The development of methods for oils and grease (OG) determination presents several difficulties and challenges for analytical laboratories, mainly for drinking water analysis regarding its low parametric value. FTIR method with tetrachloroethylene was developed for OG monitoring and control in several water matrices, such as natural waters (surface water, groundwater and bathing water), wastewaters and drinking water. The method was validated through the application of statistical tests and calculus of the uncertainty of the analytical assay, and proved to be a good alternative to Freon 113. Results regarding the calibration, linearity, OG recovery, precision, limits of detection and quantification, and uncertainty estimation are presented and discussed. The validated method was applied for the analysis of water samples from all studied matrices and was found to be appropriate for monitoring oil and grease in these matrices at levels higher than 0.01 mg L-1.
oils and grease; FTIR; water analysis; tetrachloroethylene
