This presentation gives a overview about the microvolume UV/VIS spectroscopy. Instrumentation , working ,merits, demerits, cleaning of the sample platform. mainly explains about the measurement of sample using nano or micro volume samples.
2. UV-VIS SPECTROSCOPY (OR SPECTROPHOTOMETRY)
It is a quantitative technique used to measure how much a chemical substance absorbs light.
This is done by measuring the intensity of light that passes through a sample with respect to the
intensity of light through a reference sample or blank.
MICROVOLUME UV-VIS SPECTROSCOPY
UV/VIS micro-volume spectrophotometry is a technique used to measure intensity of light with
only one drop of sample. So it is referred as to as low volume ,small volume ,nano
spectrophotometer . A wide range of concentrations is covered by automatically measured .
3. EVOLUTION OF UV /VISIBLE SPECTROPHOTOMETER :
In 1930s, American government’s interest in measuring vitamin contents using UV/Vis light.
In 1940 commercial launched UV-Vis spectrophotometer.
In 1941, Beckman introduces the DU UV-Vis spectrophotometer.
In 1946, Howard Cary is founded spectrophotometer named as Cary Instrument.
In 1950, National Technologies Laboratories changes its name to Beckman Instruments.
In 1953, Bausch & Lomb introduces the SPECTRONIC 20 UV-Vis spectrophotometer.
In 1954, Applied Physics Corporation launches the Cary 14 spectrophotometer.
In 1963, JASCO introduces the ORDUV-5 with double-beam UV-Vis capabilities.
In 1969, Cecil Instruments introduces the CE 21.
In 1979, Hewlett-Packard launches the first commercially available diode-array spectrophotometer.
In 1980, Bausch & Lomb introduces the Spectronic 2000 UV-Vis spectrophotometer.
In 1987, Pye Unicam Corporation. introduces the PU-8700 UV-Vis spectrophotometer.
4. In 1995, Hewlett-Packard launches the 8453A, diode-array spectrophotometer.
In 2000, Thermo Scientific introduces the GENESYS 10 instruments .
In 2002, Varian Inc. releases the 6000i UV-Vis-NIR spectrophotometer.
In 2003, Thermo Scientific introduces the Evolution 300 spectrophotometer, the first double-
beam xenon lamp-based spectrophotometer.
In 2004, Shimadzu introduces the SolidSpec-3700/3700DUV series of UV-Vis-NIR
spectrophotometers.
In 2005, the Nanodrop ND-1000 UV-Vis spectrophotometer .
In 2008, Shimadzu launches the UV- 1800 compact UV-Vis spectrophotometer.
In 2010, Thermo Scientific introduces the Evolution 200 Series spectrophotometer.
In2010, JASCO offers the SAH-769 One Drop.
In2011, Agilent Technologies releases the Cary 60 UV-Vis spectrophotometer.
5. MICRO-VOLUME UV/VIS SPECTROPHOTOMETER
INTRODUCTION :
Spectrophotometers are instruments used for measuring radiant or light energy, traditionally
with a quartz cuvette.
Improvements in technology now permit measuring in capillary-type or sample plate
containers.
One of such type of instrument is micro volume UV /visible spectrophotometer .
Microvolume spectrophotometers, also referred to as low volume, small volume or nano-
spectrophotometers.
7. MICRO-VOLUME UV/VIS SPECTROPHOTOMETER
WORKING:
Mettler-Toledo provides a spectrophotometer capable of performing micro-volume UV/VIS
measurement.
This instrument is capable of measuring very small volumes and highly concentrated
samples.
The method is fairly straightforward.
The sample is pipetted directly onto the measuring platform, without further dilution.
Therefore, manipulation errors are avoided.
Moreover, the selection of a specific path length allows for the measurement over a large
concentration range with as little as 1 µL of sample.
8. The measurements are performed at the micro-volume platform covered by a movable
arm mounted on the top of the instrument.
Spectrophotometer has both a micro-volume platform as well as a cuvette holder.
Depending on the selected application, the light can be directed either onto the micro-
volume platform or the 1 cm cuvette.
The transmitted light is then focused on the grating where diffraction occurs.
The diffracted light beams of different wavelengths are then directed onto the detector.
9. When the arm is in open position, the micro-volume platform can be easily accessed with
a pipette from either the left or the right side.
The curved lid on top of the instrument allows convenient positioning of the operator's
hand to securely guide the pipette tip.
During measurement, the arm is securely locked to a precisely defined path length and
cannot be opened until the measurement is completed.
The transmitted light is acquired by a detector charged coupled device .
12. CLEANING OF PLATFORM
On a micro-volume platform, samples with very small volumes, such as
microliters, can be measured
An initial cleaning of both measurement surfaces with dH2O is recommended.
dH2o is recommended for blank measurement in order to avoid interferences
with the measurements
Do NOT use a spray bottle to apply water or any other liquid to the surface of the
instrument.
13. Additional cleaning recommendations are as
follows:
Between measurements it is recommended to wipe the sample from both the upper and
lower platforms with a clean, dry, lint-free lab wipe.
Depending on the sample, a 60% isopropanol solution, ethanol or ultrapure water can be
used to clean the micro-volume platform.
If necessary, the solvent used to dissolve the sample can be applied.
When samples dried on the platform, additional cleaning can be performed using 3 µL of
0.5M HCl.
Finally , If detergents or 100% isopropyl alcohol are used, follow with 3 µL of dH2O as final
cleaning step.
14. The polished surface allows for droplet application of aqueous solutions with high contact
angle.
If the droplet flattens out, it is possible that after closing the micro volume arm the
measurement is performed through air, which will lead to erroneous measurement results.
This is visualized in the following images
For decontamination, a solution such as 0.5% sodium hypochlorite (commercial bleach
solution 1:10 diluted) can be applied to the micro-volume platform.
An additional cleansing with deionized water should follow.
18. TRICKS AND TIPS FOR ANALYSIS:
UV5NANO MICRO-VOLUME
SPECTROPHOTOMETER
Effectively clean the sample area
Properly set the pipette
Improve repeatability
Pipette smoothly on the platform
Determine rhythm and speed
19. MERITS
Accurate Microvolume Measurements
Only 1μL of sample is required for reliable measurements.
Measure Wide Concentration Ranges Fast
Double Application Power
The UV5Nano is two instruments in one: you can perform micro-volume or cuvette
measurements.
Convenient and secure
Robust and easy to maintain
With no moving parts in the optical set-up, the instrument is robust and easy to maintain.
The flat surface of the micro-volume platform makes cleaning fast and easy.
Ready to use
The Xenon flash lamp has no warm-up time. Simply power it up and start measuring.
20. DEMERITS
Light source from xenon flash lamp is expensive.
Skilled operator is required for handling sample pipette.
21. APPLICATION:
The capacity to measure volumes in the range of 0.5 to 5 ul,
Some models can measure even lower.
These instruments allow for quick and accurate quantification .
Gives accurate quantification of nucleic acids and protein samples , etc
Ideal for life science applications such as concentration and purity determinations of DNA, RNA
and protein samples
22. FUTURE OF UV-VIS SPECTROPHOTOMETERS
Future improvements in UV-Vis spectrophotometers will focus on ease-of-use,
portability, and application-specific instruments.
UV-Vis analysis of solid samples and materials continues to grow in areas
such as solar cell research, semiconductor products, and coating materials.
Advances in light sources will provide new developments in conventional
spectrophotometers and handheld UV-Vis instruments.
Further development in remote sensors will enable more types of samples to
be measured outside the laboratory.