Many online VOC detectors do not measure VOC content in water accurately due to the large diversity in properties of these compounds. Methods relying on stripping and then measuring VOCs in gas phase alone is inaccurate (e.g. gas stripping and membrane pervaporation) as many VOC molecules have some polarity and hence affinity to water. This unique approach measures VOCs in water directly using high temperature catalysis (similar to Total Organic Compounds analysis) after excluding longer chain carbon molecules via a specially configured polymer membrane setup. When complimented with gas sparging, this method detects the full range of VOCs present in water in contrast to the partial measurement offered by other methods.
The innovative technology comprises of a process to capture a wide range of VOCs using both sparging and membrane filtration which is oxidized directly by high temperature catalysis to produce carbon dioxide. The CO2 will be quantified by a non-dispersive infrared detector.
Employing a dual approach, VOCs in water are first stripped from water using an inert gas. Then the water sample which may still contain many types of VOCs which are miscible or semi-miscible in water (therefore making it hard to be stripped into gas phase) is passed through a polymer membrane. This membrane is configured to separate these VOCs from longer chain organic compounds. The VOCs from both channels are then converted to CO2 via high temperature catalysis and measured with an IR detector.
The technology has the following features: