SPECTROFLUOROMETRIC DETERMINATION OF MINERAL OIL CONTENT IN WASTE WATERS By

The continuous and reliable control of the mineral oil content in natural waters and in industrial waste waters is very important from the aspect of environmental protection. Several analytical methods are known for the quantitative determination of 'Oil contamination in water. For the determination of higher oil contents, the simple gravimetric method can also be used, how-ever, in certain cases the reliability of the results obtained is questionable. On the other hand, the method is unsuitable for the determination of very low oil content. In the ppm-ppb region, only modern instrumental analytical methods, such as e.g. spectrophotometry, gas chromatography, IR spectrometry and spectrofluorometry can be taken into consideration.. As compared to th ~ other methods, the spectrofluorescent ~ethod has several advantages. First of all, the high sensitivity of the method ~ust be mentioned. The sensitivity of spectrofluorescent oil content determi~ation is as high as 1,ugjl oil concentration [1]. A further advantage of the method, as compared to spectrophotometry is that quantitative determinations can be carried out in a broader concentration range, and moreover, it furnishes two kinds of information on the test sample:. the excitation.sp.ectrum and the emission spectrum. Owing to these advantages, the analy-tical importance of the spectrofluorescent method steadily gains ground. In recent years, several papers discussed the extraction of the oil content of waste waters and sea water with organic solvents, and the subsequent fluo-, rescent determination of oil concentration [1-4]. According to the method, from the intensity of the fluorescent light, emitted by the luminescent compounds to be found in the oil products inves-tigated, conclusions can be drawn on the oil content present. It can be estab-lished in general that in the case of most of the mineral oils the luminescent compounds mentioned give the strongest fluorescent light emission, when an excitation light beam of 310-365 nm 'wavelength is used. Therefore, in the analytical procedure published so far, the authors always used the excitation wavelengths mentioned