Variable Path Length Slope Spectroscopy System

2 Variable Path Length Slope Spectroscopy System 

Absorption spectroscopy is usually performed using a fixed path length and dilutions of standards and samples, to prepare a calibration curve and keep the absorbance readings in the linear range, as discussed in Chapter 2. Dilutions are subject to error and can be a problem when diluting from a concentrated solution of high viscosity, since displacement pipettes are usually not calibrated for high-viscosity solutions. 

The Fibrette and vessels are made of quartz, giving a wavelength range of 190-1100 nm plastic vessels are also available for either the UV or VIS-NIR range. Minimal sample volumes (1-3 pL) can be measured and the sample recovered. 

Computer-controlled motion moves Fibrette up or down in 0.005 mm steps to dynamically change the pathlength for measurement 

Pathlength (I)i Defined by the distance from the Fibrette tip to the bottom of the sample vessel — 

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S.2.6.2 Variable Path Length Slope Spectroscopy System... 

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