Resources Contact Us Home
Browse by: INVENTOR PATENT HOLDER PATENT NUMBER DATE
 
 
Flow-injection gradient dilution for obtaining UV spectra of concentrated solutions










Image Number 10 for United States Patent #5801820.

The invention relates to methods and apparatus for precise dilution of concentrated samples enabling their spectra to be obtained. The spectra thus obtained may then be used for calculation of the aromatic hydrocarbon content in the concentrated samples. This invention comprises an arrangement of computer-controlled pumps, an injection valve, a mixing chamber, a flow cell (these components are known as "the manifold") and a scanning spectrophotometer, with a sophisticated computational software program. The arrangement generates a reproducible, well-defined gradient from a concentrated sample which is continuously scanned and, using the computational software, allows the spectrum of the sample to be derived, even where the majority of the spectrum for the undiluted sample has an absorbance greater than the upper measurable limit of the spectrophotometer. All of the methods described in prior art publications differ from the present invention by their reliance on calibration (the adjustment of factors used, by comparing spectral data for a standard with its reference data) or characterization (measurement of the characteristics of the system, e.g., flowrate and mixing volume, and inclusion of these values in the calculation) of the systems for defining dilution factors, due to measurement of a single species/wavelength. The present invention requires no calibration/characterization for single species measurement since multiparameters (absorbance at many wavelengths) are monitored or conversely, can be used to obtain spectra of highly concentrated samples and therefore determine multiple species. None of the previous systems were used to obtain spectra per se.








 
 
  Recently Added Patents
Chitosan hydrogel derivatives as a coating agent with broad spectrum of antimicrobial activities
Systems and methods for managing fleet services
Means to securely fixate pacing leads and/or sensors in vessels
Electronic system with vertical intermetallic compound
Digital broadcast receiver and method for processing caption thereof
Segmented display panel and camera with segmented display
Sunglasses
  Randomly Featured Patents
Arrangement for electrical energy transmission in a gun
Process for the preparation of the highly pure enzyme kallikrein from swine pancreas extracts
Cradling apparatus for portable communication device
Double-walled damping structure
Showerhead support
Reinforced soil retaining wall and connector therefor
Tool rack having two stories of rack members
Quadrature mixer method and apparatus
Support brace
System and method for dynamically adjusting read ahead values based upon memory usage