A Compact and Sensitive Metal-Capillary Fluorometer: Application to Online Monitoring Oil Spill

Due to the frequent occurrence of marine oil spill accidents and related ecological pollution, online detection of oil-slick thickness is important. Fluorescence detection of oil slick has the advantages of high sensitivity and no need of reagent. Herein, a compact and sensitive fluorometer consisted of two metal capillary (MC), a UV LED and a linear variable filter (LVF), was developed for oil slick detection in a non-contact way. The two MCs are used to transmit UV light and collect fluorescence above the oil slick, respectively, and the angle between them is 45 degrees (V-shaped MCs). By employing MCs, the detection signal-to-noise ratio (SNR) can be improved by 34.5 times, and the limit of detection (LOD) of oil slick thickness is as low as 0.035 µm. The relationship between the fluorescence signal and the oil slick thickness features good linearity (R<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> = 0.998) in a range of 0.035 ~ 20 µm. The spectrometer would be suitable for online monitoring marine oil spill.