US EPA

8562305 

Journal Article 

UV-fluorescence spectroscopic method for monitoring tramp oil contamination in hot rolling emulsions. Part 2. Application of fluorescent tracers 

Januszkiewicz, KR; Bekmesian, G; Sulek, HH 

1992 

1 

Lubrication Engineering
ISSN: 0024-7154 

48 

1 

56-61 

English 

Screwdown and bearing lubricants in the aluminum hot rolling mill system were labeled with fluorescent tracers to determine the level of contamination of process lubricant using a UV-fluorescence spectroscopic technique. The tracers were selected in such a way as to absorb and emit light in two separate bands outside of the typical absorption range of rolling oil. Thus, the chosen tracers, di-2-methylpropyl ester of 3,9-perylenedicarboxylic acid, and an alkyl derivative of dinaphthol[1,2,3-c,d:1′,2′,3′-l,m]perylene-9,18- dione, show fluorescence maxima in synchronous scanning at 455 nm and 520 nm, respectively. The fluorescence maximum of the rolling oil is at 340 nm. The method involves the removal of water by evaporating the emulsion in a microwave oven and diluting the recovered rolling oil with hexane, followed by the recording of the UV-fluorescence spectrum in a synchronous scanning mode. It allows for rapid determination of the concentration and source of auxiliary lubricant contaminants which are the major components of tramp oil in the rolling oil.