DSPC Options
The DeSa Suspension Presentation Cavity (DSPC) is a new sample holder developed at OLIS by Dr. Richard J. DeSa which creates an environment for the sample with complete immunity to scatter. The design follows that of holders called integrating cavities (see “pre-CLARiTY publications”). They differ from integrating spheres in key ways, including requiring no calibration and having known effective pathlengths and thus allowing calculation of accurate absorbance.
Most DSPCs include round bottom quartz flasks of 1 mL, 4 mL, or 8 mL volume returning
effective pathlengths of approximately 5, 20, & 30 cm, respectively. Thus, suspensions can be extremely dilute. Stirring is built-in.
Sample is added and removed most commonly using a pipette. An automated alternative is the OLIS Titrator. Cleaning solutions are introduced in the same ways. Since the integrating cavity is quartz, anything from detergent to sodium hydroxide are suitable.
Others shapes include variations on round bottom and flat bottom test tubes of various diameters to accommodate coated quartz rods to grapes.
The DSPC is created in two halves with the upper portion containing the sample cavity. One can easily exchange one cavity for another to accommodate a range of sample types. Within the dual beam CLARiTY spectrometers, different volume or shaped DSPCs can be standard, as matched design is not required for successful reference readings.