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BTEX (Benzene, Toluene, Ethylbenzene, Xylene) 

Why Monitor BTEX?

BTEX occurs naturally in crude oil and produced or used during petroleum refining and by many other industrial processes involving solvents, dyes and paints. In urban areas, particularly with heavy motor vehicle traffic and near petrol stations, BTEX compounds are widely present in the atmosphere. According to World Health Organization (WHO, 2000) Mean ambient air concentrations of benzene in rural and urban areas are about 1 µg/m3 and 5–20 µg/m3, respectively.are


BTEX are increasingly being monitored as a general indication of urban and industrial VOC pollution. To understand better sources and variability of benzene in the atmosphere, it is important to monitor them using a continuous and automated system.


Traditionally, BTEX monitored using passive sampling or sorbent tube. They are analysed using expensive laboratory systems such as GC-MS, which does not offer continuously monitored data and yet are costly and consume more resources to operate. If instead, low-cost total VOC sensors are used, they are not sensitive enough to track and report ambient levels, nor are able to give specific detections of BTEX compounds.are

BTEX Online GC Solution

Chromatotec has developed two solutions for online BTEX monitoring: airmoVOC BTX (GC-FID) and airTOXIC BTX (GC-PID). Both solutions are certified under MCerts to be used in Continuous Ambient Air Quality Monitoring Systems for EN14662-3, EN15267-1, EN15267-2. Chromatotec BTEX analyzers are also tested by US-EPA with the conclusion of overall acceptable results comparing to reference TO-15 method using air sampling canisters and laboratory GC-MS test, while "providing continuous data over 30-minute measurement cycles and significant operational savings”.


Optional internal calibration QC can be built-in with permeation system (A74022) to validate results automatically using certified benzene tube, to ensure repeatability and accuracy.


The airmoVOC BTX analyzer has been developed specifically to address the challenge of online continuous BTEX monitoring. The airmoVOCs perform in the most stringent applications with the lowest cost of ownership in the market. Providing an ideal solution for companies and operators seeking to increase data capture and to maximize efficiency.


AirmoVOC BTEX is perfectly suited for the monitoring of Benzene, Tolulene, Ethylbenzene and Xylenes (optionally, styrene and 1,3-butadiene). It allows the measurement of low and very low BTEX concentrations (down to 10 ppt LDL for benzene). The instrument is robust, compact and very low maintenance and offers excellent result quality repeatability, linearity, stability and sensibility on BTEX compounds. It only requires H2 as a carrier gas through either an external cylinder or an integrated H2 generator.


Chromatec's airTOXIC BTX PID is a GC/PID using a Photo-Ionisation Detector with a self-cleaning 10.6 eV PID lamp for high stability for automatic monitoring of BTEX in air from sub-ppb levels (down to 0.01 ppb LDL for benzene). The best features of the airTOXIC are its sensitivity, compact size, and flexibility. Without the need of H2 gas, airTOXIC is more suited for use in a refinery and petrochemical areas, with Exp CSA or ATEX options. Styrene and cyclohexane can be added to the compound list.

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