powerful analytics based on modern...

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Unternehmen der Analytik Jena Gruppe

Powerful Analytics based on Modern Spectrometers

Gerhard SchlemmerAnalytik Jena AG, Konrad- Zuse- Str. 1, 07745 Jena

[email protected]

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Powerful Analytics based on Modern Spectrometers

• Optimizing Analytical Quality

• Absorption: Line oder Spectrum?

• Atomic Fluorescence: simple optics, excellent

S/N: Where are the limits?

• Absorption/ Emission

– Sequential or simultaneous?

• Bio Analytics

– Limitations and chances due to new materials

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Recovery;Calibration

Detector, Optics, Source,

Elektronic, Correktions,

Sample presentation

Long Term Stability

Range of UseDetector, Optics, Source, Elektronics Corrections, Sampel presentation

Detection Limit

Repeatability Time for Measurement

Atomizer, Meas.Volume, Corrections

(Detektor, Optics)

RSD

DL, RSD Working range.

Detector, Optics, Source, Elektronics

Noise

DL

RSD

Working range.

Atomizer, Meas.Volume, Optics, Source

Sensitivity

InfluencesSystem ComponentAnalyt. Parameter

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Absorption:Line oder Spectrum?

Line Source AAS OpticsCzerny- Turner MonochromatorResolution~ 200 pm

Double Echelle-MonochromatorResolution ~ 2 pmBased on „DEMON“ ISAS-Berlin

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Absorption:Line oder Spectrum?

LS AASSource IntensityMn – Triplet:

279, 4817 nm279, 8269 nm280, 1085 nm

0 , 0

0 , 2

0 , 5

0 , 7

1 , 0

2 7 9 , 3 2 7 9 , 4 2 7 9 , 5 2 7 9 , 6 2 7 9 , 7 2 7 9 , 8 2 7 9 , 9 2 8 0 , 0 2 8 0 , 1 2 8 0 , 2 2 8 0 , 3

W e l le n lä n g e ( n m )

Ab

so

rpti

on

CS AASAbsorption spectraMn – Triplet:

279, 4817 nm279, 8269 nm280, 1085 nm

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Spectral window 200 pm

Absorption profile 1-5 pm

....................................................................................

LS

CS

Emission line ~2 pm

Spectral window 200 pm

CCD-Array with a resolution of ~ 2pm/ pixel

Absorption: Linie oder Spektrum?

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Absorption: Line oder Spectrum?

Is a source line really one line?: Emission of a Cd- hollow cathode lamp as a function of the lamp current.

Ref. T. Labatzke, Analytik- Jena,

C. Scholz, D. Mory, LTB, Berlin 2002

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reference pixels

simultaneous

optical double beam

sequential

source drift

reference pixels

Reference spektra

simultaneous

BG correction, sequential(D2 lamp, Zeeman effekt, line reversemethod)

unspecific absorption

reference pixels

simultaneous

lamp modulation

sequential

thermal emission

correction HR-CS- AAScorrection LS-AASsource of error

Corrections required in AAS

Absorption: Line oder Spectrum?

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Example: complex Background close to the analyte line

NO- Structure in the vicinity of 213,857 nm

HR-CSAASA New Way to look at Atomic Absorbance

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Determination of P on PO- Band at 246,400 nm using theC2H2/ Air Flame (Absorbance reading on molecular Band)

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Abs. wave length spectra 3D

Abs. wave length spectra 2D

Gain in information: absorbance becomes 3. dimensional

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Absorption: Line or Spectrum?

• Extended application range: atomic+molecular

• Simultaneous corrections for better accuracy

• Much more information on background– Atomic lines

– Molecular band and fine structure

– Pushing the limits in complex matrices

• Independence of c0/m0 on lamp type, age or fine structur– Opening a new chapter on the way towards absolute

analysis

• Will we finally approach real simultaneous AAS?

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Atomic Fluorescence

System Mercur „Duo“fluorescence and absorption in one system; measurement of mercury vapour in an argon carrier stream

Signalvergleich AFS / AAS

0,00

0,01

0,01

0,02

0,02

0,03

0 5 10 15 20 25 30 35 40

Integrationszeit [ sec. ]

Inte

nsitä

t [ In

ts ]

-0,005

0

0,005

0,01

0,015

0,02

0,025

0,03

Extik

tion

[ E

xt ]

AFS-Signal 1µg/L

AAS-Signal 1µg/L

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AAS vers.AFS

Background Abs.Source driftBackground Abs.

Quenching

Interferences

102,5104Lin. Calib. range

3 ng/L (Hg)0.3 ng/L (Hg)DL

All techniquesCVG onlyApplication

AASAFSParameter

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Simultaneous vers. Sequential Reading ICP- OES

++++Content of info

+++Ruggedness

+++DL

+++Interferences

+++Cost

+++++Working range

++++Speed p. element

++Speed p. sample

ICP- Simult.ICP- SequentialParameter

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Simultaneous vers. Sequential ReadingUV/VIS

+++S/N

Moving partsFixed opticsRuggedness

Selected WLFull illuminationSample

0.5 nm1-2 nmOptical resolution

0.3%T*/0.005%T0.9%T*/0.05%T**Stray light

~3A~2ALin.Calib.Range

Slow 1 minVery fast <<1sSpectra

Sequential (S250)

Simultaneous (S600)

Parameter

* Validation at 198 nm; ** Validation at 220 nm

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Bio AnalyticsLimitations and chances due to new applications

• Chips/cells/ flow system require photons and detection on a spot

• Direct contact with bio- media may require biocompatible materials

• Often extrem cost sensitive parts (disposables)

– Use of lightwave guides-

– Use of fiber- optic sensors-

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Bio Analyticsjust a few examples of light wave

guides/ fiber-optical sensors

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Gesellschaft Deutscher ChemikerFachgruppe Analytische Chemie

Deutscher ArbeitskreisSpektroskopie

DASp: DoktorandentreffenJena, 9-10 Juli 2008

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ESAS 2008Weimar, Sept 28th-Oct 1stThe European Spectroscopy Symposiumwww.esas-symposium.de

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