University of Utah Research Foundation

Boc Health Care, Inc.

Process Instruments, Inc.

Joel M Harris

Scott D Miles

Lee Morgan Smith

Douglas A Christensen

Richard Dennis Rallison

Henry S White

Ryan J White

Robert E Benner

Donald E Gregonis

John R Mitchell

Joshua R Wayment

Carl W Johnson

Fritz J Knorr

Norman J Dovichi

A method of preventing non-specific adsorption of proteins onto a surface can include providing a substrate that has a surface on which surface groups are attached. A solution can be applied to the surface that includes a protective reagent having a terminal functional group exhibiting a dipole moment. A monolayer comprising the protective reagent is assembled on the surface by reacting the protective reagent with the surface groups, thereby creating a protected surface. The protective reagent alone is sufficient to confer to the protected surface an increased resistance to adsorption of proteins.

Surfaces resistant to non-specific protein adsorption and methods of producing the same

Apparatus and methods for analyzing the chemical composition of fluid streams using Raman spectroscopy are disclosed. The invention is particularly useful in continuously analyzing a fluid stream containing petroleum products, aqueous or biological fluids. The apparatus includes a laser source for producing light having an excitation wavelength. The light is introduced into a bundle of optical fibers connected to a tubular Raman enhancement cell. A transparent optical element (lens and/or window) acts as a barrier element to isolate the flowing sample stream from the optical components. The Raman enhancement cell is configured to allow continuous sample fluid flow therethrough, and it is preferably lined with a material having an index of refraction less than the index of refraction of the fluid stream. Scattered light from the enhancement cell preferably exits the optical fibers as a linear optical signal. A Raman spectrometer passes the optical signal through an excitation wavelength filter, an optical slit, and a volume holographic transmission grating with an aberration correction device before transmitting the optical signal to a charge coupled device array which converts the optical signal into a corresponding electronic signal. The electronic signal is analyzed and converted by computer into a representation of the chemical analysis of the fluid stream.

Raman spectroscopy apparatus and method for continuous chemical analysis

A gas analysis cell positioned within an optical resonant cavity in a gas analysis system is disclosed wherein the cell includes a flow of buffer gas which forms a 'dam', thereby protecting the optical elements in the analysis system. The analysis cell includes an inlet for introducing a gas sample into the analysis chamber of the cell. Two buffer gas inlet ports, one on each end of the cell, are provided to introduce a flow of buffer gas which is directed past optical elements in the system adjacent the ends of the cell. Two output ports are located at the ends of the analysis chamber to remove the buffer gas and gas sample mixture. The flow of buffer gas acts to confirm the gas sample within the analysis chamber and reduce adverse effects which occur when the gas sample comes in contact with the optical elements of the system. By providing a constant non-turbulent flow of gas adjacent the system optics, adverse changes in index of refraction are avoided, thus reducing beam steering and Schlieren effects which can occur when Brewster windows or other optics are used to constrain the gas sample within the analysis cell. The buffer gas flow in the analysis cell of the present invention eliminates the need for gas cell windows which have intrinsic losses. This in turn minimizes losses which cause lower circulating intracavity power and signal strength.

Gas analysis system having buffer gas inputs to protect associated

A method and apparatus for resolving overlapped chromatographic peaks or other overlapped data obtained from operation of a differential migration apparatus used to analyze a substance whose composition is to be determined. The invention involves using a second analytical apparatus, such as a spectrometer, to supplement the data obtained from the basic differential migration apparatus. A multi-channel detector is used to monitor and record the various sets of data obtained from these apparatus. Data corresponding to regions of overlap identified by the apparatus are assembled in a measured data set. An estimated data set is then compiled describing the estimated migrational time behavior of each of a plurality of compounds present within the overlapped region. An identifying data set is then calculated based upon the estimated data set and the measured data set. This identifying data set contains unique identifying data, such as spectral data, corresponding to each compound present within the overlapped region. Errors in the identifying data set are minimized through an iterative process that modifies the estimated data set with each iteration. When the error is reduced to an acceptable level, the identifying data set serves to finally determine the number and identity of the compounds present within the region of overlap, i.e., resolve the overlapped peak, matrix techniques are advantageously used to handle and manipulate the large amount of data that is measured and generated. A computer may also advantageously be used to facilitate the speed and accuracy with which the matrices may be manipulated.

Multichannel detection and resolution of chromatographic peaks

A technique for detecting very small quantities of particular materials by absorption of visible, ultraviolet or infrared light from a laser source is disclosed. The technique takes advantage of the thermal lens effect, i.e., a thermally induced alteration of the index of refraction, which occurs whenever a laser beam is passed through an absorbing medium, especially fluids. A converging beam derived from a coherent, collimated beam, e.g., a laser beam in the infrared, visible, or ultraviolet light range, is passed through a reference cell. The converging beam is slightly modified by a change in the index of refraction due to the thermal lens effect occurring within the reference cell. The modified beam is passed through a sample cell containing the identical medium as that in said reference cell with an additional material therein sought to be identified. The reference cell and sample cell are located at points in the beam path such that any modification in the beam caused by a change in the index of refraction of the medium in the reference cell is cancelled by the same medium in the sample cell. Any detectable modification in the beam, e.g., expansion (or divergence), as it evolves from the sample cell is due to the thermal lens effect caused by the material sought to be identified.

Calorimetric trace analysis by laser induced thermal lens method

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Salt Lake City, UT, United States of America

Joel M Harris