Novel analytical methodologies for the analysis of organic micropollutants in environmental samples

• Autores: Miren Pena Abaurrea
• Directores de la Tesis: Lourdes Ramos Rivero (dir. tes.), María del Carmen Quintana Mani (tut. tes.)
• Lectura: En la Universidad Autónoma de Madrid ( España ) en 2012
• Idioma: español
• Tribunal Calificador de la Tesis: Jesús Sanz Perucha (presid.), Jesús Rodríguez Procopio (secret.), Begoña Jiménez Luque (voc.), Pilar Fernández Hernando (voc.), Jean-François Focant (voc.)
• Materias:
  • Química
    • Química analítica
      • Análisis cromatográfico
• Enlaces
  • Tesis en acceso abierto en: digitool-uam.greendata.es
• Resumen

  • The present PhD work focuses in the development of new analytical procedures for the analysis of trace organic pollutants in relevant environmental samples. Studies have focused in two aspects: the development and validation of novel miniaturised, simplified/generic, and green sample preparation procedures, and the evaluation of the feasibility of comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC¿ToF MS) to solve specially difficult coelution problems that can hardly be solved using monodimensional GC-based techniques, and to develop multiresidual and non-target analysis in complex extracts.

    The first section of this PhD book is an Introduction chapter (Section 1). The first part of this chapter summarizes the physicochemical properties, origin, environmental fate, toxicity and, when available, current legislative situation of the several analytes considered in the study. Then, an overview of both conventional and miniaturised sample preparation methods in use for the determination of the test analytes in complex (solid and semi-solid) biotic and abiotic matrices is presented. The main practical advantages and limitations of both types of analytical approaches as well as their relative merits for routine analysis are deeply discussed. At the end of this section, a review on miniaturization in analytical chemistry, corresponding to a chapter included in the book entitle ¿Challenges in Green Analytical Chemistry¿, is included. The main instrumental requirements demanded for this type of determination have been summarized in the last part of this section, and a book chapter reviewing relevant environmental application studies involving GC×GC is also presented.

    The main and specific objectives of the present work are summarised in the second section of the book (Section 2). Objectives have been set on the base of present state of knowledge in the fields of sample preparation and of GC×GC¿ToF MS for the analysis of organohalogenated compounds and microcontaminants in complex (semi-)solid environmental samples.

    The most relevant results concerning the development of miniaturised, simplified and generic sample preparation methods for the determination of the investigated trace compounds are presented in the third part of the book. Section 3.1.1 reports on the use of hot Soxhlet for the determination of different organobromines (including PBDEs, MeO-PBDEs, TBA, MHC-1 and PBHDs) in tuna muscles from the Mediterranean sea. In the next two sections (Sections 3.1.2 and 3.1.3) the combined use of matrix solid-phase dispersion (MSPD) and pressurised liquid extraction (PLE) with in-cell packing of the clean-up sorbents is proposed as an efficient analytical strategy for exhaustive extraction and simultaneous purification of the studied microcontaminants. The feasibility of the approach has been demonstrated for the simultaneous analysis of PCBs and PBDEs in feedstuffs (Section 3.1.2) and of PCBs in sediments (Section 3.1.3). Finally, in Section 3.1.4, the use of ultrasonic-probe assisted extraction (UAE) in combination with solid phase extraction in disposable pipette tip is proposed for the fast and cost-effective extraction and purification of PCBs in small-size (semi-)solid samples (i.e., 50 mg of sample).

    The second section of the third chapter of this book (Section 3.2) evaluates the feasibility of GC×GC¿ToF MS for the chromatographic separation of specific pairs/groups of analytes that are difficult to determine accurately by monodimensional GC-based approaches, the simultaneous analysis of different families of pollutants, and the screening and tentative identification of analytes from which previous information is not available (non-target analysis). Thereby, in Section 3.2.1 the potential of GC×GC¿ToF MS for the simultaneous determination of several families of organobromines, including PBDEs, MeO-PBDEs, PBHDs, diMeO-PBDEs and other emerging analytes, in tuna muscles has been investigated. Moreover, considering both the typical structured chromatograms obtained with GC×GC and the MS structural information provided by ToF MS, a tentative identification of additional non-target organobromines was also achieved. Interestingly, some novel PBHD isomers, not previously described in the literature could be also identified. Section 3.2.2 describes a GC×GC¿ToF MS-based methodology for the analysis of the 15+1 EU PAHs in sediments from a protected area in the South of Spain, The Cadiz Bay. The enhanced identification power provided by the use of GC×GC¿ToF MS allowed the complete separation of critical co-eluting PAH pairs/groups which had not been previously resolved when using monodimensional GC-based techniques.

    Finally, the main conclusions of the most relevant results achieved in the present study are summarised in Section 4.