Frozen Holmium Oxide Suspension
Frozen solutions are compared to their thawed counterparts to prove the utility of the CLARiTY even with ice crystals present.
Potassium ferricyanide frozen in test tube:
Potassium ferricyanide room temperature in test tube:
Holmium oxide nanopowder frozen in test tube:
Holmium oxide nanopowder in water at room temperature in test tube:
Frozen Solution & Oats Data
Oat Seedling Experiment
Using Oat seeds grown in darkness to study production of pigments
Problem: How does one learn about production of pigments in the cotyledon?
Oat seeds were grown in wet cheesecloth in a dark environment at 22-24⁰ C for 10 days.
Oat seed cotyledons are studied using absorbance spectroscopy after irradiation with visible light.
Sprouts were fitted in the 10 x 75 mm glass test tubes in the dark, and loaded in the DSPC cell in the way to protect the sample from room lights (photo taken after experiments were finished:
Instruments and data collection:
OLIS CLARiTY 1000
Light Source 75 W Xenon lamp; Double grating Monochromator, 3nm BandPath. The spectra has 400 data points with 0.5 sec collection time per point (full scan 250 seconds). The light was blocked with the slit between every scan and during the sample loading. Sample irradiation was achieved by selecting the appropriate wavelength on the monochromator.
Note: because of the nature of current sample presentation in the DSPC cell (i.e. the sample did not fill the DSPC as is required for “absolute absorbance” value computation), the reported Absorbance values are “apparent absorbance”.
The dark spectrum was collected after the sample was inserted into the DSPC:
This next spectrum was collected after 1 min exposure to the 665 nm light:
Next step. Sample was illuminated for 5 minutes, then a single scan was collected, afterwards 10 additional spectra were collected in a 42 minute time frame. The difference spectra were computed by subtracting a single scan after 5 min illumination from each of the later scans.
The kinetic of the difference spectral changes after 5 minutes of irradiation with 665nm light. Inset – raw spectra: