No description available.

Three new quantitative Fourier transform infrared (FTIR) spectroscopic methods were developed to measure key lubricant condition monitoring parameters; total acid number (TAN), total base number (TBN), and moisture (H2O). All methods employ a common sample-handling accessory and are based on the addition of specific reagents designed to react stoichiometrically with target species in oils, with quantification being carried out using differential FTIR spectroscopy. The combined use of a stoichiometric reaction and differential spectroscopy overcomes the need for a reference oil, which has traditionally hindered quantitative analysis of lubricants by FTIR spectroscopy. Potassium hydroxide, trifluoroacetic acid (TFA) and 2,2-dimethoxypropane (DMP) were the stoichiometric reagents used to develop the FTIR TAN, TBN and H2 O methods, respectively. Calibrations were developed using either peak height measurements or partial least squares (PLS) regression and the methods were validated using standard addition techniques, as the ASTM (American Society of Testing and Materials) standard methods were not sufficiently reproducible to make valid comparisons. Validation of the methods indicated that the TAN, TBN and H2O methods had accuracies of +/-0.095 mg KOH/g, +/-0.5 mg KOH/g and +/-32ppm respectively and corresponding reproducibilities of +/-0.05 mg KOH/g, +/-0.17 mg KOH/g and +/-22 ppm. The TAN, TBN and H2O methods were implemented on a Continuous Oil Analysis and Treatment (COATRTM) System, integrating instrumentation, software and sample handling so as to provide packaged, user and environmentally friendly analytical methods that are alternatives to conventional ASTM wet chemical methods.

Bibliography: pages 46-50. / A sequential atomic emission spectrometer, using a low power (1,7 kW) argon-cooled inductively coupled plasma (ICP) system, was used for the determination of wear metals and additives in lubricating oils with xylene as solvent. The modified Simplex method was applied to establish the optimum experimental parameters for 21 individual spectral lines. The optimization was applied to single element analysis on the basis of net signal-to-background ratio (SBR) using the standard cross flow nebulizer and then repeated using the high solids Babington-type nebulizer. Weighted compromise conditions were calculated resulting in a maximum loss of 50% in the SBRs of the individual elements. These conditions result in an analytically useful plasma that gives low detection limits and high sensitivities for the analysis of metals in lubricating oils. Analytical parameters such as detection limit and analytical range for the analysis of 17 elements present in lubricating oil as wear metals or contaminants and 4 other elements present in the most common lubricating oil additives were determined. The detection limits reported here for oil in xylene are of the same order as the published limits for aqueous and for oil-in-MIBK solutions. However, the most valuable property of the ICP-AES was found to be the astounding analytical range which allows determinations to be made over a large concentration range without the need for serial dilutions. The effect of sample preparation was investigated by employing ultrasonic agitation prior to withdrawing the used oil from the sample vial. An upward trend was found in the element concentrations from manual shaking of the oil to ultrasonic agitation, indicating a particle distribution effect. Finally, the technique was tested successfully by analysing an NBS reference standard and by participating in several "round robin" used oil analyses. ICP-atomic emission spectrometry can be successfully applied to the analysis of metals in lubricating oils with a speed, accuracy and precision which at least equals, and even improves upon any other of the established techniques.

M. Tech. Chemistry. / Methods developed for the analysis of used oil can play a vital role in monitoring the condition of engines and may help to improve overall equipment effectiveness. Quantification of trace elements in used lubricating oil forms a vital part in monitoring engine conditions and impact on the environment. The main objective of this work is to investigate methods used for the accurate determination of trace elements in lubricating oils. In this study, inductively coupled plasma-optical emission spectrometry (ICP-OES) was used for the determination of trace elements (Ag, Ba, Cu, Mn and Ni) in lubricating oils.

Investigations of new applications of the inductively coupled plasma (ICP) for analytical atomic emission spectroscopy are performed. Research efforts are focused in three major areas: emissions below 185 nm, analysis of wear metals in lubricating oils and use of the ICP as a selective detector for high performance liquid chromatography (HPLC). A unique plasma coolant tube containing a side arm which allows direct observation of the discharge is used to investigate emissions in the vacuum ultraviolet (VUV) spectral region between 120 and 185 nm. Emissions from elements which do not emit radiation in the visible region are observed. Oxygen emissions at 130 nm, nitrogen at 149 and 174 nm and carbon at 155 and 165 nm make up the background spectrum. These elements are present as impurities in the argon gas used to sustain the ICP discharge. Fifteen emission lines from bromine are observed. Those at 153 and 163 nm are the most intense. Sulfur also has fifteen emission lines and chlorine has nine in this region of the spectrum. The VUV region is found useful for observation and potential analysis of many elements. A heated sample introduction system attached to a Babington nebulizer is investigated as a means to aerosolize lubricating oils for introduction into the ICP. This allows direct analysis of wear metals in oil samples without requiring the usual sample dilutions. Several commercial brands and weights of motor oil are spiked with iron in order to evaluate this system. Heating the oil as it enters the nebulizer is found to increase the nebulization efficiency as much as sixtyfold in some cases. Differences in nebulization efficiency due to viscosity are almost entirely eliminated through the application of heat. A linear calibration curve extending three orders of magnitude from a detection limit of one ppm iron is determined. The ICP is used as a selective detector for HPLC. Nucleotides separated by anion exchange chromatography are determined in the ICP by observing phosphorus emissions. Methanol and acetonitrile used for reverse phase HPLC are successfully run in the IPC. The method is evaluated by using the ICP to determine phosphorus in compounds separated by using reverse phase conditions. The HPLC is used to separate organic interferences from several silicone samples using reverse phase conditions allowing the ICP to accurately analyze silicon content.

M.Sc. / Emulsions are not widely used in industry for wear-metal-in-oil determinations and this study was undertaken in order to evaluate such a possibility. The use of emulsified standards was compared to aqueous standards for the calibration of an emulsified used lubricating oil sample. The traditionally used methods of ashing in a muffle furnace and dilution with the organic solvent, xylene were also evaluated in comparison with the emulsion methodology. Inductively coupled plasma optical emission spectrometry (ICP-OES) was used for the wear-metal-in-oil analysis. The performance characteristics of each method were compared for the following metals: AI, Cr, Cu, Fe, Ni, and Pb. The used oil sample and emulsified standards were acid treated and emulsified in water {1% wlw) using tetralin as solvent and triton X-100 as surfactant. This evaluation included the calibration characteristics, precision and accuracy obtained, as well as the results of recovery studies. The emulsification method was found to be comparable to the ashing and dilution methods in terms of calibration and only Cr, Cu, Fe and Pb concentrations were found. The precision of the emulsification method was found, in general, to be close to or less than 2% RSD. The used oil matrix also contained leaked petroleum from a problem car engine. An accurate determination of lead was consequently impossible since the high lead content led to sedimentation. The use of the internal standard, indium, was evaluated for its effectiveness in correcting possible matrix effects that were evident from the results obtained in the recovery studies. The recovery studies showed the Cr and Pb determinations to be adversely affected by internal standardization. An alternative approach for matrix effect correction, the common analyte internal standardization (CAIS) method was also investigated. This method held promise for allowing the use of aqueous standards, instead of oil or emulsion standards, for the calibration of the emulsified oil samples. Three different applications of the CAIS technique were investigated and all proved unsuccessful.

Oil analysis is a broad field comprised of hundreds of individual tests that provide meaningful benefit by assessing one or more properties of lubricants or machines. Many tests are performed on new types of oil during research and development. The lubricants chemical, physical, or lubricating properties are validated for quality control purposes and product performance classification. Much of the research in this area is devoted to the online oil degradation systems which allow getting a prompt response about the condition of lubricant. This thesis investigates the concept for monitoring oil degradation with a vibrating Kelvin probe technique. The Vibrating Kelvin probe method for measuring the work function of metals has been used since 1932. Among the applications of this technique are adsorption, corrosion, friction and other studies. A novel application of this method is proposed in this thesis. The vibrating Kelvin system was created with one static surface acting as a sampling surface and the other one electrically isolated. The interaction of the oil with one of the surfaces of a capacitor results in a signal which is synchronously measured. The oil molecules adsorb on the surface of one of the plates and form a space charge layer which changes the work function of that surface. Oil prepared by intentional oxidation was used to evaluate and to monitor the ability to see changes in oil.

No description available.