Differential Optical Absorption Spectroscopy (DOAS) is widely used to determine atmospheric trace gas abundances from multi-wavelength light measurements and to quantify trace gas emissions from mobile and stationary sources [1]. Mobile DOAS is a technique initially developed to scan and measure fixed emission sources within a specific geographic area, i.e., a volcano, using a zenith-observation DOAS system mounted on a mobile platform [2]. In this work, we present ground-based detection of trace gases and the presence of spectral structures that alter the measurements of atmospheric trace gases. We also discuss various factors that affect these measurements, including wind direction, reflections, and shadows. Mobile DOAS technique was used to register the solar spectral data, and the measurement instruments were mounted on a car while circulating within and around the Refinery "La Teja" in Montevideo, Uruguay. Figure 1(a) shows an aerial view of the refinery (outlined in red). Fig. 1(b) shows an image of a refinery chimney and structures for refining. Fig. 1(c) shows the experimental setup used; a zenith-pointing telescope (1) collects the scattered light, then focuses the light into an optical fiber (2) that directs the light into a spectrometer, which acquires the spectral information and sends the data to a computer (3), where the GPS (4) coordinates are simultaneously received.