This dissertation deals with an optimization of TPH (Total Petroleum Hydrocarbon) analysis methodology for samples of contaminated sands, validating the infrared detection technique through the use of Infracal TOG/TPH equipment. Tests were validated using Marine Fuel 380 oil, density 0.987 g cm-3 and viscosity 5313 cP at 20 Celsius Degrees. This oil sample was kindly supplied by Petrobras Research Centre (CENPES), and is the same oil that leaked from a pipeline in REDUC Refinery on January 2000, contaminating several beaches in Guanabara Bay, including Anil and Mauá. The optimized methodology was applied on 110 sand samples contaminated with the aforementioned oil, and TPH were determined within the range of 10.0 to 155.0 g kg-1. The validation results suggested that the methodology performance was adequate for this application. Amongst the metrological parameters obtained from this work, the detection limit, 9.44 mg l-1, was a plus; since it was far below to the concentration range obtained from this samples.