uv vis spec

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AppliedTechnologyDevelopmentDivision

UV/VIS SPECTROPHOTOMETER

MECASYS, Co., Ltd.


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What is UV/VIS?What is UV/VIS?

Electromagnetic Spectrum

X-Rays UV VIS NIR IR Micro wave

200nm 400nm 700nm 2500nm 500 m

E0

E1

E= E1 -E0

Molecular rotationMicro Wave

Molecular vibrationIR

Outer ElectronUV/VIS

Inner ElectronX-Rays

Type of TransitionType of Radiation


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Principle of UV/VIS SPECTROPHOTOMETERPrinciple of UV/VIS SPECTROPHOTOMETER

Principle

Light Intensity Change : By Absorbance or Transmittance

Quantity : Using Absorbance

I

I

Sample


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LambertLambert--BeerBeers Laws Law

Transmittance, t

t / 0 = t

Absorbance, A

log 1 / t = A

Lambert Beers Law

A = abC, A = bC

b : Sample Path length, C : Sample Concentration,

a : Absorbance Constant

: Molecular Absorbance Constant

I0 It

Sample (Conc.C)

Path lengthb


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Deviations in absorptivity coefficients

at high concentrations (>0.01M) due to electrostatic interactions

between molecules in close proximity

Scattering of light

due to particulates in the sample

Fluorescence or Phosphorescence of the sample

Changes in refractive index at high analysis concentration

Shifts in chemical equilibria as a function of concentration

Stray light

Limitation of LambertLimitation of Lambert--BearBears Laws Law


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Application ofApplication ofUV/VIS SpectrophotometerUV/VIS Spectrophotometer

Quantity analysisQuantity analysisQuantity analysisQuantity analysis

(Using a Spectrum)

Quality analysisQuality analysisQuality analysisQuality analysis

(Standard Curve)

Chemical analysis

Food safety analysis

Blood analysis

DNA/RNA Conc. analysis

Residual Pesticide analysis

Residual chlorine analysis


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Functions of SpectrophotometerFunctions of Spectrophotometer

ABS/%T/CONC

Measuring Absorbance/Transmittance/Concentration

Survey Scan

Measuring Absorbance(Transmittance) Spectrum

Standard Curve (Calibration Curve)

Determining Proportional Constant between ABS and Conc

Simple Kinetics

Measuring Time Dependent ABS Variation

ABS Ratio

Measuring ABS Ratio (DNA/Protein)


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Structure of UV/Visible SpectrophotometerStructure of UV/Visible Spectrophotometer

Light

source

Lens

or

Mirror

Monochromator

Detector

Sample


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ExampleExample

Spectrophotometer

Light

SourceMonochromator

Sample

Compartment

Sensing

Part


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Light SourceLight Source

Deuterium Arc Lamp

UV Region Wavelength Range :

190~420nm

Tungsten LampTungsten LampTungsten LampTungsten Lamp Wavelength Range : Part of the UV and the whole of the VisibleWavelength Range : Part of the UV and the whole of the VisibleWavelength Range : Part of the UV and the whole of the VisibleWavelength Range : Part of the UV and the whole of the Visiblerangerangerangerange ((((350 ~ 2,500350 ~ 2,500350 ~ 2,500350 ~ 2,500nm)nm)nm)nm)

Xenon Lamp Wavelength Range : 190~800nm

Tungsten LampTungsten LampTungsten LampTungsten Lamp


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MonochromatorMonochromator

Accepts polychromatic input light from a lamp and outputs

monochromatic light Components : Entrance slit, Dispersion device, Exit slit

Entrance slit

Exit slit

Dispersion device

White Light

Monochromatic

Light


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Dispersion Device (I)Dispersion Device (I)

Filter

Absorptive Filter Interference Filter : FWHM 10

50 nm


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Dispersion Device (II)Dispersion Device (II)

Prism


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Dispersion Device (III)Dispersion Device (III)

Grating

Plane Grating, Concave Grating


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Monochromator structureMonochromator structure

Littrow mounting

Slit

Grating

Mirror

Czerny-turner mounting

Mirror Mirror

Grating Entrance

slit

Exit slit


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Monochromator DesignMonochromator Design

Modified Czerny-Turner Type

- Focal Length : 200mm- Sine Drive Mechanism

- 1nm Bandwidth

Czerny-Turner Type

- Focal Length : 100mm- Direct Drive Mechanism

- 4nm Bandwidth


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Absorption CellAbsorption Cell

Receptacle for Sample.

Material Quartz, Fused Silica(Using over

190nm)

Glass (Using Over Visible Region)


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DetectorDetector

Photodiode

Photodiode & CCD

PMT(Photo Multiplier tube)


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Type ofType ofUV/VIS SpectrophotometerUV/VIS Spectrophotometer

Single Beam Type Double Beam Type


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Type ofType ofUV/VIS SpectrophotometerUV/VIS Spectrophotometer

Grating

Light Sample

Detector

Scanning type : PDA type :

Grating

Light

Multi channel

DetectorSample


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Specifications ExampleSpecifications Example

Spectral Bandwidth : 1 nm

Wavelength Range : 190 1100 nm

Accuracy : 0.5 nm

Reproducibility : 0.1 nm

Photometric Range : -0.3 3.0 Abs (0 125 %T)

Accuracy : < 1% at 1 Abs

Reproducibility : 0.001Abs

Stray Light :


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Accessories (I)Accessories (I)

Multi-Cell Holder Sipper System


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Accessories (II)Accessories (II)

Micro Volume Cell Round Cell Long Path Cell

Temperature Cell Holder, Film/Thin-Layer Holder


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Thank You!

uv vis spec

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