Optimization of Determination of Petroleum Samples in Surface Water, Groundwater and Wastewater by Fluorescence Spectrophotometry

The analytical method for the determination of petroleum samples in water by fluorescence spectrophotometry was improved. The petroleum samples in water was extracted with n-hexane, purified by magnesium silicate, and detected using a fluorescence spectrophotometer. Under optimal conditions, the calibration curve of the method showed good linearity, the correlation coefficient was 0.999, and the detection limit was 0.007 mg/L. The method has been applied to determinate petroleum samples collected from different factory surface water and groundwater. The average spiked recoveries were among 87.5%~110.0%. Comparing ultraviolet and infrared methods with fluorescence spectrophotometry, the relative deviation of surface water and groundwater was 5.3%~13.3%, and the wastewater was 1.7%~19.5%. The improved method is accurate and sensitive, and can be used as a supplement, to the petroleum samples in water monitoring standard system.