Sub-ppb level detection of BTEX gaseous mixtures with a compact prototype GC equipped with a preconcentration unit

Irene Lara-Ibeas (1, 2) , Alberto Rodríguez-Cuevas , Christina Andrikopoulou (1) , Vincent Person , Lucien Baldas (2) , Stéphane Colin (2) , Stéphane Le Calvé (1)

1 ICPEES - Institut de chimie et procédés pour l'énergie, l'environnement et la santé
2 ICA - Institut Clément Ader

In this work, a compact gas chromatograph prototype for near real-time benzene, toluene, ethylbenzene and xylenes (BTEX) detection at sub-ppb levels has been developed. The system is composed of an aluminium preconcentrator (PC) filled with Basolite C300, a 20 m long Rxi-624 capillary column and a photoionization detector. The performance of the device has been evaluated in terms of adsorption capacity, linearity and sensitivity. Initially, PC breakthrough time for an equimolar 1 ppm BTEX mixture has been determined showing a remarkable capacity of the adsorbent to quantitatively trap BTEX even at high concentrations. Then, a highly linear relationship between sample volume and peak area has been obtained for all compounds by injecting 100-ppb samples with volumes ranging from 5-80 mL. Linear plots were also observed when calibration was conducted in the range 0-100 ppb using a 20 mL sampling volume implying a total analysis time of 19 min. Corresponding detection limits of 0.20, 0.26, 0.49, 0.80 and 1.70 ppb have been determined for benzene, toluene, ethylbenzene, m/p-xylenes and o-xylene, respectively. These experimental results highlight the potential applications of our device to monitor indoor or outdoor air quality.

Mots clés: BTEX; microfluidics; PID detector; miniaturized gas chromatograph; preconcentrator

Domaines: Chimie; Chimie analytique; Sciences de l'environnement; Océan, Atmosphère

Irene Lara-Ibeas, Alberto Rodríguez-Cuevas, Christina Andrikopoulou, Vincent Person, Lucien Baldas, et al.. Sub-ppb level detection of BTEX gaseous mixtures with a compact prototype GC equipped with a preconcentration unit. Micromachines, 2019, 10 (3), pp.187. ⟨10.3390/mi10030187⟩. ⟨hal-02067043v2⟩