Oil Spill Source Identification Using Colorimetric Detection

Abstract

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, but also 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.