Determination of oil and grease by solid phase extraction and infrared spectroscopy

An alternative procedure using solid phase extraction for the analysis of o il and grease in waters was developed. The use of a PTFE filter as a solid phase allows retention of oil and grease and further analysis of carbon-hyd rogen bonds can be run over the filter. This method avoids the use of any k ind of solvent. Experiments used n-hexadecane as a standard oil in differen t water matrices. The detection limit was 0.034 mg/l. Recoveries of diesel oil, pump vacuum oil, olive oil, sunflower oil and mixture of oils, depend strongly on the oil used for the calibration line, but in general satisfact ory results were obtained. Recoveries of isooctane and benzene, used in the standard methods procedure, gave poor results. The method is fast, clean a nd sensitive, and represents a way of measuring oil and grease in water wit h high reproducibility. The method was compared with standard methodologies in tests involving real samples. (C) 1999 Elsevier Science B.V. All rights reserved.