Development and validation of an environmentally friendly attenuated total reflectance in the mid-infrared region method for the determination of ethanol content in used engine lubrication oil.

Lubricating oils are crucial in the operation of automotive engines because they both reduce friction between moving parts and protect against corrosion. However, the performance of lubricant oil may be affected by contaminants, such as gasoline, diesel, ethanol, water and ethylene glycol. Although there are many standard methods and studies related to the quantification of contaminants in lubricant oil, such as gasoline and diesel oil, to the best of our knowledge, no methods have been reported for the quantification of ethanol in used Otto cycle engine lubrication oils. Therefore, this work aimed at the development and validation of a routine method based on partial least-squares multivariate analysis combined with attenuated total reflectance in the mid-infrared region to quantify ethanol content in used lubrication oil. The method was validated based on its figures of merit (using the net analyte signal) as follows: limit of detection (0.049%), limit of quantification (0.16%), accuracy (root mean square error of prediction=0.089% w/w), repeatability (0.05% w/w), fit (R(2)=0.9997), mean selectivity (0.047), sensitivity (0.011), inverse analytical sensitivity (0.016% w/w(-1)) and signal-to-noise ratio (max: 812.4 and min: 200.9). The results show that the proposed method can be routinely implemented for the quality control of lubricant oils.

Peroxides in mineral oil used for in vitro fertilization: defining limits of standard quality control assays.

PURPOSE: To determine the relative sensitivities of the 1 and 2-cell mouse embryo assays (MEA) and the human sperm motility assay (HSMA) for peroxides in mineral oil. The effect of peroxide on blastocyst cell number and apoptosis was also studied. METHODS: One and two-cell MEA and HSMA were performed using mineral oil containing cumene hydroperoxide (CH). RESULTS: The 1-cell MEA was twice as sensitive as the 2-cell MEA and 20-times more sensitive than the HSMA for CH in mineral oil. The sensitivity of the 1-cell MEA doubled when embryos were cultured individually versus group culture. CH decreased blastocyst cell number in a dose dependent manner. CONCLUSIONS: Individually cultured 1-cell embryos had the highest sensitivity for peroxides in mineral oil. Current quality control assays, including group cultured murine embryos and human sperm motility, have limited sensitivity for peroxides in mineral oil and may not detect levels of peroxides that cause sub-lethal cellular damage.

New low-index liquid refractive index standard: SRM 1922.

A new standard for the calibration of refractometers has been developed. Standard Reference Material (SRM) 1922 is a mineral oil with a refractive index nD = 1.46945 at 20 degrees C, which is within the range of the Brix scale (% sucrose). The change in refractive index with temperature (dn/dT) has been characterized for the range 15 degrees C to 35 degrees C to allow for calibrations within that range of temperatures. The refractive indices were measured at 5 wavelengths in the visible spectrum by using the method of minimum deviation with a +/- 2-3 x 10(-5) uncertainty at 20 degrees C. The values of nD and dnD/dT were determined by fits of a two-term Cauchy function to the values at the measured wavelengths with a +/- 6 x 10(-5) uncertainty in nD at 20 degrees C.

Treatment of feline otoacariasis with 2 otic preparations not containing miticidal active ingredients.

Two otic products not containing miticidal active ingredients were compared for the treatment of otoacariasis in 20 cats. It was concluded that treatment of feline otoacariasis can be achieved using products with an oil/wax base in conjunction with routine ear cleaning and total body parasitacide treatment.