptive extraction (SEBS), among others, although new extraction techniques are emerging. Therefore, the objective of the Doctoral Thesis is the evaluation and application of the novel sorptive extraction techniques for the extraction of EOCs from environmental water samples.
In detail, this Doctoral Thesis is mainly focused on the recently introduced novel extraction techniques such as fabric phase sorptive extraction (FPSE), dynamic FPSE (DFPSE), capsule phase microextraction (CPME) and dispersive solid-phase extraction (d-SPE) using a novel hypercrosslinked magnetic particles, which were evaluated for the extraction of different contaminants such as pharmaceutical and personal care products (PPCPs) and sweeteners (SWs) which acted as model compounds. All these extraction techniques are followed by LC-MS/MS for the determination of these contaminants in environmental samples.
The first section is dedicated to the FPSE technique, which is based on the principle of equilibrium extraction. The technique was developed to readdress the limitation of SPME and SBSE techniques. In this technique, a porous surface of cellulose or polyester fabric material is used as a substrate, which is uniformly coated with different materials through sol-gel technology. This fabric material in equilibrium mode was evaluated for the extraction of a group of PPCPs that covers a wide range of polarity. Four different types of FPSE coatings were evaluated and compared. The best one as well as the optimal parameters of the extraction were selected for the method development, that was based on FPSE followed by LC-MS/MS, and the results obtained from that were comparable with previously studied SBSE technique.
In the same section, a new design of FPSE technique was developed that is known as DFPSE and applied for the extraction of the same group of the PPCPs in environmental water samples. The DFPSE consists of the 47 mm round fabric flexible disk, which overcomes the limitation of long equilibrium extraction time of static FPSE. In DFPSE mode, the sample is percolated through the fabric sorbent material using a filtration assembly. Then, the retained analytes were eluted by passing the solvent through the same assembly. In this study, different parameters affecting the extraction were optimized for the sorbent material in order to increase extraction recovery of the analytes and results were compared with static FPSE and other sample preparation techniques. The optimal method was validated and applied to determine these PPCPs from different environmental waters such as surface and sewage water samples.
In the second section, a recently introduced sample preparation technique known as CPME was evaluated for the first time for the extraction of personal care products (PCPs). In CPME the extraction is carried out with a microextraction capsule (MEC). It consists of two sealed porous membranes, one of them encapsulated with different polymer/functional moieties and coated by sol-gel technology; the other one, hosts a magnetic rod which allows spinning the device when it is placed on a magnetic stirrer. The optimal developed method was validated and applied to analyse similar environmental water samples.
The last section describes the evaluation of novel hypercrosslinked magnetic particles Q-100 under d-SPE mode. The new sorptive material has the advantages of hypercrosslinked structure, high surface area, and suitable pore size distribution. In viewing those features, the MPs was evaluated towards the retention of a group of SWs, which includes very polar compounds. The different parameters affecting the extraction were firstly optimized. Next, the optimized d-SPE method was validated and applied to analyze different environmental samples.
