Results of the 18 th and 19th Needle/LeafInterlaboratory Comparison Tests

Meeting of the Working Group QA/QC in Laboratories

Zagreb/Croatia March 2017

Alfred FÜRST

Overview

• General information about both tests• Main Results• Common methods• Problematic parameters/laboratories• Re-qualification after the 18th Test• Reference samples• Ongoing foliage ringtest program• Enlarge parameter list (heavy metals)

Countries/LaboratoriesInterlaboratory

Comparison TestNumber

of countriesNumber of

laboratories

5th

29 53

6th

26 46

7th

23 43

8th

30 52

9th

28 53

10th

29 54

11th

28 56

12th

30 56

13th

29 60

14th

28 62

15th

28 61

16th

25 57

17th

25 54

18th

25 53

19th

22 45

Participating labs decreasing

• Stop funding of the monitoring program

• Participating only in uneven years -

paralell to the monitoring activities

• 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??

Comparison between 7 th and 19 th

Interlaboratory Comparison TestElement 7 th Test 2004/05 (Sample 1) 19 th Test 2016/17 (Sample 4)

(Unit) Mean Number of Labs Mean Number of Labs

N 17.01 17.17

mg/g 39 38

S 1.09 1.12

mg/g 39 37

P 1.89 1.93

mg/g 41 41

Ca 2.63 2.70

mg/g 41 42

Mg 0.92 0.94

mg/g 41 42

K 5.83 5.82

mg/g 42 42

C 51.61 52.13

g/100g 29 34

Comparison between 7 th and 19 th

Interlaboratory Comparison TestElement 7 th Test 2004/05 (Sample 1) 19 th Test 2016/17 (Sample 4)

(Unit) Mean Number of Labs Mean Number of Labs

Zn 41.73 41.72

µg/g 36 33

Mn 183.6 183.1

µg/g 35 34

Fe 36.81 36.86

µg/g 34 32

Cu 3.13 3.03

µg/g 31 33

Pb 0.21 0.17

µg/g 15 26

Cd 78.63 75.42

ng/g 20 24

B 5.98 5.09

µg/g 21 18

Difficult Samples & Elements

18th Test

1. Beech Leaves� + B � - Pb

2. Pine Branches� + Fe, Cd� - N, S, P, Ca, Mg, K, B

3. Spruce Needles� - Pb

4. Spruce Needles� - Pb

19th Test

1. Spruce Needles� - Pb

2. Spruce Needles� - Pb

3. Spruce Needles� + Zn, Pb, Cd

4. Pine Needles� - Ca, B, Pb

too low content for evaluation

Percentage of non tolerable results in Needle/Leaf samples

0

5

10

15

20%

S P Ca Mg K N

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)

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

Pretreatment methods 2016/17Element

open

digestion

pressure

digestion microwave

dry

ashing pellet

no or other

pretreatment

N 9 29

S 3 7 16 2 9

P 8 7 21 2 3

Ca 9 8 21 2 2

Mg 9 7 22 2 2

K 9 8 21 2 2

C 1 1 32

Zn 3 7 20 2 1

Mn 3 7 21 2 1

Fe 2 6 21 2 1

Cu 3 6 21 2 1

Pb 1 7 18

Cd 1 7 16

B 1 3 13 1

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

Determination methods 2016/17Element

Element-

analyzer

Flame-AAS

& AES Flameless-AAS ICP-AES ICP-MS other

N 29

9 (Kjeldahl)

1 (UV-VIS)

S 7 24 3 3 (X-Ray)

P 28 3

3 (X-Ray)

7 (UV-VIS)

Ca 8 28 3 3 (X-Ray)

Mg 8 28 3 3 (X-Ray)

K 9 27 3 3 (X-Ray)

C 32 1

Zn 1 21 8 3 (X-Ray)

Mn 3 23 5 3 (X-Ray)

Fe 1 23 5 3 (X-Ray)

Cu 1 20 9 3 (X-Ray)

Pb 3 10 13

Cd 4 8 12

B 14 4

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

Element Tolerable 17th

Labtest 18th

Labtest 19th

Labtest

limits 2014/2015 2015/2016 2016/2017

(± %) Non Number of mean values

Non Number ofmeanvalues

Non Number of mean values

tolerable tolerable tolerable

(%) (%) (%)

N 10 2.1 192 7,9 164 4,6 152S 15 9.9 192 6,4 156 7,4 148P 10 14.7 204 15,5 168 15,4 164

Ca 10 17.7 212 9,1 176 11,3 168Mg 10 12.3 212 14,2 176 13,1 168K 10 11.5 208 15,6 180 16,7 168C 5 7.8 180 9,5 148 8,1 136Zn 15 8.1 172 13,5 148 12,1 132Mn 15 3.9 180 6,1 148 8,8 136Fe 20 6.5 168 12,2 148 13,3 128Cu 20 15.7 172 4,2 144 15,2 132Pb 30 7.8 87 16,0 75 7,7 24Cd 30 14.3 112 8,0 112 2,1 96

B 20 5.0 100 11,9 84 13,9 72

+

Compare your results from thelast 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?•„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 thelast 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?•„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/analyticalequipment“

Compare your results from thelast tests - what happend?

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

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

18th Test < <<<<

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

• C is always too low(Element analyzer) – no improvement• Open digestion method & ICP-AES � contamination?• Changes in the laboratory staff? Wrong samples?• „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“

Compare your results from thelast tests - what happend?

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

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

18th Test < <<<<

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

• C is always too low(Element analyzer) – no improvement• Open digestion method & ICP-AES � contamination?• Changes in the laboratory staff? Wrong samples?• „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“

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%

What is a good result?

• % Recovery close to 100% with a smallvariation between the four sample results(= your method is under control)

• Vi (variation between the replicates)– element analyzer (measurement without

extra sample preparation) < 3%– Macro elements (P, K, Ca, Mg, K) < 5%– Micro elements and heavy metals < 10%– Trace elements < 20%

Reasons for Re -Qualificationafter the 18th Needle/Leaf Ringtest

• Technical problem / no servicing of the instrument (5 labs)

• Calibration error (one lab)• Methodical problem / method changed

(one lab)• Missed data submission deadline or got

no samples (one lab)• No dry matter correction (one lab)

Re-Qualification after the19th Needle /Leaf Ringtest

• Is mandatory for all „ICP-Forestslaboratories “ if they plan to:

• Submit monitoring results from thesampling period 2016/17 to the PCC database („growing saison “ 2016)

• Deadline 1 st September 2017

Re-Qualification

• Use in all communications your lab code number

• Use in any case the xls-form for your re-qualification: http://bfw.ac.at/rz/bfwcms2.web?dok=7830

• Submit all printouts. calibration. dilution factors .… (= I should be able to recalculate your results!)

• What was the reason (or your opinion) for missing the qualification?

• Think on m easures to avoid errors in future!

FFCC offers reference materials

• Spruce needles A• Maple leaves A • Litterfall (beech leaves)• Pine needles (Pinus nigra)• Spruce needles B (+heavy metals )

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

Element N/L Unit Mean SR

N 140/35 mg/g 14.20 0.376

S 136/34 mg/g 0.94 0.047

P 156/39 mg/g 2.01 0.121

Ca 160/40 mg/g 5.83 0.339

Mg 156/39 mg/g 1.07 0.058

K 156/39 mg/g 7.28 0.413

Zn 127/32 µg/g 32.70 2.574

Mn 128/32 µg/g 359.3 22.689

Fe 124/31 µg/g 73.73 8.568

Cu 128/32 µg/g 3.16 0.441

Pb 56/14 µg/g 0.08 0.034

Cd 76/19 ng/g 28.14 3.283

B 68/17 µg/g 12.06 1.320

C 135/34 g/100g 51.98 1.152

As 32/8 ng/g 20.53 4.957

Co 64/16 µg/g 0.29 0.020

Cr 88/22 µg/g 4.24 0.637

Hg 52/13 ng/g 28.27 6.501

Mo 32/8 ng/g 291.6 31.109

Ni 90/23 µg/g 2.26 0.268

Tl 24/6 ng/g 5.12 0.896

V 36/9 µg/g 0.063 0.008

Spruce needles B New

20th Needle /Leaf Interlaboratory Test 2017/18

http://bfw.ac.at/ws/ring_nadel.login

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

Enlarge parameter list

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

Element commonMethod

Number oflabs

„low“content

„high“content

Arsenic ICP-MS 13 41 ng/g79.6-119.4%

127 ng/g84.2-110.3%

Cobalt ICP-MS/(ICP-AES)

17 0.066µg/g67.1-130.1%

0.47µg/g75.4-113.3%

Chromium ICP-AES 23 0.863µg/g80.5-139.3%

4.24µg/g70.9-129.1%

Mercury ICP-MS / Element analyzer

14 31.5ng/g89.8-109.8%

70.6ng/g86.9-114.3%

Nickel ICP-AES 23 0.831µg/g80.1-120.9%

5.36µg/g80.8-115.6%

Element commonMethod

Number oflabs

„low“content

„high“content

Cadmium ICP-MS/GF-AAS

24 28.1ng/g85.3-127.8%

294ng/g81.8-117.7%

Lead ICP-MS/GF-AAS

26 0.43µg/g61.1-142.9%

27.1µg/g59.7-129.6%

Element commonMethod

Number oflabs

„low“content

„high“content

Arsenic ICP-MS 13 41 ng/g79.6-119.4%

127 ng/g84.2-110.3%

Cobalt ICP-MS/(ICP-AES)

17 0.066µg/g67.1-130.1%

0.47µg/g75.4-113.3%

Chromium ICP-AES 23 0.863µg/g80.5-139.3%

4.24µg/g70.9-129.1%

Mercury ICP-MS / Element analyzer

14 31.5ng/g89.8-109.8%

70.6ng/g86.9-114.3%

Nickel ICP-AES 23 0.831µg/g80.1-120.9%

5.36µg/g80.8-115.6%

Element commonMethod

Number oflabs

„low“content

„high“content

Cadmium ICP-MS/GF-AAS

24 28.1ng/g85.3-127.8%

294ng/g81.8-117.7%

Lead ICP-MS/GF-AAS

26 0.43µg/g61.1-142.9%

27.1µg/g59.7-129.6%

Thank you for your attention!