Page 5 - Shimadzu Lightway

Shortening Experimental Process Easy Measurement

Conventional measurement requires a lengthy process using a chemical It can monitor spectral changes* during the photoreaction process in real time.
actinometer but Lightway includes functionality that calibrates the Measurements can be started by specifying mainly three parameter settings
™
number of irradiated photons, eliminating this process. (measurement interval, measurement time, and number of irradiated photons),
*Using a chemical actinometer involves sample adjustment process steps, such as crystallizing, air which makes it easy to operate even for rst-time users. Also, a dialog box is
drying, and diluting samples, and then measuring the number of photons in a dark room and displayed whenever a button is pressed to help navigate operations.
calibrating the number of photons irradiated on the sample.
* Results for speci c wavelengths can be graphed as a function of time.
About 6 hours ＋ About 1 hour ＋ About 5 hours = Total of about 12 hours

Irradiate light onto Calculate number
Conventional Adjust chemical actinometer sample and measure of photons
Method* the change in absorbed by
absorbance. sample.
Use chemical actinometer to
calculate number of irradiated photons.

10min

About 10 minutes
Lightway
Irradiate reaction light onto sample and
automatically calculate the number of
photons absorbed.

* Conventional method requires a chemical actinometer.

Photoreaction Quantum Yield:
A gas chromatograph (GC) is used to measure the number
Number of of gas molecules generated and a liquid chromatograph
Photoreaction molecules generated (LC) to measure number of liquid molecules.
quantum yield Number of
Important indicator of Photons absorbed * Lightway accurately determines the number of photons
absorbed by the sample, based on the number of
photoreaction ef ciency for photons irradiated and the absorption spectrum.
photocatalysts, etc.
For a comparison to data obtained with the conventional method using a chemical actinometer, refer to LAAN-A-UV-E041 Application News Time-course measurement results
bulletin No. A478. Irradiated light settings at a monitored wavelength Measurement results for all spectra
Application News bulletins are available from the Shimadzu website.
* The values may not be correct if the sample has scattering properties or is absorbed by the solvent. LEDs provide stable, bright, and long-lasting Time-course changes in the absorbance at any No bothersome settings are necessary. Only the
irradiation light. That means reliable results can be particular wavelength can be determined measurement interval and measurement time need to be
obtained anytime. Also, experimental reproducibility can instantaneously. By specifying the speci c wavelength as speci ed for spectra measurement conditions. The
be increased by specifying the quantity of light irradiated. the monitored wavelength before starting a measurement, minimum measurement interval setting is 0.1 seconds.
spectral changes can be displayed as a function of time, That means spectra from 250 to 800 nm can be acquired
so that the end of the reaction can be con rmed more within 0.1 seconds to track reactions quickly.
quickly and the reaction rate can be con rmed more
intuitively.
The PQY- Meas software that comes standard with the system offers the following three modes.
™
Photoreaction Measurements
Measures a spectrum while the sample is irradiated by the irradiation light source.
Spectral Measurements
Measures a spectrum after the sample is irradiated by the irradiation light source. It can also perform regular spectral measurements
as a spectrophotometer.
Calibration Curve & Quantitation
Creates a calibration curve from a standard sample to determine concentrations in unknown samples.

Lightway
4 PQY-01 Photoreaction Evaluation System 5