http://hdl.handle.net/2117/5680 Wed, 19 Jun 2013 15:05:37 GMT 2013-06-19T15:05:37Z webmaster.bupc@upc.edu Universitat Politècnica de Catalunya. Servei de Biblioteques i Documentació no http://hdl.handle.net/2117/10153 Title: Comparative of the adsorption performance of a multi-sorbent bed Authors: Gallego Piñol, Eva; Roca Mussons, Francisco Javier; Perales Lorente, José Francisco; Guardino, Xavier Abstract: Ambient air is a very complex mixture of compounds, and has a very variable composition and concentration of pollutants. Hence, a good choice of sorbent or a good combination of different sorbents may allow the determination of a wide range of target compounds in air samples, as well as achieve high breakthrough volumes. The selective characteristics of the sorbent chosen would determine the removing of the target compounds from the air matrix. On the other hand, a choice of a proper sorbent for the range of the studied target compounds would eliminate problems derived from breakthrough values. The capacity of a sorbent to retain specific compounds is usually evaluated by measuring the breakthrough volume of a concrete compound on the sorbent. To maximize sampling efficiency, the maximum volume of air that can be sampled without loss of adsorbent must be known. Tenax TA has been determined to be a not suitable adsorbent for very volatile organic compounds (VVOCs, 0<boiling point<50-100ºC (WHO, 1989)). However, Tenax TA continues being one of the most widely used adsorbents for the preconcentration of VOCs. In addition to that, generally, a single adsorbent cannot be appropriate for the majority of compounds present in ambient air. Hence, a combination of several adsorbents may result in better performances. Two types of adsorbent tubes, one containing a mixture of three adsorbents (Carbotrap, Carbopack X, Carboxen 569) and another containing Tenax TA were compared to evaluate their usefulness as active adsorbents of ambient air VOCs, including VVOCs. Fri, 05 Nov 2010 16:58:15 GMT http://hdl.handle.net/2117/10153 2010-11-05T16:58:15Z Gallego Piñol, Eva; Roca Mussons, Francisco Javier; Perales Lorente, José Francisco; Guardino, Xavier no Ambient air is a very complex mixture of compounds, and has a very variable composition and concentration of pollutants. Hence, a good choice of sorbent or a good combination of different sorbents may allow the determination of a wide range of target compounds in air samples, as well as achieve high breakthrough volumes. The selective characteristics of the sorbent chosen would determine the removing of the target compounds from the air matrix. On the other hand, a choice of a proper sorbent for the range of the studied target compounds would eliminate problems derived from breakthrough values. The capacity of a sorbent to retain specific compounds is usually evaluated by measuring the breakthrough volume of a concrete compound on the sorbent. To maximize sampling efficiency, the maximum volume of air that can be sampled without loss of adsorbent must be known. Tenax TA has been determined to be a not suitable adsorbent for very volatile organic compounds (VVOCs, 0<boiling point<50-100ºC (WHO, 1989)). However, Tenax TA continues being one of the most widely used adsorbents for the preconcentration of VOCs. In addition to that, generally, a single adsorbent cannot be appropriate for the majority of compounds present in ambient air. Hence, a combination of several adsorbents may result in better performances. Two types of adsorbent tubes, one containing a mixture of three adsorbents (Carbotrap, Carbopack X, Carboxen 569) and another containing Tenax TA were compared to evaluate their usefulness as active adsorbents of ambient air VOCs, including VVOCs. http://hdl.handle.net/2117/10106 Title: Evaluation of Radiello diffusive sampler indicated for thermal desorption for measuring VOCs in ambient air. Authors: Gallego Piñol, Eva; Roca Mussons, Francisco Javier; Perales Lorente, José Francisco; Guardino, Xavier Abstract: - One of the key aspects regarding air monitoring is to determine the suitability of the methodology chosen. -The comparison between validated active air multi-sorbent tubes and Radiello diffusive samplers show no significant differences between the two methodologies for several compounds studied. -For the Radiello passive sampler, relevant differences have not been observed between the sum of two shorter sampling periods (4 days + 3 days) and a longer sampling period (7 days). -The Radiello diffusive sampler provides satisfactory quantitative measurements and is suitable for the determination of several VOCs in ambient air. -Radiello passive sampler coupled with ATD-GC/MS is a simple to use, sensible and cheap method to assess ambient air concentrations of VOCs. -More research has to be done to enhance the results obtained in this study. Thu, 04 Nov 2010 11:48:11 GMT http://hdl.handle.net/2117/10106 2010-11-04T11:48:11Z Gallego Piñol, Eva; Roca Mussons, Francisco Javier; Perales Lorente, José Francisco; Guardino, Xavier no - One of the key aspects regarding air monitoring is to determine the suitability of the methodology chosen. -The comparison between validated active air multi-sorbent tubes and Radiello diffusive samplers show no significant differences between the two methodologies for several compounds studied. -For the Radiello passive sampler, relevant differences have not been observed between the sum of two shorter sampling periods (4 days + 3 days) and a longer sampling period (7 days). -The Radiello diffusive sampler provides satisfactory quantitative measurements and is suitable for the determination of several VOCs in ambient air. -Radiello passive sampler coupled with ATD-GC/MS is a simple to use, sensible and cheap method to assess ambient air concentrations of VOCs. -More research has to be done to enhance the results obtained in this study.