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Results of the 20th and 21st Needle/LeafResults of the 20th and 21st Needle/Leaf Interlaboratory Comparison Tests
Alfred FÜRST
Brussels/Belgium 27.03.2019
ICP-FORESTS - Combined Expert Panel Meeting
Overview
G l i f ti b t b th t tGeneral information about both testsCommon methodsSelected resultsProblematic parameters / laboratories which failed in both testsRe-qualification after 20th and 21st testReference samples for method validationReference samples for method validationMeasures for checking data quality (control charts, ring tests)Ongoing foliage ringtest program 2019/2020Urgent request for new ringtest sample material!Urgent request for new ringtest sample material!
Needle/Leaf Interlaboratory Comparison tests
Countries/Laboratories(Level II - foliage samping in uneven years)
Test Year Number of countries
Number of laboratories
10th
2007/08 29 54
( g p g y )
11th
2008/09 28 56
12th
2009/10 30 56
13th
2010/11 29 60th
14th
2011/12 28 62
15th
2012/13 28 61
16th
2013/14 25 57
17th
2014/15 25 5417 2014/15 25 54
18th
2015/16 25 53
19th
2016/17 22 45
20th
2017/18 23 4820 2017/18 23 48
21st
2018/19 24 52
+
Difficult Samples & Concentrations
+
Evaluation procedure Non-tolerable results76 sample/parameter combinations per test
20%
]
resultsp p p
s [8
0-12
le L
imits
Target value: Outlier free mean [51.77 ng/g] Tole
rabl
g [ g g] T
Max. acceptable limit of quantification [10 ng/g]+
Percentage of non-tolerable results
+
Pre-treatment methods 2018/19
Elementanalyzer
Elementanalyzer
Elementanalyzer
Elementanalyzer
Determination methods 2018/19
Kjeldahl
Photometry
Pre-treatment / Determination methods
1 Microwave digestion ICP AES or ICP MS1. Microwave digestion – ICP-AES or ICP-MS
2. Pressure digestion – ICP-AES or ICP-MS
3 N t t t El t l (C N S H )3. No pretreatment – Element analyzer (C, N, S, Hg)
4. Open digestion – Flame-AAS
5. Open digestion – Kjeldahl (N), Phosphorous (UV/VIS)
6. No pretreatment – X-Ray methods
Comparison between 12th and 21st TestElement 12
thInterlaboratory Comparison Test 2009/10
(Sample 3) ‐ Bears garlic
21stInterlaboratory Comparison Test 2018/19
(Sample 1) ‐ Bears garlic (Unit) Mean Participating labs Mean Participating labs
N 49.64 49.85mg/g 53 45
S 11.66 11.30mg/g 50 43
P 3.80 3.85/ 53 46mg/g 53 46
Ca 5.86 5.81mg/g 54 46
Mg 2.20 2.18mg/g 54 47g/g
K 25.16 25.63mg/g 54 47
C 47.73 48.21g/100g 47 42
Zn 31.84 31.47μg/g 43 38
Mn 56.15 55.93μg/g 44 39
Comparison between 12th and 21st TestElement 12
thInterlaboratory Comparison Test 2009/10
(Sample 3) ‐ Bears garlic
21stInterlaboratory Comparison Test 2018/19
(Sample 1) ‐ Bears garlic (Unit) Mean Participating labs Mean Participating labs
Fe 144.57 141.75μg/g 42 35
Cu 9.11 9.11μg/g 40 37
Pb 0.28 0.25/ 30 28μg/g 30 28
Cd 61.22 66.11ng/g 28 29
B 17.03 16.92μg/g 23 23μg/g 3 3
As 30.40 36.81ng/g 2 14
Cr 1.06 1.05μg/g 10 23
Co 0.049 0.046μg/g 7 21
Hg 8.06 7.62ng/g 7 16 +
Parameters / Participating labs
+
New Parameters / Participating labs
NitrogenTest non tolerable results [%]
15th Test 6.016th Test 3 116th Test 3.117th Test 2.118th Test 7.919th Test 4.620th Test 3.721 t T t 16 121st Test 16.1
Nitrogen results in the 21st Test
Method passed failed % failedDA01: N analyzer >100mg 64 12 15 8
Sample results
DA01: N analyzer >100mg 64 12 15.8DA02: N analyzer <100mg + extra milling 46 6 11.5DZ02: Kjeldahl method 21 11 34.4DA99: Other Element analyzer method 4 ‐ 0%DB01: AAS‐flame technique (C2H2/Air) 4 ‐ 0%DB08: ICP‐AES without Ultrasonic 4 ‐ 0%nebulisationDF08: Other Potentiometric titration 4 ‐ 0%DZ99: Detection method not in this list 4 ‐ 0%DZ99: Detection method not in this list 4 0%
Nitrogen (Kjeldahl method)
Laboratories: A43, A88 an S22
Methodical problems!
o Digestion not complete (which catalyst?)o Contaminationo …….o Wrong units (A88)
Method validation with different types ofMethod validation with different types ofreference materials
Nitrogen (element analyzer)
Laboratories: A56, A57, A59, abo a o es 56, 5 , 59,A62 and A85
Calibration error!
Method validation with reference material
SulphurTest non tolerable results [%]15th 13.916th 14 816th 14.817th 9.918th 6.419th 7.420th 16.721st 16 921st 16.9
Sulphur results in the 21st Testh d d f l d f l dMethod passed failed % failed
DA01: Macro Elemental‐analyzers for C, N or S for solids (Sample > 100mg)
27 9 25.0( p g)
DA02: Macro Elemental‐analyzers for C, N or S for solids (Sample < 100mg)&milling step
3 1 25.0
DA99: Other Element analyzer method 3 1 25 0DA99: Other Element analyzer method 3 1 25.0
DB08: ICP‐AES without Ultrasonic nebulisation 89 7 7.3
DB09: ICP‐AES with Ultrasonic nebulisation 4 ‐ 0.0
DB10: ICP‐MS 6 6 50.0
DB99: Other Atomic Absorption or Emission Spectroscopy method
2 2 50.0p pyDD02: X‐ray methods 7 1 31.3
DE01: UV‐VIS‐spectrophotometry‐technique 2 2 50.0
Relative abundance of Sulphur and possible interferences in ICP MSpossible interferences in ICP–MS
R l tiIsotope
Relative abundance (%) m/z Possible interferences
32S 95.018 32 16O2, 14N18O, 15N17O, 31P1H33S 0.760 33 16O17O, 32S1H34S 4.215 34 17O2, 16O18O, 33S1H36S 0.014 36 18O2, 35Cl1H, 36Ar
Sulphur with ICP-MS
Problematic element for ICP-MS
Diatomic interferences with N, O and Ar on prominent isotope
masses
“Best” is to determine 32S16O on mass 48 in an oxidizing plasma
Special equipment like collision cells and reactive gases are Spec a equ p e t e co s o ce s a d eact e gases a e
useful
Best solution is to change the method (ICP-AES) Best solution is to change the method (ICP-AES)
Calcium in the 21st Test
Method passed failed % failed
fl h i ( / i )
Sample results
DB01: AAS‐flame technique (C2H2/Air) 12 8 40.0
DB02: AAS‐flame technique (C2H2/N2O) 4 ‐ 0.0
DB08: ICP‐AES without Ultrasonic nebulisation 108 8 6.9DB08: ICP AES without Ultrasonic nebulisation 108 8 6.9
DB09: ICP‐AES with Ultrasonic nebulisation 5 3 37.5
DB10: ICP‐MS 11 5 31.3
DD01/DD02: X‐ray methods 11 5 31.3
DA01:Macro Elemental‐analyzers for C, N or S for solids (Sample > 100mg)
4 ‐ 0.0for solids (Sample > 100mg)
Calcium
DB01: AAS‐flame technique (C2H2/Air): o Buffer against P & Si interferences (La or EDTA)o Buffer against P & Si interferences (La, or EDTA)
o Matrix adapted Standards (especially the acid mixture & concentration)
DB09 & DB10: ICP‐AES with Ultrasonic nebulisation & ICP‐DB09 & DB10: ICP‐AES with Ultrasonic nebulisation & ICP‐MS – too sensitive!
Best choice: DB08: ICP‐AES without Ultrasonic nebulisation
Arsenic Percentage ofnon tolerable
res ltsresults
Higher Concentrations better resultsLabs with too high LOQ failed
+
Arsenic results in the 21st Test
Method passed failed % failed
DB08: ICP AES without Ultrasonic nebulisation 2 10 83 3
Sample results
DB08: ICP‐AES without Ultrasonic nebulisation 2 10 83.3
DB10: ICP‐MS 38 2 5.0
DB99: Other Atomic Absorption or Emission 4 0 0DB99: Other Atomic Absorption or Emission Spectroscopy method
4 ‐ 0.0
Only the ICP-MS method is recommended
+
Mercury Percentage ofnon tolerable
res ltsresults
Really good results!
+
Mercury results in the 21st Test
Method passed failed % failed
DA05: Hg Analyzer 27 0 0
Sample results
DA05: Hg‐Analyzer 27 ‐ 0.0
DB03: AAS‐cold vapor technique 4 2 33.3
DB04: AAS hydride technique 2 1 33 3DB04: AAS‐hydride technique 2 1 33.3
DB08: ICP‐AES without Ultrasonic nebulisation 3 ‐ 0.0
DB10 ICP MS 9 0 0DB10: ICP‐MS 9 ‐ 0.0
Really good results!
+
With different methods (Mercury analyzer, AAS hydride, AAS cold vapor, ICP-MS, ICP-AES)!
Low concentrations
Changes in the ranking of these „bad“ labsfrom the 20th to the 21st testfrom the 20 to the 21 test
F21 F09 A45A43A88F24F24A56A62
ICP-Forests laboratory
Reasons for Re-Qualificationafter the 20th Needle/Leaf Ringtestafter the 20th Needle/Leaf Ringtest
1 T h i l bl (4 l b )1. Technical problem (4 labs)2. Methodical problem / method changed (4 labs)3. Calibration error (2 labs)4. Contamination (2 labs)5. LOQ “adjusted”? (2 labs)6. Missed data submission deadline or got no samples (one lab)6. Missed data submission deadline or got no samples (one lab)7. Transcription error (one lab)8. Fault of a labworker (one lab)9 No error found (one lab)9. No error found (one lab)
Labs failed with the same element/s in both testsin both testsRussia - A39 (As),
Germany - A56 (C),
Denmark - A60 (S)Denmark A60 (S),
Croatia - A62 (Ca),
Germany - A82 (K),
Germany - F07 (As, Cr), y ( , ),
Hungary - F21 (Ca) ICP-Forests laboratory
What happend in former tests?
Ring test N S P Ca Mg K Cg g
17th Test <>> < <
18th Test < <<<> <>> <<> <>>
19th Test > <<<< >>>> <<<
20th Test < <> <<<< <<< <<<
21st Test << >>>> <<<< < < <
M i t thi i f t ???Measures against this error in future ???
+
QA/QC Manual
When a (ICP-Forests) lab did not qualify and did not make efforts e a ( C o es s) ab d d o qua y a d d d o a e e o sto requalify, the ring test organizers [ICP Forests PCC] will send a letter to the National Focal Centre and inform them about the consequence that their data possibly cannot be used forconsequence that their data possibly cannot be used for evaluations on an European level.
Th lt f th i t t i t t d i th d t b f thThe results of the ring tests are integrated in the database of the PCC. This means that the bad ring test results will be marked as disqualified and this information can be used as a selection criterion for the monitoring data used in evaluations.
Re-qualification process
Please, ask your colleagues, if they have similar problems!Please, ask me for help with reference material or for hints.
Re-Qualification after the21st Needle/Leaf Ring Test21st Needle/Leaf Ring Test
Is mandatory for all „ICP-Forests laboratories“ if theyplan to:
Submit monitoring results from the sampling period2018/19 to the PCC database („growing saison“ 2018)2018)
Re-qualification process
Is a hard work for you (as headf th l b) i l b tof the lab) in your laboratory
and it needs time and it needsand it needs time and it needsmoney!
Re-qualification process
Final Deadline for finishing the requalification is 1st of September 2019
Yo r report has to contain o r labcode andYour report has to contain – your labcode and:
• Results of the re-analyzed ring test samples.P i t t f th i t t ( lib ti lib ti f t• Printouts from the instruments (calibration curves, calibration factors, measured results, date/time)
• Sample weights, dilution factors, moisture correction factors (if needed)Statement of the reason for failing the qualification• Statement of the reason for failing the qualification
• Measures against this error in future• Deadline for submitting your first draft report is 1st of August 2019!
This deadline is needed to discuss open questions in time before theThis deadline is needed to discuss open questions in time before the final deadline.
Special helping offer for these fourICP Forests labs (A60 A62 F07 F21)ICP-Forests labs (A60, A62, F07, F21) which failed in both testsRe-qualification (as usal)
Hint for avaliable reference materials (www.ffcc.at) for method validationFour extra unknown samples from older ring tests to check the measures in the lab before the next ring test!
A re-qualification is then only possible with all needed documents andcorrect results of these four extra samples!
At the moment two labs F07 and A62 haveAt the moment two labs F07 and A62 have requested these samples!
+
Reference material for methodvalidationvalidation
Maple leaves A• Maple leaves A• Litterfall-beech leaves (included As, Cr, Co, Hg, Ni)• Pine needles (Pinus nigra)
Spr ce needles B (incl ded As Cr Co Hg Ni)• Spruce needles B (included As, Cr, Co, Hg, Ni)
Details: http://bfw.ac.at/rz/bfwcms2.web?dok=5146
Accreditation status according EN 17025EN 17025
Types of control charts used in foliar laboratories (90 2% are using it !?)laboratories (90.2% are using it...!?)
Each ICP-Forests lab had to use it!
Normal analytical run in the lab
Calibration OK Samples OK
Control Chart (Average chart) –Internal Quality ControlInternal Quality Control
Results of these QC samples over time
Normal analytical run in the lab
These labs use control charts foranalyzing the four test samples !?analyzing the four test samples…!?
Labcode N S P Ca Mg K CA62 < <> <<<< <<< <<<
Labcode N S P Ca Mg K C
A85 >>> <<< <<<< <<<< <<<< <<<< >>>>
< too low result< too low result> too high result
What is a good result?
% Recovery close to 100% with a small variation between the foursample 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%
Accuracy of the mean & precision
% R 97 79 99 93% Vi 0 60 1 17%% Recovery = 97.79 – 99.93% Vi = 0.60-1.17%
% Recovery = 86.22 – 131.2% Vi = 2.97-7.89%
Frequency of ring test participation/year
22nd Needle/Leaf InterlaboratoryComparison Test 2019/20Comparison Test 2019/20
http://bfw.ac.at/ws/ring_nadel.login
Timetable - 22nd Test
Informing the participating labs via email (Febuary 2019)o g e pa c pa g abs a e a ( ebua y 0 9)• Registration of the participants via internet (Deadline July 1st,
2019) • Distribution of four test samples with an invoice (July 2019)• Distribution of four test samples with an invoice (July 2019) • Data submission by the labs (October-December 2019)• Deadline of data submission (Deadline January 1st, 2020)
Fi t lt (J 2020) d lifi ti t t d• First results (January 2020) and re-qualification process started• Final Report and online qualification report (February 2020)• Re-qualification process finished (Deadline September 1st, q p ( p
2020)
Samples for one of the next tests
6 of the last 8 foliage/litterfall samples are prepared from6 o e as 8 o age/ e a sa p es a e p epa ed oAustria
A lot of the samples have a low concentration of heavy metals A lot of the samples have a low concentration of heavy metals(Cd, Pb, As, Co, Hg)
I need someone who is willing to collect a sample!Leaf samples (beech?) are highly welcome!Heavy metal polluted samples are especially needed!
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