A few questions asked about the CLARiTY product line
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QUESTIONS ABOUT CLARITY:
Are the answers that a cuvette and integrating cavity return the same?
YES, if there is zero scatter by the sample. Then, the two methods are equally successful and the same answer is returned.
NO, if there is scatter by the sample. Scatter is caused by light changing direction due to interaction with particles in the suspension.
If the scattering particles have no absorbance at the wavelength(s) of interest, then the difference between the CLARiTY and your cuvette will be due only to the scattering caused by light deflection from the detector.
If the scattering particles do absorb at the wavelength(s) of interest, the difference is cause by the absorbance of the solution and the absorbance of the particles plus the scattering caused by light deflection from the detector.
Do an experiment here to determine if your particles themselves absorb. Suspend the particles in your solvent without the analyte. Measure the absorbance. Vary the concentration of particles in the suspension. Measure the absorbance and plot the curve.
If the scattering particles have no absorbance at the wavelength(s) of interest, then the difference between the CLARiTY and your cuvette will be due only to the scattering caused by light deflection from the detector.
I don't want to dilute. What is my alternative?
Same as with a cuvette spectrophotometer: reduce the pathlength. Choices available with CLARiTY support absorbance/cm readings up to 100 A.
What is the upper limit of color?
You can find the dynamic ranges of each individual CLARiTY cuvette style in the Specifications section.
Should I use the filled DSPC, a test tube, or a flow-through cell?
Using a filled DSPC is optimized for measuring the absorbance of dilute samples. The ~30x amplification in the 8 mL cavity means that low concentration clear solutions may be analyzed as easily as turbid suspensions.
Test tubes are optimized for situations where the amplification effect of the full cavity is either not desired or unnecessary. Series of scattering suspensions introduced in this way may be externally prepared and measured rapidly in succession. This method has the added benefit of utilizing disposables, for those formulations which risk staining quartz or glass.
The Flow-Through DSPC (FT-DSPC) is designed for two primary situations: exceedingly high absorbance environments or for monitoring continuous processes (when coupled with a pump and plumbing). Many available cuvette pathlengths, fixed at the time of manufacture, allow for dynamic range selection from 0.5 Absorbance/cm to over 100 Absorbance/cm.
How do I clean between measurements?
DSPC: Withdraw the sample with a pipette and introduce water or another appropriate solvent. Detergent solutions, basic or acidic aqueous solutions are all viable. Rinse with fresh solvent.
Test tubes: Pour out the sample and introduce water or another appropriate solvent. Detergent solutions, basic or acidic aqueous solutions are all viable. Rinse with fresh solvent. Store inverted.
Flow-through DSPC: The displacement flow of samples in the FT-DSPC allows the user to pass a series of samples without requiring cleaning between measurements. Flush with water or another appropriate solvent. Detergent solutions, basic or acidic aqueous solutions are all viable. Rinse with fresh solvent.
