Hydrogen baseline shift

Water in these oils is measured over the wavelength range of 3400-3250 cm with no baseline correction applied. This range shows sensitivity to both the baseline shift due to low levels of water contamination and the hydrogen-bonded OH stretch response characteristic for higher levels of water contamination in these oils. The IR response for this lubricant class is insufficient to determine low levels of water contamination. Karl Fischer titration is recommended for low-level water determination for petroleum turbine and hydraulic oils. 

Breakdown of Ester Basestock Oils Basestock breakdown in polyol ester lubricants is observed in two IR areas. Area I around 3535 cm indicates that the breakdown products are mostly composed of weakly hydrogen-bonded alcohol or acid groups. Base stock degradation is measured over the range 3595-3500 cm A single baseline point for this measurement is taken at 3595 cm to eliminate any interference from water contamination because as water contamination increases, the baseline shifts accordingly. 

Figure 7.12 shows the FI traces taken from the 2D plots at 7.3, 3.0 and Oppm. The aromatic resonances at 7.3 ppm (bottom trace in Figure 7.12) are very well resolved, while the aliphatic and vinyl protons of cod ligand (middle trace) are broad and hidden in the baseline. The upper trace, taken at Oppm, represents the pure signal of methyl proton bonded to silicon residue. Despite the fact that 2D CRAMPS experiment enabled us roughly to assign the position of cod protons, the exact chemical shifts of other hydrogens remain equivocal. 

The amount of hydrogen required to drive 300 miles may be too low for two reasons. First, it s too low if we expect people to drive 300 miles and make significant use of onboard energy for nontravel services, i.e., mobile electricity. Second, it s too low if, in the interim while FCVs are still being developed, HEVs shift baseline consumer expectations of driving range up into the range of 500 to 600 miles. 

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