Alfred FÜRST

Forest Foliage Co-ordinating Centre

Pallanza/Italy 7.9. – 8.9.2017

ICP-FORESTS - 6th Meeting of the Heads of the Laboratories

Results of the 18th and 19th Needle/Leaf Interlaboratory Comparison Tests

Overview

General information about both tests

Main results

Common methods

Problematic parameters / laboratories which failed in both tests

Re-qualification 18th and 19th test

Reference samples

Enlarge parameter list (heavy metals)

Ongoing foliage ringtest program

Database update with new parameters

Needle/Leaf Interlaboratory Comparison tests

Countries/Laboratories

Participating labs decreasing

Stop funding of the monitoring program

Participating only in uneven years - paralell to the monitoring

activities (20th, 18th, 16th Test, ….)

Closing and/or merging of labs

Costs of the ringtest…

240 € are too expensive?

= 7 l nitric acid 65%

= 100 ml multielement standard

= one PTFE vessel for microwave digestion

= 4 working hours of a lab worker

And how expensive are wrong results??

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Comparison between 7th and 19th Test

Comparison between 7th and 19th Test

Difficult Samples & Elements

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Percentage of non tolerable results in

Needle/Leaf samples

%

Labs failed with the same element/s

in both tests

Germany A59 (C)

Germany A79 (Mg)

Germany A80 (Zn)

ICP-Forests lab - Croatia A62 (Ca, Mg)

ICP-Forests lab - Spain F33 (Fe)

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Re-qualification process

Please, ask your colleagues if they have similar problems!

What influences data quality? Results of the questionaire:

Laboratory accreditation

Higher number of analyzed samples/a

Control charts

Staff trained on the method/matrix

More than one ringtest participations/a

Pre-treatment methods 2016/17

Changes in pre-treatment methods

from 2006 till 2017

N: open digestion no digestion (element analyzers)

Dry ashing open digestion (P, K, Ca, Mg, Mn)

or to microwave

Pressured digestion microwave

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Microwave digestion & Temperature

Target temperature should be 200°C for 20 minutes

In reality:

max. temperature:

111-168°C for oneminute!

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Determination methods 2016/17

Changes in determination methods

from 2006 till 2017

N: „Kjeldahl method“ Element analyzers

Flame-AAS ICP-AES

Flameless AAS ICP-MS

ICP-AES ICP-MS

Training-course needed!

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ICP-AES / plant samples

Use standards with similar concentration like your samples

Use matrix adapted standards with similar acid & element

concentrations

Use enough standards (>3) depending on the selected

correlation function (linear, quadratic, regressed, weighted)

Check the calibration with an seperate prepared independent

sample/standard solution

On dual view systems: use radial view for Ca, (Mg), K - all other

elements can be measured in axial view with higher

sensitivity

Calibration ICP-AES / plant samples

„Normal conc. range“ of the sample in mg/l

„Check Standard“

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There are more things in heaven

and earth than you are dreamed of…

in ICP measurement too…!

Training-course needed!

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Drying of standard materials for CNS

element analyzers

Reason was a not (enough) dried

coal standard material…

Compare your results from the last

tests - what happend?N S P Ca Mg K C Zn Mn Fe Cu Pb Cd B

16th Test >

17th Test >> >

18th Test >> > <>> <> <>>

19th Test > << < < < < >>>> < <<<<

C, N („other element analyzer“)

„Pressure digestion / ICP-MS“

Always problems with Fe! What is with B in the last test?

Compare your results from the last

tests - what happend?N S P Ca Mg K C Zn Mn Fe Cu Pb Cd B

16th Test >

17th Test >> >

18th Test >> > <>> <> <>>

19th Test > << < < < < >>>> < <<<<

„Is no accredited testing laboratory“

„Lab uses a mean, a range and a blank control chart“

and check nothing?

„100-500 plant samples/a“

„Good trained staff on the method/analytical equipment“

Compare your results from the last

tests - what happend?

C is always too low („Element analyzer“) – no improvement

„Open digestion method & ICP-AES“ contamination?

Changes in the laboratory staff? Wrong samples?

N S P Ca Mg K C Zn Mn Fe Cu Pb Cd B

17th Test > >> >> <<< >>> >>> > >>>> >

18th Test < <<<<

19th Test << >>>> >>>> >>>> >>>> >>>> <<<< >>>> >>>> >>>> >>>> >>>>

Compare your results from the last

tests - what happend?

„No accredited testing laboratory“

„Lab uses a mean chart and blank chart“ and check nothing?

„1000-5000 samples/a“ 50-250 correct analyzed samples!

„Good trained staff on the method/analytical equipment“

N S P Ca Mg K C Zn Mn Fe Cu Pb Cd B

17th Test > >> >> <<< >>> >>> > >>>> >

18th Test < <<<<

19th Test << >>>> >>>> >>>> >>>> >>>> <<<< >>>> >>>> >>>> >>>> >>>>

What is a good result?

Accuracy of the mean & precision

% Recovery = 97.79 – 99.93% Vi = 0.60-1.17%

% Recovery = 86.22 – 131.2% Vi = 2.97-7.89%

This is a good result!

% Recovery close to 100% with a small variation between the four

sample results and without influence of the sample concentration

(= your method is under control)

Vi (variation between the four replicates)

o element analyzer (measurement without extra sample preparation) < 3%

o Macro elements (P, K, Ca, Mg, K) < 5%

o Micro elements and heavy metals < 10%

o Trace elements < 20%

Reasons for Re-Qualification

Technical problem / no servicing of the instrument (6 labs)

Calibration error (3 labs)

Methodical problem / method changed (4 labs)

Missed data submission deadline or got no samples (one lab)

Calculation error ( 2 lab)

No dry matter correction (2 labs)

FFCC offers reference materials

Maple leaves A

Litterfall (beech leaves)

Pine needles (Pinus nigra)

Spruce needles B (+heavy metals)

http://bfw.ac.at/rz/bfwcms2.web?dok=5146

www.ffcc.at

Spruce needles B New

Statistical evaluation for heavy metals

Heavy metals Heavy metals

Enlarge parameter list

Use of multielement methods (ICP-AES, ICP-MS)

no additional costs/time

Ringtest participation (> 10 laboratories)

Repetitious accuracy

New parameter up from the 20th Test

Above the element symbol you can see the number of participants in the last test.

Evaluation limits

Finalized on the EP Meeting Foliage and Litterfall in Zagreb/TFM Luxembourg 2017

Parameter list / 20th Test

Ringtest samples / 20th Test

Sample 1 - Birch leaves (Austria)

Sample 2 - Spruce needles (Germany)

Sample 3 - Spruce needles (Austria)

Sample 4 - Pine cones (Austria)

Ringtest material is needed – especially from broadleaves trees

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Database update – FOM/LFM Forms

FOM - Sampling and Analysis of Needles and Leaves

LFM - Sampling and Analysis of Litterfall

Arsenic

Cobalt

Chromium

Mercury

Nickel

Database update - d_parameter_lfCODE DESCRIPTION FROM_YEAR TO_YEAR UNIT

Al Aluminium 2009 2007 mg/g

B Bor 2009 µg/g

C Carbon 2009 g/100g

Ca Calcium 2009 mg/g

Cd Cadmium 2009 ng/g

Cu Copper 2009 µg/g

Fe Iron 2009 µg/g

K Potassium 2009 mg/g

Mg Magnesium 2009 mg/g

Mn Manganese 2009 µg/g

N Nitrogen 2009 mg/g

Na Sodium 2009 2007 mg/g

P Phophor 2009 mg/g

Pb Lead 2009 µg/g

S Sulphur 2009 mg/g

Zn Zinc 2009 µg/g

As Arsenic 2017 ng/g

Co Cobalt 2017 µg/g

Cr Chromium 2017 µg/g

Hg Mercury 2017 ng/g

Ni Nickel 2017 µg/g

Thank you for your attention!