System and method for determining moisture content of hydrophobic fluids

摘要

A system and method for quantitatively characterizing moisture content of an at least partially hydrophobic fluid sample. The method includes providing a dry solution of an aprotic solvent, adding at least a part of the fluid sample to the solvent to produce an extract-sample, performing infrared spectroscopic testing on the extract-sample to generate absorbance data representing at least one absorbance characteristic of the extracted sample, and generating moisture data for the sample based on the extracted sample data. The system includes a cell for holding and evaluating an extracted sample, an infrared spectrometer for measuring infrared absorbance characteristics of the extracted samples, a computer equipped with software for analyzing data outputted by the infrared spectrometer and utilizing an empirical model to derive at least one calibration equation relating data representing the absorbance characteristics of the extract-sample to unit moisture concentration, and converting the unit moisture concentration to a measure of moisture content of the sample. The method also utilizes D2O to characterize moisture content of the extraction solvent, and compensate for both moisture content of the extraction solvent and matrix effects stemming from miscibility of the hydrophobic fluid in the extraction solvent.

主权项

1. A method of characterizing water content of a hydrophobic fluid sample, comprising:
i) providing an aprotic solvent; ii) mixing the solvent of i) with water to produce a number of solvent-water mixtures with predetermined water concentrations; iii) performing infrared spectroscopic testing of the number of solvent-water mixtures to derive spectrum data for the number of solvent-water mixtures; iv) processing the spectrum data for the number of solvent-water mixtures to solve for a calibration equation that relates a spectral property measurable at a predetermined wavelength to unit moisture concentration, wherein the predefined wavelength is in the range between 1615cm−1 and 1645cm−1; v) preparing a mixture by adding the aprotic solvent of i) with at least a portion of the hydrophobic fluid sample whereby the aprotic solvent reacts with the sample to extract water from the sample of the mixture; vi) performing infrared spectroscopic testing of the mixture of v) to derive spectrum data for the mixture; vii) processing the spectrum data for the mixture as generated in vi) to measure the spectral property of the calibration equation of iv); viii) using the measure of the spectral property of vii) as input to the calibration equation derived in iv) in order to output a measure of unit moisture concentration for the mixture of v); and ix) deriving a measure of moisture content of the hydrophobic fluid sample based upon the unit moisture concentration for the mixture as derived in viii).