Determining the Concentration of Oil in Water Samples by Infrared Spectrophotometry. Phase I:Sample Aging Study.

摘要

Oil in water samples of Naval Distillate Fuel Oil (NDFO) and Steam Turbine Lubricating Oil (MS 2190 TEP) at concentrations of 16 p/m and 100 p/m were studied to determine and quantify aging due to various types of degradation with time, under normal storage conditions. The samples were prepared individually from synthetic sea water and a quantity of oil which gave the desired concentration. The samples were analyzed at several intervals during an eight-week aging period. Oil concentration was determined by a method which is based on carbon tetrachloride solvent extraction and the infrared spectrophotometric measurements of the extract. Calibration curves relating the absorbance with oil concentration for the two oils were prepared from a measured quantity of oil in carbon tetrachloride. The purpose of the sample aging study was to obtain information for use in scheduling sample shipment and analysis in a forthcoming inter-laboratory study of the oil concentration measurement technique, as well as to estimate the allowable delay in sample analysis after field sampling.