High Resolution Continuum Source AAS -Atomic Absorption Spectroscopy With Only

(1)

High Resolution Continuum Source AAS

-Atomic Absorption Spectroscopy with

only one light source –

the only innovation of the XXI century

in Atomic Absorption and a new

challenge for Environmental Analysis

(2)

_{One light source for all elements} _{Real multi element AAS}

_{Simultaneous background correction} _{Recording of reference spectra}

_{More spectral information} _{Wider working range}

_{Better detection limits}

HR-CS AAS - it´s something in between AAS and ICP OES !!

HR Continuum Source AAS –

HR-CS AAS

It is still routine AAS

(3)

1. Radiation source ⇒

⇒

Xenon – short arc lamp/

HCL, EDL,

boosted HCL

2. Atomizer

⇒

identical atomizer for flame technique

3. Monochromator ⇒

⇒

High resolution /

low resolution

> 1:140000

1:10000

4. Detector

⇒

CCD array detector/

single spot

detector (PMT)

5. Software

⇒

Aspect CS/

WinAAS

(4)

To many limitations of traditional LS flame AAS

No flexibility , only defined lines

Less information - interferences, no vicinity

But

robustness, simple to operate, fastness, low costs

(5)

_{HR- CSAAS brings a new dimension of capabilities to AAS}

_{All flame elements are permanently available from one source}

_{Routine flame applications can be run as simple as in LS AAS}

_{Detection limits are improved}

_{All AAS correction modes are simultaneous and permanent}

_{Additional sources of noise can be understood and corrected for}

_{The method is not limited to atomic lines}

_{Complex determinations due to spectral overlap can be corrected with}

reference spectra

_{There is space for research in flame AAS}

... – or basis of a new generation in atomic spectrometry

the HR-CS AAS?

(6)

The most important reasons to buy an contrAA !

1. SIMPLY THE BEST !!!

2. AAS with 1 Lamp only!

3. The total Flexibility! Flexibel and simple in one system!

4. Fastness! Immediately ready to measure!

5. Applications with complex sample matrix!

6. New dimension of information

7. Only Alternative to ICP

(7)

1. SIMPLY THE BEST !!!

The most innovative and state-of-the-art instrument in field

of AAS

-

Prestige

-

Status symbol! UNIQUE!

-

Image of the customers

--

Global Players

-

But also scientific image:

publications, research, projects...

contrAA 700

(8)

2. AAS with 1 Lamp only!

Replacement of

up to 60 different HCL´s

BGC lamp (deuterium lamp)

No lamp adjustment

No loss of energy with second light source

No loss of time regarding heating time of

the lamp

No problems with aging of the lamp

(line broadening, sensitivity loss...)

HR-CS AAS

Xenon short arc lamp as continuum radiator

ready for measuring:

- each element on - each wavelength

(9)

Comparison of intensity of different light sources

A Xenon-short arc lamp, XBO 301, 300 W, (GLE Berlin), „Hot - Spot“ - Mode B Xenon lamp, L 2479, 300 W, (HAMAMATSU), diffuse mode

C D2 - Lamp, MDO 620, 30 W, (HERAEUS)

Source: „High-resolution continuum source AAS“ Welz,Becker-Roß,Florek,Heitmann

2 0 0 2 5 0 3 0 0 3 5 0 4 0 0 1 E - 3 0 . 0 1 0 . 1 1 1 0 1 0 0 A B C R a d ia n c e [ W / c m 2 s r n m ] W a v e le n g t h [ n m ] Ag Au Pb Cd Pb Zn As

(10)

Lamp Cost

A Line source AAS needs a Deuterium Lamp and for each element a hollow cathode lamp

For some elements (e. g. As, Se ) most manufacturer recommend EDL`s or Superlamps

The contrAA needs only one lamp for background correction and all elements

550 D2 Lamp

2100 - 2200 Xenon lamp contrAA

1800 Power supply for superlamp

940 Superlamp

350 HCL (average)

Line Source AAS contrAA

(11)

3. The total Flexibility!

Flexibel and simple in one system!

No limitation of elements

No limitations of lines

Molecular bands and

Non metals (S,P...)

Minimum interferences

Simple to operate

(12)

_{seldom or rare requested analysed elements}

_{exit window of HCL (UV or VIS permeable)}

Cu - HCL ⇒ 217,9 nm, W - HCL ⇒ 255,1 nm

_{element interferences do not disturb the line selection} _{atomic absorption using element lines or molecular bands}

possible

analytical purpose decides element and line selection

Continuum source – provides more flexibility

All absorption and molecular lines are available

independent of:

(13)

LS AAS _{use of most sensitive line}

HR-CS AAS _{no limitations in line choice} BUT:

_{Sometimes not the best SNR} _{Non linear calibration curve}

_{Use of less sensitive secundary lines} _{No problems with interferences}

(14)

all absorption lines are available

-independent if seldom or rare requested elements

Continuum source – provides more flexibility

Xenon lamp is covered in a safety lamp box

⇒

provides emission spectrum of

the complete AAS relevant spectral

range (190 – 900 nm)

(15)

more flexibility…independent line choice

Gd in organic matrix as main component

Problem:

_{Extremly seldom, no standard application}

_{High concentrated samples}

_{No high concentrated standards available}

_{No lamp available}

(16)

all absorption lines are available

-independent if seldom or rare requested elements

Gd in organic matrix - all absorption lines are available

_{Gd 407.870 nm}

_{Gd 368.4 nm}

Standard calibration: 0.25 - 1.0 mg/ mL Gd

(17)

Continuum source – provides more flexibility

_{determination of}

_phosphorus

_{using PO – molecular bands}

(e.g. 246,40 nm, 247,62 nm, 247,78 nm, 324,62 nm, 327,04 nm)

_{determination of}

_sulfur

_{using CS – molecular bands}

(e.g. 257,59 nm, 258,06 nm)

_{determination of}

_fluorine

_{using AlF - molecular bands}

(e.g. 227,47 nm)

_{determination of}

_chlorine

_{using AlCl or GaCl - molecular bands}

(e.g. 261,44 nm, 249,06 nm)

absorption and molecular lines

for analytical use

(18)

Determination of P flame in defatting solvent 1-7 g/L P in C₂H₂/ air 7 pixel c₀ = 0,29 g/L LOD = 22 mg/L 0,5 g/L P

Availability of molecular bands

PO- band at 324,619 nm C₂H₂/ air - flame

(19)

Determination of P flame in defatting solvent

Availability of molecular bands

Element Sample DF Concentration [g/L] RSD [%] P 324.619 nm Degreasing by boiling (A) 5 _{3.58 ±}_±_±± 0.30 0.9 2 3.51 ±±±± 0.12 0.8 1 _{3.59 ±}_±_±± 0.07 1.4 Degreasing by electricity (B) 5 _{5.61 ±}_±_±± 0.29 0.9 2 5.46 ±±±± 0.13 2.4 1 4.92 ±±±± 0.07 0.8 (A) (B)

(20)

wine 1 C₀ (g/L) 0,355 R2 _0,9993 NWG (g/L) 0,071 Determination of S in wine wine 1+ 2000 ppm S

Availability of molecular bands

CS- band at 258,054 nm C₂H₂/ N₂O - flame

(21)

Molecular bands could be used for determination of

elements which are normally not detectable with atomic absorption

sample DF S- conc.

[mg/L]

RSD [%]

Angelo Cremaschi 2003 Cabernet Merlot (13,5% Vol.)

1,043 155 9,2

Domaine de Gazel 2000 Minervois (12,0% Vol.)

1,043 ₁₆₅ _7,6

Cabernet Sauvignon 2004 Récolte (12,0% Vol.)

1,043 ₁₄₈ ₁₁

Señorio del Aguila 1998 Reserva (13,0% Vol.)

1,043 ₂₈₈ ₁₁

Determination of S in wine

(22)

Simple….because it is a well known and well described

method!

New technique but not new!

Described methods(cookbook) are useable.

Comparable with other systems and results.

Simple analysis

(23)

4. Fastness

Of measurement

real sequential multi element analysis

Of method development and parameter optimization

you can see what you do!

Immediately ready to measure!

No delay time with flushing and rinsing the system

No delay with preheating time of lamps

(24)

Real Multielement Analysis

Single element method

-calibration Cu Pb Fe Ni Zn sample 1 sample 2 sample 3 …

LS AAS

calibration Cu Pb Fe Ni Zn sample 1 sample 2 sample 3 …

CS AAS

Sequential multi element analysis

_{Schema ändern-sieht Varian zu ähnlich!!}

(25)

(26)

Determination of 7 elements in high concentrated sugar

solution

_{Elements to be analyzed, Ca, Mg, Na, K, Cu, Fe and Pb}

_{Elements are present in very different concentration ranges} _{High sugar concentration leads to clogging of the burner head} _{Elements require different sample preparation}

_{Analysis very time consuming}

Problems of a LS AAS user

All problems can be solved using CS AAS

Sample is used for fermentation purposes, dark brown very viscose solution

(27)

Sample preparation

LS AAS

Sample stock solution: 0.5 g sample + 2 mL HCl dilution up to 100 mL

Ca: 2 mL stock solution dilute with 0.1% KCl up to 50 mL

K: 0.5 mL stock solution dilute with 0.1% LaCl3 up to 100 mL

Mg: 2 mL stock solution dilute with 0.1% LaCl3 up to 50 mL

Fe: 10 mL stock solution dilute with 0.2% CaCl2 up to 50 mL

Na: 0.5 g sample + 2 mL HCl dilute with 0.1% KCl up to 50 mL

Pb: 0.5 g sample + 1 mL HCl dilute with 0.1% HNO3 up to 50 mL

Cu: 5.0 g sample + 2 mL HCl diluted up to 100 mL (Solution X) 10 mL solution X diluted with 1% HNO3 up to 50 mL

(28)

Sample preparation

CS AAS

Uniform sample preparation for all elements

(29)

Method parameter

Alternative wave lengths match to different element concentrations. Some wave lengths are not available with standard HCLs.

(30)

Method parameter

Different numbers of detectors (pixels) match to the element concentrations.

(31)

Multi element calibration

Pb 1-5 mg/L Na 5-20 mg/L

Mg 10-40 mg/L

(32)

Element spectrum

Ca Cu Fe

(33)

Multi element results

Element Concentration mg/kg RSD % Ca 4205 ± 38 1.2 Mg 1126 ± 18 0.4 K 74880 ± 288 0.2 Na 182 ± 6 0.7 Fe 179 ± 4 1.1 Cu 8.9 ± 0.1 0.4 Pb 0.82 ± 0.07 4.2

(34)

Startup Time

The contrAA is ready to run samples within 5 minutes after the flame is ignited

_{Very fast analytical results} _{Very low cost for gas}

The ICP is ready to run samples 40 to 60 minutes after the plasma is ignited

_{It takes at least 40 minutes before you get the first analytical results} _{The argon gas consumption is between 1200 and 1800 liter before you}

(35)

5. Complicated applications_samples with

complex matrizes

(36)

Bernhard Welz, Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis – SC, Brasil

In case of a spectral interference, we can see only the result, but not the reason –

therefore an optimization of parameters to avoid the spectral interferences is difficult.

LS AAS –

Visible is the Absorption vs. time within the small emission spectral range from the line source

(37)

Bernhard Welz, Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis – SC, Brasil

Spectral information Graphite furnace - LS AAS

HR

HR--CS AAS CS AAS –– therethere isis a 3tha 3th DimensionDimension, , itit meansmeans wewe cancan seesee muchmuch more

Background correction par excellance

wavelength: 276.787 nm; sample: 10 µl i.e. 0.1 mg PACS-2 marine sediment SRM (NRC Canada); pyrolysis: 300°C; atomization: 1650°C; resolution ≈ 2 pm per pixel

before BB correction

after BB correction

(1. correction of broad-band effects)

(39)

“true” analyte signal

before least-squares correction

wavelength: 276.787 nm; sample: 10 µl i.e. 0.1 mg PACS-2 marine sediment SRM (NRC Canada); pyrolysis: 300°C; atomization: 1650°C; resolution ≈ 2 pm per pixel

(2. correction of molecular background)

(40)

reference pixels

simultaneous

optical double beam

sequential lamp drift reference pixels reference spectrum simultaneous BG correction, sequential (D2 lamp,

Zeeman effect, reverse line method) unspecific absorption reference pixels simultaneous Lamp modulation sequential thermal emission Correction CS- AAS Correction LS- AAS Source of Error

(41)

What should be corrected ?

_{structured background}

- spektral interferences with other atom lines

- moleculare absorptions

_{broad-band background}

- streyligth from particels

- thermal emission

_{instrumental influences}

- Intensity drift of light source

- thermal drift

- detector failer

(42)

Background Correction - simultaneously

- no loss of analysis time - spectral resolution

Effects are directly readable

- Structured background - Intensity drift

- Continuous weakening - Emission

(43)

Ni: 232,003 nm Fe: 232,036 nm Ni: 232,140 nm

Determination of Ni in grass flour

spectral band wide: 1,95 pm/ pixel spectral vicinity: 0,39 nm

Ni Fe

sample

Ni

Monochromator – minimization of spectral interferences

Warum misst man einmal mehr und manchmal weniger Bei diesen Störungen???

(44)

standard 0,4 mg/L Ni 5,0 mg/L Fe Ni: 232,003 nm Fe: 232,036 nm Ni: 232,140 nm

Determination of Ni in grass flour

sample

spectral interferences become visible but do not disturb the accuracy

background correction error with D₂

(45)

Determination of Cu, Ni, Fe in galvanic bath

expected concentration: (r = 1,2 kg/L) Cu 30 – 40 g/Kg Ni 2 g/Kg

Fe 10 g/kg

Line selection defined by analytical task

Cu 244,164 nm Ni 231,234 nm Fe 303,739 nm dilution:

factor 200

+

(46)

spectral band wide: 2,1 pm/ pixel spectral vicinity: 0,11 nm

Cu: 324,754 nm Ni: 324,846 nm

Determination of Cu in Ni- galvanic bath

absorption CS AAS: 0,089 Abs absorption LS AAS: 0,057 Abs D₂ – overcorrection: error -36%

More spectral information

about complex or unknown sample

(47)

6. New dimension of information

3dimensional information/Spectra

Information about the line vicinity

(48)

New dimension of information content

Int. wave length spectra Abs. wave length spectra 2D _{Abs. wave length spectra 3D}

More information than LS AAS

- Easy method development - Results easy to evaluate

(49)

Detector – provides more information

UV- sensitive linear array detector (CCD)

„Back Thinned” CCD chip

_{High quantum efficiency} _{High UV-sensitivity}

_{588 pixel}

_{each pixel as an individual detector}

instead of:

_{exit slit for LS AAS}

_{photomultiplier tube (PMT)}

New detector technology for AAS

guarantees best signal to noise ratio

and more information content

(50)

Detector – provides more information

Hydride technique - advanced information content for transient

signals

As signal – 1 µg/L

continuous hydride mode

As

easy

error detection

improves accuracy

eaier method development

Time resolved absorbance

Sample cup became empty

⇒

_{Air molecular absorption}

Time and wavelength resolved absorbance

(51)

7. Cost effective and only alternative to ICP

Costs – Time – Manpower – Experience!

No argon neccessary

Higher purchasing and maintance costs

Better experience necessary

(52)

Installation and Uptime

It takes 2 to 3 hours to install a Flame AAS! It takes 2 to 3 days to install an ICP-OES!

Uptime ( time between service calls) is much higher for an AAS instrument Compare the maintance costs ICP – AAS!