Oil spill source identification using colorimetric detection

The colorimetric detection of polycyclic aromatic hydrocarbons (PAHs) was investigated for the quick and easy identification of likely oil spill offenders. In this new technology, photochromic compounds were used to sense PAHs by varying their photoswitching capacity. To that end, three photochromes were designed and showed varying degrees of photoswitching inhibition depending on PAH analyte, photochrome and excitation wavelength. PAH mixtures that mimic oil spills showed the same varying response and demonstrated the accuracy of this technology. To prove the applicability of this technology, an array was assembled using the three photochromes at three excitation wavelengths and tested against authentic crude oil samples. Not only could these samples be differentiated, weathering of two distinctly different oil samples showed limited variation in response, demonstrating that this may be a viable technique for in situ oil identification

A colorimetric approach towards polycyclic aromatic hydrocarbon sensing

The colorimetric detection of polycyclic aromatic hydrocarbons (PAHs) was achieved using photochromic compounds. This technique exploits the ability of the photochromic compound to reversibly change from a colourless to a coloured compound using ultraviolet light and visible light. In the presence of a PAH, this photoisomerization is inhibited. The degree of inhibition corresponded to the molar absorptivity and excitation wavelength of the PAH, and with a limit of detection in the micromolar range, the current method delivers a highly sensitive and selective technology. In addition, PAH mixtures were successfully identified using this method, providing a potentially fast in-field sensing technology for the identification of likely sources of spilled oil