L. Vera¹, E. Pagans, R. Domingues, A. Van Harreveld

Parc de Recerca UAB, Edificio EUREKA Espacio P2M2, 08193 Bellaterra. Tel: 935 929 048 Barcelona. ¹ lvera@odournet.com (Luciano Vera)

Keywords: GC-TOFMS, odour, VOC, sensitivity, resolution

Abstract

Knowing the chemical composition of an air sample is a complex challenge because the abundance of substances of different nature and different concentrations. This complexity increases if we want to identify those compounds that cause odors, since many of them are present at very low concentrations, hardly detectable by more conventional instrumental systems. Gas Chromatography (GC) coupled at Mass Spectrometry (MS) GC-MS, is undoubtedly the more robust and consolidated technique in air sample analysis. The more common types of GC-MS are Mass Spectrometers with single quadrupole detector. However, the continuous technological development of analytical instrumentation and especially in Mass Spectrometry allows ever more robust analyses, more sensitive and with improved resolution. In recent years, the interest in GC-TOFMS systems (TOF: time-of-flight) has been increasing, because it involves a faster detector with higher sensitivity and resolution compared to the conventional single quadrupole GC-MS. This paper compares a GCO-TOFMS system recently acquired by Odournet to a more conventional GC-MS quadropolemethod. Both used thermal desorption (TD) for the chemical and sensory analysis of air samples collected in the output of biofilters. The presented results show a clear difference in terms of sensitivity and resolution for GC-TOFMS compared to a conventional GC-MS identifying almost50% more compounds in the same air sample. Additionally an analysis using GCO (GC-sniffing) was performed, showing good complementarity with the results obtained by GC-TOFMS for the same sample.

R. López¹, I. Cabeza¹, J. R. Lock-Wah-Hoon¹, I. Giráldez ², M. Ruíz³, M. J. Díaz³

¹ Instituto de Recursos Naturales y Agrobiología de Sevilla-CSIC, Avda. Reina Mercedes 10, 41012 Sevilla. rlnunez@irnase.csic.es.

² Departamento de Química y Ciencia de los Materiales, Facultad de Ciencias Experimentales, Univ. de Huelva, Campus Universitario El Carmen, Avenida de las Fuerzas Armadas, 21071-Huelva.

³ Departamento de Ingeniería Química, Química Física y Química Orgánica, Facultad de Ciencias Experimentales, Univ. de Huelva, Campus Universitario El Carmen, Avenida de las Fuerzas Armadas, 21071-Huelva.

Keywords: Volatile organic compounds, terpenoid

Abstract

The volatile organic compound (VOC) α-pinene, one of the most abundant component emitted during the composting of urban waste (MSW) and pruning waste (P), was treated in biofilters filled up with a MSW compost or a MSW+P compost. A photoionization detector was used to carry out the monitoring of the biofilters efficiency but GC-MS and an electronic nose were also used for the process study. Moisture content in biofilters below 66% (dw, MSW) or 51% (dw, MSWP) made efficiency decrease to less than 90%. GC-MS spectra indicated no intermediate products from α-pinene degradation appeared but e-nose data indicates a “smell” corresponding to S-compounds produced in MSW biofilter. These results show that electronic noses could become a powerful tool for the monitoring of VOC compounds in biofiltering and composting processes.