chemical analysis of metal samples using optical emission ...€¦ · typical spark sequence...

Chemical Analysis of metal samplesusing

Optical Emission Spectroscopy (OES)

Glen ThieleSpectrosource Pty Ltd

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What is Optical emission spectroscopy (OES) also known as Atomic emission spectroscopy (AES)?

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Aggregate state of matter

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Atomic physics – How photons are emitted

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Optical emission Spectrometers

ICP OES

Arc/Spark OES

LIBS OES

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Why Use Spark OES Analysis?

•Most widely used, reliable and reproducible metal analysis technique.

•Wide choice of instruments.

•Excellent LOD

•CCD based spectrometers allow a high number of elements and bases.

•Detection of N is possible with high end portable and high end laboratory spectrometers.

•Detection of O is possible with high end laboratory spectrometers.

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PMT based Spark OES architecture

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CCD based Spark OES architecture

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Spark Stand architecture

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Typical spark sequence

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Grating propertiesPrism:

• non-linear refraction

• affected by temperature

due to influence of

medium density

Grating:

• linear diffraction

• different orders

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Reciprocal dispersion as criteria of line separation

500

750

1000[mm]

diameters of

Rowland circuit

lines/mm

focal length [mm]

3600

500

0,51

2400

750

0,52

1800

1000

0,51reciprocal dispersion

[nm/mm]

center

entrance slit

area for

detectors

grating

3600 grooves/mm grating

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Spark OES Spectrum 130nm – 800nm

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Calculation of results from Calibration Curve

result comparison to previouslymeasured set of calibration samples

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Emission spectrometry is a relative measurement method

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Recalibration, Standardization or Drift correction

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Type Calibration

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Illustration of exaggerated concentration error Δ in a calibration curve where Type calibration correction can be used to improve accuracy.

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Measurement accuracy and reproducibility

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The analytical Process

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Sample taking Sample preparation Chemical analysisSpectrosource Pty Ltd copyright 2019

Type Calibration and measure program

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Material Data Base / Grade Table

double click

• software compares analysis results with

element concentration ranges and

reports grade maches

• virtually unlimited material data entries

• international material standards as well

as customised data base can be loaded

• Specific material data base can be

linked to a measuring program

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Thank you. For more information or feedback contact Glen Thiele

mobile: 0420323577email: info@spectrosource.com.au

• References

• (1) V. Thomsen, Modern Spectrochemical Analysis of Metals: An Introduction for Users of Arc/Spark Instrumentation (ASM International, Materials Park, Ohio, 1996).

• (2) Power Point Presentations – definitions and images: Belec Spectrometrie Opto-Electronik(2012 – 2016).

• (3) Various definitions and images: Wikipedia.

• (4) Melting Spectro Analysis Version 6: G Henderieckx – Gietech BV

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