Proficiency Test on soil improver maturity tests

Transkriptio

1 REPORTS OF FINNISH ENVIRONMENT INSTITUTE 7 0 Proficiency Test on soil improver maturity tests Liisa Maunuksela, Katarina Björklöf, Leena Kaarla, Mirja Kartio and Mirja Leivuori Finnish Environment Institute

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3 SUOMEN YMPÄRISTÖKESKUKSEN RAPORTTEJA 7 0 Proficiency test on soil improver maturity tests Liisa Maunuksela, Katarina Björklöf, Leena Kaarla, Mirja Kartio and Mirja Leivuori Finnish Food Safety Authority Evira, Helsinki, Finland Finnish Environment Institute, Centre, Helsinki, Finland SYKE Helsinki 0 Suomen ympäristökeskus

4 REPORTS OF FINNISH ENVIRONMENT INSTITUTE 7 0 Finnish Environment Institute SYKE The proficiency test provider: Finnish Food safety Authority Evira Mustialankatu, 0070 Helsinki, Finland tel. + (0) 0 000, fax + (0) 0 0 Proftest SYKE, Finnish Environment Institute (SYKE), Centre Hakuninmaantie 6, 000 Helsinki phone , fax + Publication is available only in the internet : ISBN (PDF) ISSN (Online)

5 CONTENT INTRODUCTION ORGANIZING THE PROFICIENCY TEST. Responsibilities. Participants. Samples, analytes and schedule. Homogeneity studies. Feedback from the pro ciency test 6.6 Processing of the data 6.6. Assigned values and their uncertainties 6.6. Standard deviation for pro ciency assessment and z score 7 RESULTS AND CONCLUSIONS 7. Results of the pro ciency test 7. Analytical methods.. Dry matter and organic matter content.. CO - evolution rate.. Oxygen uptake rate.. Plant response EVALUATION OF PERFORMANCE IMPORTANT ASPECTS 0 6 CONCLUSIONS 7 SUMMARY YHTEENVETO REFERENCES APPENDICES Appendix Terms in the result tables Appendix Results of participants presented graphically 6 Appendix Results of each participant Appendix Summary of the z scores 7 Appendix Evaluation of assigned values and their uncertainties DOCUMENTATION PAGE KUVAILULEHTI 0 PRESENTATIONBLAD

6 INTRODUCTION Evira carried out this pro ciency test for determining the effect of soil improvers on germination and root growth of cress, sample CO -production or oxygen uptake and dry weight and organic matter content. These tests are used for determining phytotoxicity and aerobic biological activity i.e. maturity-level of soil improvers. The pro ciency test was carried out in accordance with the international guidelines ISO/IEC 70 (ISO, 00), ISO (ISO, 00) and IUPAC Technical report (Thompson et al., 006). ORGANIZING THE PROFICIENCY TEST. Responsibilities. Participants This pro ciency test was planned and arranged by senior researcher Liisa Maunuksela and laboratory assistant Leena Kaarla at the Finnish Food Safety Authority Evira in collaboration with Proftest at Finnish Environment Institute (SYKE), where the expert on pro ciency testing was Katarina Björklöf. Proftest SYKE has been accredited by the Finnish Accreditation Service as a pro ciency testing provider (PT0, ISO/IEC 70, www. nas. ). The eld of the present test is not included in the accreditation scope. The homogeneity testing of the samples as well as the statistical treatment, including calculation of z-scores of the data set, was done by Proftest. Further, the layout of the report was done by Markku Ilmakunnas (SYKE). In this pro ciency test in total laboratories participated, from which six were from Finland and ve from other European countries (Table ). The organizer has code number three (analyses performed at the target date..0) and four (analyses performed days prior,..0) in the result tables. Only the organizer and participant number 0 were accredited. Table. Participants in the pro ciency test. Austria Germany Germany Ireland Finland France Austrian Agency for Health and Food safety, Vienna LUFA Nord-West, Oldenburg University of Applied Science Weihenstephan-Triesdorf, Freising Bord na Móna, Kildare Metropolilab Oy, Helsinki Viljavuuspalvelu Oy, Mikkeli Maa- ja elintarviketalouden tutkimuskeskus MTT, Jokioinen Teknologian tutkimuskeskus VTT, Espoo Novalab Oy, Karkkila Elintarviketurvallisuusvirasto Evira, Helsinki (two analysis on separate dates) SAS Laboratoire, Ardon. Samples, analytes and schedule Used sample codes on the result sheet were as follows: S Soil improver S Soil improver + peat Samples were collected..0 from a composting site in southern Finland established in April 0. Samples were pretreated and the laboratory compacted bulk density measured according to EN 00 by the organizer with the exception that sieving was done with a 0 mm sieve. The degree of wetting affects the magnitude of biological activity (Llewelyn, 00) and therefore samples were moistened to the approximate optimum moisture content according to the st test (FCQAO, ) before sending them to the participants. In addition, sample S was diluted with peat-based growing media (:). Measurements of ph and electrical conductivity from samples were measured according to standards EN 07, (0) and EN 0, (0).

7 For sample S ph was 6. and for sample S 7.. Conductivity was 0.6 ms/m for sample S and 7. ms/m for sample S. The sample amount sent to participants was 00 g. Fresh samples were delivered by cool storage to the participants -..0 and were therefore requested to be stored at - C before testing. Samples were requested to be homogenated before measurements and testing required to be done as soon as possible, preferably starting The results were requested to be reported no later than..0. The following measurements were reported. - DW: dry matter content (%) - Org: organic matter content (%) - CO : CO -production/bottle (%) - CO : CO -evolution rate (mg CO -C/g VS/d), calculated result correcting CO - evolution rates with dry weight and organic matter content - Oc: oxygen consumption (mmol O /kg OM) - OUR: oxygen uptake rate (mmol O x kg - x OM x hour - ) - AGR: plant response, average germination rate (%) - RI: plant response, root length index (%) - GR: germination rate (%) - RLP: root length, per plant (mm). Homogeneity studies Samples N and N for homogeneity test were collected on 7..0 from the same location and similar piles as the pro ciency test samples using the same sampling scheme on both sampling occasions. Homogeneity testing was performed for humidity, organic matter, CO production and root length using two different pretreatments (sieving mm and 0 mm) and ve parallel samples with two or three analytical parallels per sample (Table ). Homogeneity was tested using guidelines from IUPAC technical report (Thompson et al. 006). The objective of the homogeneity study was to establish the heterogeneity of the samples used in this pro ciency test. This information has to be taken into account when setting the criteria for evaluations of performance. Samples could be considered homogenous for humidity and organic matter allowing.-. % deviation, but deviations of -60 % was required for the homogeneity criteria for CO production and root length (RLP) to be ful lled. This re ects natural heterogeneity of biological processes in these organic samples.

8 6 Table. Results from the homogeneity testing of samples N and N. Sample Matrice Parameter Mean value Sp % Sp S an S an /Sp Is S an /sp<0.? S sam S sam c N mm Humidity, % 7,7,0,07 0,0 0, Yes 0,60 0, 0, Yes Organic matter, % 7,6,,0 0,0 0, Yes 0,7 0,0 0, Yes CO production ( h),mg CO -C/g VS /d,06 0,7 0, 0,7 Yes 0,0 0,0 0,070 Yes Rooth length (RLP), mm 0, 6 0,7 0,06 0,6 Yes 0,0 0,00 0,06 Yes 0 mm Humidity, % 6,,0,0 0, 0,6 Yes 0,07 0,7 0, Yes Organic matter, %,06,, 0, 0,6 Yes 0, 0,0 0, Yes CO production ( h),mg CO -C/g VS /d 0, 0, 0,6 0, Yes 0,0 0,00 0,060 Yes Rooth length (RLP), mm 0, 60 0, 0,0 0,7 Yes 0,7 0,0 0,0 Yes N mm Humidity, % 7,,0,0 0,6 0,6 Yes 0,0 0,07 0,6 Yes Organic matter, % 6,,,0 0, 0,6 Yes 0, 0,00 0, Yes CO production ( h),mg CO -C/g VS /d,0 0,6 0,0 0, Yes 0, 0,0 0,7 Yes Rooth length (RLP), mm,6 0, 0, 0, Yes 0, 0,0 0,077 Yes 0 mm Humidity, % 6,,0,6 0, 0,7 Yes 0,76 0,7, Yes Organic matter, % 6,,,0 0,6 0,6 Yes 0,70 0,7 0,0 Yes CO production ( h),mg CO -C/g VS /d,6 0, 0, 0,7 Yes 0, 0,06 0,0 Yes Rooth length (RLP), mm, 6 0, 0,0 0, Yes 0, 0,0 0,0 Yes Is S sam < c? s p = Assigned standard deviation for homogeneity test, (total standard deviation divided by ) s p % = Assigned standard deviation for homogeneity as percent, (total standard deviation divided by ) s an = analytical deviation, mean standard deviation of results in a sub sample s sam = sampling deviation, standard deviation of results between sub samples c = F sall + F sa where: sall = (0. st) F =. when the number of sub samples is 6, F =.6 when the number of sub samples is 6 F =. when the number of sub samples is 0, F =.0 when the number of sub samples is 0. Feedback about the pro ciency test The participants did not comment on the arrangements or the evaluation procedures. Many of the reported results had to be corrected after sending of the results. The following corrections were made: correction of units (laboratory 7), missing data (laboratories and ) and results reported reversed results for the two samples (laboratory 0). The organizers strongly recommend that results should be carefully reported to ensure good customer service..6 Processing of the data Results were treated according to international ISO-guidelines (ISO, 00). Before the statistical treatment, the data was tested according to the Kolmogorov-Smirnov normality test and the outliers were rejected according to the Hampel test for calculation of the mean value (H in the results sheets)..6. Assigned values and their uncertainties The robust mean was used as the assigned value for measurements of the sample (Table, Appendix ). The robust mean is not a metrological traceable assigned value. Because it was not possible to have a metrological traceable assigned value, the consensus mean was the best available value to use for the assigned values. Before the robust calculation of the reference value, some outliers were rejected in case that the results deviated from the robust mean more than 0 % or in case that the result was reported erroneously (e.g. wrong unit). If the result was reported < DL (detection limit), it has not been included in calculation of the reference value (H in the results sheets). The uncertainties of the assigned values were. % and. % for organic matter contents in the samples S and S respectively and. % for dry weight measurements (Appendix ). For other parameters, the uncertainties of the assigned values were. % - 7 %. The reliability criterion u/s p 0. was not fully met because the u/s p was between (Appendix ) which is indicated by the high uncertainty of the assigned value.

9 7.6. Standard deviation for pro ciency assessment and z score The performance evaluation of each participant was carried out by using z scores (Appendix ). The target values for the total standard deviations for each analyte (Table, *target SD %), used in the calculation of the z score of the target value, were estimated directly from the total SD r % of the data set. The reliability criterion, s rob <. * s p was met in all cases except for RLP in sample S (Appendix ). Therefore the evaluation of performance is only indicative for RLP measurements in sample S. z scores were not calculated for CO (S), CO production per bottle (samples S and S), and root length index (RI; S) due to high standard deviation of the data set for these analytes. For oxygen consumption (Oc) and oxygen uptake rate (OUR) z scores were not calculated due to small data set (n=). For control materials z scores are not appropriate to calculate because the results are not comparable, due to differences in control material. RESULTS AND CONCLUSIONS. Results of the pro ciency test The summary of the results is presented in Table. Explanations to terms used in the result tables are presented in Appendix. The results of participants are presented graphically in Appendix and the reported results of each participant in Appendix. A summary of z-scores are presented in Appendix and the evaluation of assigned values and their uncertainties are presented in Appendix. Table. Summary of the results in the pro ciency test. Ass. Val.- assigned value; Mean- mean value; Mean rob-robust mean; Md- median value; SD rob - the robust standard deviation; SD rob % - robust standard deviation as percent; Num of Labs - number of participants; *Targ. SD% - total standard deviation for pro ciency assessment at % con dence level, (*s p ); Accepted z-val% - satisfactory z scores: the results (%), where < z ±.

10 The results for some parameters were requested to be reported as triplicate (Table ). The repeatability of the results (sw%) were often below 0 % but slightly higher for RLP and were highest for CO production per bottle (sample S = % and sample S = %) and for oxygen consumption (sample S = %). These levels are acceptable considering the sample heterogeneity. In a similar study the mean repeatability for compost samples producing. -0. mg CO /g/vs/day was.0 mg CO /g/vs/ (Llewelyn, 00). For a compost sample producing. mg CO /g/vs/day the repeatability was.7 mg CO /g/vs/day (Llewelyn, 00). For chemical analyses the reproducibility between laboratories (sb%) are typically about - times higher than the repeatability which was the case for dry weight and organic matter content results. Sb% values were similar or even less for some measurements (CO -production, GR, Oc, RLP for S) but for CO -evolution rate, oxygen uptake rate (OUR) and RLP for S and control, the sb% values were - times higher than the repeatability values. Table. Summary of repeatability on the basis of triplicate determinations (ANOVA statistics).. Analytical methods Six laboratories analyzed the samples on the requested date and laboratory 7 a couple of days later due to sample shipment delay. number analyzed the samples after ca. two weeks and laboratory number 0 measured organic and dry matter contents immediately after sample arrival and the biological analysis after ca. two weeks.... Dry matter and organic matter content All the laboratories performed the analysis using the gravimetric methods based on EN standards 00 and 0. Temperature ranged from 60 o C to 0 o C for dry matter analysis and from 0 o C to 0 o C for organic matter analysis.... CO - evolution rate Description of analysis performed by the laboratories is combined in Table.

11 Table. Summary of CO -production analysis in the laboratories. Lab No Method Equipment Flask volume (ml) and septum type Incubation time and temperature Closed bottle VTT Oxybaby V 600-6, silicon h/7 o C *, Closed bottle VTT Checkmate 00 00, rubber h/7 o C Closed bottle VTT CheckPointII 00 h/7 o C 6 Gas chromatograph HP , rubber 6 h/7 o C Closed bottle VTT Dräger tubes 6, silicon h/7 o C 0 Closed bottle, NaOH trap Closed bottle VTT Servoflex MiniFoodpack 00 *Itävaara et al. 006, 00.. Oxygen uptake rate.. Plant response TOC meter 00 7 h/ o C 00, rubber h/7 o C Only two labs performed the OUR test, both according to EN standard Number of replicates was two or three and the incubation temperature used was 0 o C or 0 o C. No clear conclusion can be drawn from these results due to low participation. Description of analysis is combined in Table 6. All laboratories used the standard method EN 606- and vegetable cress seeds with germination capacity of > 0%. Total number of seeds ranged from 0 to 0/sample. All laboratories incubated samples for 7 h. Table 6. Summary of plant response analysis in the laboratories. Lab No Control material Sphagnum peat (ph.-6) + water soluble fertilizer + trace elements, Filter paper Whatman Filter paper Whatman 6 Limed peat 0 7 Peat H-H (+ PG mix + ground limestone) 0 Limed and fertilized peat 0 Sphagnum peat Sphagnum peat Incubation temperature C) EVALUTION OF PERFORMANCE The evaluation of the participants was based on z scores, which were calculated using the estimated target values for the total deviation. The z scores shall be interpreted as follows: Criteria Performance z Satisfactory < z < Questionable z Unsatisfactory

12 0 In total, % of the results were satisfactory when target deviations between -0 % of the assigned values were accepted (Table ). The results of eight participants were all satisfactory (z-values between - and ). Please note that the evaluations of the following analytes are indicative only due to very high target standard deviations (0-0 %, Table ): CO (S) RI (S) RLP (S, S) After reporting the preliminary results in January 0, results from four laboratories were corrected (e.g. change of unit; cm, mm) and data was supplemented for organic matter contents and dry matters. These changes are re ected in the following evaluations: org, DW, AGR (S), R (S, S) and RLP (S, S). IMPORTANT ASPECTS FROM THE PROFICIENCY TEST CO -production. Analysis of sample CO -production was performed mainly using the same principle method but with different equipment and incubation times (Table ). The results were clearly different for the CO measurement and the CO -evolution rates between different laboratories. This was true especially for sample S. In addition to sample heterogeneity, factors such as equipment used ( ask volume, septum type and machinery for measurement) probably had an effect on the result. For this type of soil improver samples, CO evolution of approximately.0 mg CO -C/g VS/d would be expected (Itävaara et al., 00). Here, the mean CO evolution of the pro ciency tests was.7 mg CO -C/g VS/d for S and. mg CO -C/g VS/d for S. Results from laboratory (and 6) were considerably lower. 6 used gas chromatography for CO production which may explain the difference compared to other laboratories. The reason for exceptionally low result for laboratory number remains unclear. All laboratories except one reported slightly higher CO -production and CO -evolution rates for sample S than S. This can be due to the addition of peat into sample S, which may have activated microbial respiration rates. It should be taken into account that the quality of peat used for dilution of soil improvers during testing can affect the results. Moisture content and temperature also have a major effect on biological activity of materials and therefore method optimization is critical. We recommend that harmonization of this test protocol should be continued. Oxygen uptake rate. Only two laboratories analyzed oxygen uptake rate and there was some difference in the oxygen consumption measurements, probably resulting from sample heterogeneity. In addition, incoherency was found between the OUR results of sample S, perhaps due to calculation error in the laboratory. Correlation between the measurement of oxygen uptake and CO evolution has been shown earlier (Itävaara et al., 006). Plant response. In the plant response/petri dish method, germination rate (AGR) results between the laboratories were comparable except for one laboratory for sample S. Root length measurements (RLP) however and therefore also root index (RI) calculated from these measurements varied from mm to 6 mm (RI:, to 0) for S and 0 mm to 6 mm (RI: to 77) for S. Controls, incubation temperature and the amount of seeds used varied between the laboratories (Table 6) but this doesn t explain the big differences between root length measurement data, especially for sample S (laboratories 7 and ). Differences in root measurement may have been caused by uncertainty in the measurement of seedling root (Figure ), especially with short roots or mainly only shoot growth it may have not always been clear what to measure. Also sample maturation may have occurred prior to testing, since laboratory performed the analysis two weeks after the recommended date. It seems the instructions described in the standard procedure are not suf ciently detailed and therefore allow for subjective opinions. Further harmonization is needed e.g. by training courses.

13 Figure. Measurement of root length of germinated cress seed. Except for laboratories 7 and, sample S gave better cress root growth results than sample S. This is in accordance with previous studies where peat has been shown to stimulate cress root growth (Maunuksela et al., 0). Laboratories and, using inert lter paper as control, had RI variation between and (S) and and 6 (S). Root length (RLP) of control seedlings on lter paper varied from 6 mm to 6 mm between the laboratories, so probably also seed quality, incubation temperature and lter paper moisture had an effect on the results. Maturity assessment. Since these tests are used for soil improver maturity and stability assessment, a conclusion of sample maturity according to laboratory results is depicted in Table 7. Stability and root growth test results showed no clear relationships. Criteria for soil improver maturity in Finnish legislation are: CO -evolution, < mg CO -C/gVS/d and root length index, > 0%. According to Wood et al. (00), very stable (biowaste and green waste) compost is classi ed as < mg CO -C/gVS/d CO -evolution and < mmol O /kg VS/h O evolution rates. Stabilities of <6 mg CO /g VS/day are desirable for growing media purposes or for any applications where selfheating would be a problem. According to these three criteria, sample S was considered mature and stable by only two laboratories, sample S by none. The current maturity criteria for soil improvers in the Finnish legislation (root index, RI>0 %) is too strict due to changes in the standard procedure (incubation time) which causes bigger differences in relation to the control. The criteria will be updated. Table 7. Maturity assessment of analyzed samples *according to Wood et al., 00 **according to Finnish Act on Fertilizer Products

14 6 CONCLUSIONS This pro ciency test was in our knowledge the rst pro ciency test performed after the interlaboratory test performed in 00 in relation to validation of the standard (EN 606-, 0). Sample dispatch time, humidity of the samples and storage temperature are known to affect the results. Therefore the samples used in our test were pretreated by sieving and wetting to the same moisture content and consequently the samples analysed were more homogenous than in earlier intercalibrations. The deviations of the results in this test are thus smaller and evaluation of competence was possible for some of the analytes. It seems many laboratories have good experience of these methods even though they have been standardized only recently. In some of the participating laboratories all methods were not routinely in use, and we appreciate their participation in these tests despite of this. Pro ciency test provide important feedback on laboratory analytics and will help all participants to further improve their performance. The analyses used in this pro ciency test are used for determining soil improver maturity and stability. Stability and plant response test results showed no clear relationships, which complicate the interpretation of results when several test are performed on the same material. Similar conclusions have been made in other studies (Wood et al., 00). The diversity of biological processes in soil improver samples is a challenge for this type of pro ciency tests as it is dif cult to separate deviations caused by methodological reasons and natural diversity of the samples. This has been considered during performance evaluation by using wide target standard deviations. In future rounds of pro ciency tests also pretreatment practices, like wetting of the samples, would be interesting to take into account. This will increase standard deviations further. We thank all participants for taking part in this pro ciency test and are happy to receive feedback and requests concerning the next round of pro ciency test.

15 7 SUMMARY Evira and Proftest SYKE carried out this pro ciency test in November-December 0 for sample phytotoxicity and aerobic biological activity by determining the effect of soil improver samples on germination and root growth of cress, sample CO -production or oxygen uptake and sample dry weight and organic matter content. In total laboratories took part in this test. Sample material was soil improver (S) and soil improver and peat based growing medium (S). Standard methods were used to determinate the properties from the samples, except for CO evolution rate analysis for which no standard exist. The robust means of the reported results by the participants were used as the assigned values for measurements. The evaluation of performance was based on the z scores which were calculated using the standard deviation for pro ciency assessment. z scores were not calculated for CO (S), CO production per bottle, and root length index (RI; S), oxygen consumption (Oc) and oxygen uptake rate (OUR). In total, % of the results were satisfactory when the deviations of -0 % from the as-signed values were accepted. It seems further guidance in some of the methods is needed. Results for aerobic biological activity and plant response (phytotoxicity) showed no clear relationships, which complicate the interpretation of results when several test are performed on the same material. According to the results many laboratories have good practices and manage these analyses well. Other laboratories still need more experience. In future rounds of pro ciency tests also pretreatment practices will be taken into account. YHTEENVETO Evira toteutti yhdessä Proftest SYKEn kanssa maanparannusaineiden fytotoksisuutta ja aerobista biologista aktiivisuuta (stabiilisuutta) koskevan vertailukokeen marras-joulukuussa 0. Vertailukokeen kahdesta näytteestä tutkittiin krassin itävyys ja juuren kasvu, hiilidioksidintuotto tai hapen kulutus sekä näytteiden kuivapaino ja orgaanisen aineen määrä. Pätevyyskokeeseen osallistui yhteensä laboratoriota. Näytemateriaalina käytettiin maanparannusainetta (S) ja maanparannusaineen ja turpeen sekoitusta (S). Laboratoriot käyttivät standardimenetelmiä näytteiden ominaisuuksien tutkimiseen paitsi hiilidioksidituoton määrityksessä, missä standardit puuttuvat kyseiselle matriisille. Mittaussuureen vertailuarvona käytettiin osallistujien ilmoittamien tulosten robustia keskiarvoa. Laboratorioiden pätevyyden arviointi tehtiin z-arvon avulla. Tavoitehajonta määritettiin pätevyyskokeen hajonnan perusteella. z-arvoja ei määritetty hiilidioksidille (S), hiilidioksidituotto per pullo tai juurenpituus-indeksille (RI; S), hapen kulutukselle (Oc) tai hapen sitoutumisnopeudelle (OUR). Kaikkiaan % tuloksista oli hyväksyttäviä, kun tavoitehajonta oli of -0 % tavoitearvosta. Kahdeksalla laboratoriolla oli kaikki tulokset hyväksyttäviä. Aerobista biologista aktiivisuutta määrittävien testien ja kasvivastetta määrittävien testien tulokset eivät antaneet selvää korrelaatiota, mikä vaikeutti tulosten tulkintaa. Tulosten perusteella kierrokseen osallistuvat laboratoriot hallitsevat kyseiset analyysit pääasiassa hyvin vaikka jotkut laboratoriot tarvitsevat enemmän kokemusta tietyissä analyyseissä. Tulevissa pätevyyskokeissa tullaan huomioimaan myös laboratorioiden suorittama näytteen esikäsittelyprosessi.

16 REFERENCES EN 07, (0). Soil improvers and growing media Determination of ph EN 0, (0). Soil improvers and growing media Determination of electrical conductivity EN 0, (0). Soil improvers and growing media. Determination of organic matter content and ash EN 00, (007). Soil improvers and growing media Sample preparation for chemical and physical tests, determination of dry matter content, moisture content and laboratory compacted bulk density EN 606-, (0). Soil improvers and growing media. Determination of plant response. Part : Petri dish test using cress. EN 607-, (0). Soil improvers and growing media. Determination of the aerobic biological activity. Part : Oxygen uptake rate (OUR) FCQAO. (). Methods Book for the Analysis of Compost Kompost information Nr 0. BGK ed. International standardization Organization. ISO (00). ISO/IEC 70 Conformity assessment General requirements for pro ciency testing. International standardization Organization. ISO (00). ISO, Statistical methods for use in pro ciency testing by interlaboratory comparisons Itävaara M., Kapanen, A., Venelampi O. and Vuorinen A. (006). Kompostin kypsyystestit: Menetelmäohjeet. VTT tiedotteita Itävaara, M., Vikman, M., Maunuksela, L. and Vuorinen, A. Maturity tests for composts -veri cation of a test scheme for assessing maturity (00). Compost Sci. & Util. Vol., No., 7- Llewelyn, R. H. (00). Development of standard laboratory based test to measure compost stability. The waste & Resources Action programme, project code ORG000, Research Report: Organics. ISBN: Maunuksela, L., Herranen, M. and Torniainen, M. (0). Quality Assessment of Biogas Plant End Products by Plant Bioassays. International Journal of Environmental Science and Development. Vol. (): 0-0. Thompson, M., Ellison, S.L. R., Wood, R. (006). The International Harmonized Protocol for the Pro ciency Testing of Analytical Chemistry laboratories (IUPAC Technical report). Pure Appl. Chem. 7: -6 ( Wood, M., Wallace, P., Becvar, A. and Waller, P. BSI PAS 00 Update Review of stability testing (00).

17 TERMS IN THE RESULT TABLES APPENDIX Results of each participants Sample the code of the sample z-graphics z score - the graphical presentation z value calculated as follows: z = (x i - X)/s p, where x i = the result of the individual laboratory X = the reference value (the assigned value) s p = the target value of the standard deviation for proficiency assessment Outl test OK yes - the result passed the outlier test H = Hampel test (a test for the mean value) In addition, in robust statistics some results deviating from the original robust mean have been rejected Assigned value the reference value * Targ SD % the target value of total standard deviation for proficiency assessment (s p ) at the % confidence level, equal s p Lab s result the result reported by the participant (the mean value of the replicates) Md. Median Mean Mean SD Standard deviation SD% Standard deviation, % Passed The results passed the outlier test Outl. failed The results not passed the outlier test Missing i.e. < DL Num of labs the total number of the participants Summary on the z scores S satisfactory ( - z ) Q questionable ( < z < ), positive error, the result deviates more than s p from the assigned value q questionable ( - > z< -), negative error, the result deviates more than s p from the assigned value U unsatisfactory (z ), positive error, the result deviates more than s p from the assigned value u unsatisfactory (z -), negative error, the result deviates more than s p from the assigned value Robust analysis X * = median of x i (i =,, p) s * =. median of x i x* (i =,, p) s. ( x i /( p x * i = x * - if x i < x * - x * i = x * + if x i > x * + x * i = x i otherwise x ) ) The robust estimates x * and s * can be derived by an iterative calculation, i.e. by updating the values of x * and s * several times, until the process convergences. Ref: Statistical methods for use in proficiency testing by inter laboratory comparisons, Annex C [].

18 LIITE. LABORATORIOIDEN TULOKSET GRAAFISESTI APPENDIX.RESULTS OF PARTICIPANTS PRESENTED GRAPHICALLY 6 LIITE APPENDIX / AGR S % AGR S % CO S,,, 0, 0-0, SYKE - Interlaboratory comparison test /0

19 LIITE APPENDIX / 7 CO S,,6,, 0, 0,6 0, CO- S 0, 0, 0,7 0,6 % 0, 0, 0, 0, 0, CO- S, 0, 0, % 0,7 0,6 0, 0, 0, SYKE - Interlaboratory comparison test /0

20 LIITE APPENDIX / DW S 0 7 % DW S % GR S % SYKE - Interlaboratory comparison test /0

21 LIITE APPENDIX / GR S % GR control S/S 00 6 % Oc S SYKE - Interlaboratory comparison test /0

22 0 LIITE APPENDIX / Oc S org S % org S % SYKE - Interlaboratory comparison test /0

23 LIITE APPENDIX / 6 OUR S 0, 0,, 7, 7 6, 6, OUR S,,,,6,,, Rl S % SYKE - Interlaboratory comparison test /0

24 LIITE APPENDIX / 7 Rl S % RLP S mm RLP S mm SYKE - Interlaboratory comparison test /0

25 LIITE APPENDIX / RLP control S/S 6 60 mm SYKE - Interlaboratory comparison test /0

26 LIITE APPENDIX / LIITE. LABORATORIOKOHTAISET TULOKSET APPENDIX.Results of each participant Analyte Unit Sample z-graphics Z- value Outl Assigned test OK value * Targ SD% Lab's result Md. Mean SD SD% Passed Outl. failed Missing Num of labs AGR % S 0,6 yes, 00 7,0,6 6, 0 -,0 yes, 0 6,7,6,,6 0 0 DW % S -0,7 yes 6, 6,6 6, 0,67, 0-0,06 yes, 7,7,, 0, 0 0 GR % S 0,76 yes, , 7,6 7, 7 0-0,0 H, GR control % S/S yes ,0,6, 0 0 org % S -0, yes 60, 6,7 60,6 60,6,, 0-0,6 yes 67, 66,6 67, 67,,06,6 0 0 Rl % S yes,6 7,, 6,7 0 0,66 yes 67, 0,6 6, 66,7,, 0 0 RLP mm S 0, yes, 0,, 7, 0, 0 0 mm S 0,70 yes,6 0,67,,7 7,, 0 0 RLP control mm S/S yes 0,67 6, 7,6 0,,0 0 CO S -,06 yes,7 0 0,67,07,067 0,6 6, 0 0 S yes, 0,,0, 0,7 0, 0 0 CO- % S yes 0, 0, 0, 0,,0 0 0 H 0, 0,7 0,77 0,0,6 0 DW % S,67 H 6, 6 7,6 6, 0,67, 0 0, yes, 7 0,,, 0, 0 0 org % S -0, C 60, 6,0 60,6 60,6,, 0 0,0 yes 67, 67, 67, 67,,06,6 0 0 AGR % S 0,0 yes, 7 7,0,6 6, 0 0,7 yes, 00 6,7,6,,6 0 0 CO S 0,7 yes,7 0,,07,067 0,6 6, 0 0 S yes,,67,0, 0,7 0, 0 0 CO- % S yes 0,6667 0, 0, 0,,0 0 0 yes 0, 0,7 0,77 0,0,6 0 DW % S -0, yes 6, 6, 6, 0,67, 0-0,7 yes, 7,7,, 0, 0 0 GR % S 0, yes,6 6,67 00, 7,6 7, 7 0 0, yes, GR control % S/S yes 6, ,0,6, 0 0 org % S -0,6 yes 60, 6 60, 60,6 60,6,, 0-0, yes 67, 66,7 67, 67,,06,6 0 0 Rl % S yes 7,, 6, ,70 yes 67, 0 6, 66,7,, 0 0 RLP mm S -0,6 yes, 0,67,, 7, 0, 0 0 mm S 0,00 yes,6 0,67,,7 7,, 0 0 RLP control mm S/S yes 6,67 6, 7,6 0,,0 0 AGR % S 0,0 yes, 7 7,0,6 6, 0-0,0 yes, 6,7,6,,6 0 0 CO S 0, yes,7 0,77,07,067 0,6 6, 0 0 S yes,,6,0, 0,7 0, 0 0 CO- % S yes 0,7 0, 0, 0,,0 0 0 yes 0,7667 0,7 0,77 0,0,6 0 DW % S 0, H 6, 6 7,0 6, 0,67, 0 0, yes, 7,,, 0, 0 0 GR % S 0, yes,6 6,67 00, 7,6 7, 7 0-0, H,6, GR control % S/S yes 6, ,0,6, 0 0 org % S 0,0 H 60, 6 6, 60,6 60,6,, 0-0,00 yes 67, 67, 67, 67,,06,6 0 0 Rl % S yes 7,, 6, , yes 67, 0 6, 66,7,, 0 0 RLP mm S -,0 yes, 0,667,, 7, 0, 0 0 mm S -, yes,6 0 0,,,7 7,, 0 0 RLP control mm S/S yes 6 6, 7,6 0,,0 0 Outlier test failed: C - Cohcran, G - Grubbs(-outlier algorithm), G - Grubbs(-outliers algorithm), H - Hampel, M - manual SYKE - Interlaboratory comparison test /0

27 LIITE / APPENDIX Analyte Unit Sample z-graphics Z- value Outl Assigned test OK value * Targ SD% Lab's result Md. Mean SD SD% Passed Outl. failed Missing Num of labs AGR % S -0, yes, 7,0,6 6, 0-0,0 yes, 6,7,6,,6 0 0 CO S 0, yes,7 0,,07,067 0,6 6, 0 0 S yes,,767,0, 0,7 0, 0 0 CO- % S yes 0,667 0, 0, 0,,0 0 0 yes 0,7 0,7 0,77 0,0,6 0 DW % S 0,0 yes 6, 6 6, 6, 0,67, 0 0, yes, 7 0,,, 0, 0 0 GR % S -0,7 yes,6, 00, 7,6 7, 7 0-0,0 H, GR control % S/S yes 00 7,0,6, 0 0 org % S 0, yes 60, 6 6, 60,6 60,6,, 0 0,0 yes 67, 67,7 67, 67,,06,6 0 0 Rl % S yes 7,, 6, ,0 yes 67, 0 6 6, 66,7,, 0 0 RLP mm S 0, yes, 0,, 7, 0, 0 0 mm S 0,6 yes,6 0 6,67,,7 7,, 0 0 RLP control mm S/S yes 6, 6, 7,6 0,,0 0 6 AGR % S -0,76 yes, 0 7,0,6 6, 0 0,7 yes, 00 6,7,6,,6 0 0 CO S -0,7 yes,7 0 0,70,07,067 0,6 6, 0 0 S yes, 0,767,0, 0,7 0, 0 0 DW % S -0, yes 6, 6, 6, 0,67, 0-0,70 yes, 7,06,, 0, 0 0 GR % S -0,6 yes,6 0 00, 7,6 7, 7 0 0, yes, GR control % S/S yes 6, ,0,6, 0 0 org % S -0,06 yes 60, 6 60, 60,6 60,6,, 0 0, yes 67, 67, 67, 67,,06,6 0 0 Rl % S yes 7,, 6,7 0 0,76 yes 67, 0 7 6, 66,7,, 0 0 RLP mm S 0,70 yes, 0,,, 7, 0, 0 0 mm S 0,7 yes,6 0 6,,,7 7,, 0 0 RLP control mm S/S yes 7,67 6, 7,6 0,,0 0 7 AGR % S -,00 H, 6,7 7,0,6 6, 0 -,0 yes, 0 6,7,6,,6 0 0 DW % S 0,0 yes 6, 6 6,7 6, 0,67, 0 0,0 yes, 7 0,,, 0, 0 0 GR % S -,0 H,6 6,667 00, 7,6 7, 7 0-0,0 H, GR control % S/S yes, 00 7,0,6, 0 0 org % S 0,67 yes 60, 6 6,7 60,6 60,6,, 0-0, yes 67, 67, 67, 67,,06,6 0 0 Rl % S yes,6 7,, 6, , yes 67, 0 60,7 6, 66,7,, 0 0 RLP mm S -,0 yes, 0 0,6667,, 7, 0, 0 0 mm S -, yes,6 0,7,,7 7,, 0 0 RLP control mm S/S yes 0, 6, 7,6 0,,0 0 CO S -0,6 yes,7 0 0,67,07,067 0,6 6, 0 0 S yes, 0,,0, 0,7 0, 0 0 DW % S,67 H 6, 6 7, 6, 0,67, 0, yes, 7,,, 0, 0 0 org % S 0, yes 60, 6 6, 60,6 60,6,, 0, yes 67, 6, 67, 67,,06,6 0 0 Outlier test failed: C - Cohcran, G - Grubbs(-outlier algorithm), G - Grubbs(-outliers algorithm), H - Hampel, M - manual SYKE - Interlaboratory comparison test /0

28 6 LIITE APPENDIX / Analyte Unit Sample z-graphics Z- value Outl Assigned test OK value * Targ SD% Lab's result Md. Mean SD SD% Passed Outl. failed Missing Num of labs AGR % S 0,6 yes, 00 7,0,6 6, 0 0,7 yes, 00 6,7,6,,6 0 0 DW % S -, yes 6, 6, 6, 0,67, 0 -,0 yes, 7 7,6,, 0, 0 0 Oc S yes, 7,, 6,6, 0 0 S yes, 0,7,,7 0, 0 0 org % S,7 yes 60, 6 6, 60,6 60,6,, 0,7 H 67, 7, 67, 67,,06,6 0 0 OUR S yes 0,7, 7,,0 0,7 0 0 S yes,6,6,6,0, 0 Rl % S yes,7 7,, 6, , yes 67, 0 60, 6, 66,7,, 0 0 RLP mm S 0, yes, 0,7,, 7, 0, 0 0 mm S -0,6 yes,6 0,7,,7 7,, 0 0 RLP control mm S/S yes 6,77 6, 7,6 0,,0 0 0 AGR % S -,70 yes,, 7,0,6 6, 0 0,7 yes, 00 6,7,6,,6 0 0 CO S -0,70 yes,7 0 0,0,07,067 0,6 6, 0 0 S yes, 0,7,0, 0,7 0, 0 0 DW % S -0,0 yes 6, 6 6,0 6, 0,67, 0 0,7 yes, 7 0,,, 0, 0 0 GR % S -, yes,6, 00, 7,6 7, 7 0 0, yes, GR control % S/S yes ,0,6, 0 0 org % S -0,6 yes 60, 6, 60,6 60,6,, 0-0,7 yes 67, 66, 67, 67,,06,6 0 0 Rl % S yes, 7,, 6, ,7 yes 67, 0 6, 6, 66,7,, 0 0 RLP mm S -, yes, 0,,, 7, 0, 0 0 mm S 0, yes,6 0,6,,7 7,, 0 0 RLP control mm S/S yes,7 6, 7,6 0,,0 0 AGR % S 0,6 yes, 00 7,0,6 6, 0 0, yes, 6,7 6,7,6,,6 0 0 DW % S -0, yes 6, 6,6 6, 0,67, 0-0, yes, 7,,, 0, 0 0 GR % S 0,76 yes, , 7,6 7, 7 0-0, H,6, GR control % S/S yes ,0,6, 0 0 Oc S yes 7, 7,, 6,6, 0 0 S yes 6 0,7,,7 0, 0 0 org % S -0,6 yes 60, 6 60,0 60,6 60,6,, 0-0,7 yes 67, 66, 67, 67,,06,6 0 0 OUR S yes,, 7,,0 0,7 0 0 S H,67,6,6,0, 0 Rl % S yes 0,0 7,, 6, , yes 67, 0 76,7 6, 66,7,, 0 0 RLP mm S 6,077 yes, 0 6,,, 7, 0, 0 0 mm S,0 yes,6 0 6,,,7 7,, 0 0 RLP control mm S/S C 60, 6, 7,6 0,,0 0 CO S,6 yes,7 0,,07,067 0,6 6, 0 0 S yes,,00,0, 0,7 0, 0 0 CO- % S yes 0, 0, 0, 0,,0 0 0 yes 0,6667 0,7 0,77 0,0,6 0 DW % S -0,0 yes 6, 6 6,0 6, 0,67, 0-0,06 yes, 7,7,, 0, 0 0 org % S 0,0 H 60, 6 60,7 60,6 60,6,, 0 0, H 67, 6, 67, 67,,06,6 0 0 Outlier test failed: C - Cohcran, G - Grubbs(-outlier algorithm), G - Grubbs(-outliers algorithm), H - Hampel, M - manual SYKE - Interlaboratory comparison test /0

29 7 LIITE APPENDIX / LIITE. YHTEENVETO z - ARVOISTA APPENDIX. SUMMARY OF z SCORES Analyte Sample\Lab AGR S S. S S S S u. S S S. S S. S S S S S. S S S. 00 CO S. q S S S S. S. S. S S CO-prod/bottle S S DW S S S S S S S S S S S S S 00 S S S S S S S S S q S S S GR S S. S S S S u.. S S. S S. S S S S S.. S S. 00 GR control S/S Oc S S org S S S S S S S S S S S S S 00 S S S S S S S S S U S S S OUR S S Rl S S S. S q S S S. S S S. RLP S S. S S S S q. S q U. 67 S S. S S S S S. S S Q. RLP control S/S % Accredited yes yes yes % %* - percentage of satisfactory results Totally satisfactory, % In all: In accredited: In non-accredited: 0 SYKE - Interlaboratory comparison test /0

30 APPENDIX EVALUATION OF ASSIGNED VALUE AND THEIR UNCERTAINTIES All assigned values and their uncertainties were calculated using robust statistics. The reliability of the assigned value was tested according to the criterion: u/s p 0., where u is the standard uncertainty of the assigned value (the expanded uncertainty of the assigned value (U) divided by ) and s p the standard deviation for proficiency assessment (total standard deviation divided by ). The assigned values used in this comparison test cannot be considered reliable according to this criterion. The reliability of the target value for the total deviation and the reliability of the corresponding z score were estimated by comparing the deviation for proficiency assessment (s p ) with the robust standard deviation of the reported results (s rob ). The criterion s rob <.* s p was fulfilled for all evaluations except RLP (S). Measurement Sample Assigned value Sd rob U % Sp u/s p Is Sd rob <. Sp? AGR S,,6, 7,6 0, Yes S,,0,,7 0,6 Yes CO S,7 0,, 0,6 0, Yes DW S 6, 0,, 0,7 0,6 Yes S, 0,,,0 0, Yes GR S,6 6, 6,,06 0, Yes S,6,,0, 0, Yes org. S 60,,,, 0, Yes S 67,,,, 0, Yes R S 67, 0,7,6,7 0, Yes RLP S, 6,6 7, 6, 0,7 Yes S,6,, 6, 0,6 No

31 Documentation page Publisher Finnish Environment Institute (SYKE) Date May 0 Author(s) Liisa Maunuksela, Katarina Björklöf, Leena Kaarla, Mirja Kartio and Mirja Leivuori Title of publication Parts of publication/ other project publications Abstract Proficiency Test on soil improver maturity tests The publication is available only in the internet Evira and Proftest SYKE carried out this proficiency test in November-December 0 for sample phytotoxicity and aerobic biological activity by determining the effect of soil improver samples on germination and root growth of cress, sample CO -production or oxygen uptake and sample dry weight and organic matter content. In total laboratories took part in this test. Sample material was soil improver (S) and soil improver and peat based growing medium (S). Standard methods were used to determinate the properties from the samples, except for CO evolution rate analysis for which no standard exist. The robust means of the reported results by the participants were used as the assigned values for measurements. The evaluation of performance was based on the z scores which were calculated using the standard deviation for proficiency assessment. z scores were not calculated for CO (S), CO production per bottle, and root length index (RI; S), oxygen consumption (Oc) and oxygen uptake rate (OUR). In total, % of the results were satisfactory when the deviations of -0 % from the as-signed values were accepted. It seems further guidance in some of the methods is needed. Keywords Publication series and number Theme of publication According to the results many laboratories have good practices and manage these analyses well. Other laboratories still need more experience. In future rounds of proficiency tests also pretreatment practices will be taken into account. proficiency test, soil inprovers, phytotoxicity, carbon dioxide production, compost, maturity assessment, oxygen uptake rate Suomen ympäristökeskuksen raportteja 7 / 0 Project name and number, if any Financier/ commissioner Project organization ISSN ISBN (online) (PDF) No. of pages Language English Restrictions Public Price For sale at/ distributor Financier of publication Printing place and year Helsinki 0 Other information Finnish Environment Institute, Customer service neuvonta.syke@ymparisto.fi Phone Fax Finnish Environment Institute, P.O.Box 0, FI-00 Helsinki, Finland

32 0 Kuvailulehti Julkaisija Suomen ympäristökeskus (SYKE) Julkaisuaika Toukokuu 0 Tekijä(t) Liisa Maunuksela, Katarina Björklöf, Leena Kaarla, Mirja Kartio ja Mirja Leivuori Julkaisun nimi Julkaisun osat/ muut saman projektin tuottamat julkaisut Tiivistelmä Proficiency Test on soil improver maturity tests Julkaisu on saatavana vain internetistä. Evira toteutti yhdessä Proftest SYKEn kanssa maanparannusaineiden fytotoksisuutta ja aerobista biologista aktiivisuuta (stabiilisuutta) koskevan vertailukokeen marras-joulukuussa 0. Vertailukokeen kahdesta näytteestä tutkittiin krassin itävyys ja juuren kasvu, hiilidioksidintuotto tai hapen kulutus sekä näytteiden kuivapaino ja orgaanisen aineen määrä. Pätevyyskokeeseen osallistui yhteensä laboratoriota. Näytemateriaalina käytettiin maanparannusainetta (S) ja maanparannusaineen ja turpeen sekoitusta (S). Laboratoriot käyttivät standardimenetelmiä näytteiden ominaisuuksien tutkimiseen paitsi hiilidioksidituoton määrityksessä, missä standardit puuttuvat kyseiselle matriisille. Mittaussuureen vertailuarvona käytettiin osallistujien ilmoittamien tulosten robustia keskiarvoa. Laboratorioiden pätevyyden arviointi tehtiin z-arvon avulla. Tavoitehajonta määritettiin pätevyyskokeen hajonnan perusteella. z-arvoja ei määritetty hiilidioksidille (S), hiilidioksidituotto per pullo tai juurenpituus-indeksille (RI; S), hapen kulutukselle (Oc) tai hapen sitoutumisnopeudelle (OUR). Kaikkiaan % tuloksista oli hyväksyttäviä, kun tavoitehajonta oli of -0 % tavoitearvosta. Kahdeksalla laboratoriolla oli kaikki tulokset hyväksyttäviä. Asiasanat Julkaisusarjan nimi ja numero Julkaisun teema Tulosten perusteella kierrokseen osallistuvat laboratoriot hallitsevat kyseiset analyysit pääasiassa hyvin vaikka jotkut laboratoriot tarvitsevat enemmän kokemusta tietyissä analyyseissä. Tulevissa pätevyyskokeissa tullaan huomioimaan myös laboratorioiden suorittama näytteen esikäsittelyprosessi. pätevyyskoe, maanparannusaine, fytotoksisuus, hiilidioksidin tuotto, komposti, kypsyysaste, hapen kulutus Suomen ympäristökeskuksen raportteja 7 / 0 Projektihankkeen nimi ja projektinumero Rahoittaja/ toimeksiantaja Projektiryhmään kuuluvat organisaatiot ISSN ISBN (verkkoj.) (PDF) Sivuja Kieli englanti Luottamuksellisuus Julkinen Hinta Julkaisun myynti/ jakaja Julkaisun kustantaja Painopaikka ja -aika Helsinki 0 Muut tiedot Suomen ympäristökeskus, asiakaspalvelu Sähköpostiosoite: neuvonta.syke@ymparisto.fi puh faksi Suomen ympäristökeskus, PL 0, 00 Helsinki

33 Presentationsblad Utgivare Finlands Miljöcentral (SYKE) Datum Maj 0 Författare Liisa Maunuksela, Katarina Björklöf, Leena Kaarla, Mirja Kartio och Mirja Leivuori Publikationens titel Publikationens delar/ andra publikationer inom samma projekt Sammandrag Proficiency Test on soil improver maturity tests Publikationen finns tillgänglig på internet Livsmedelssäkerhetsverket Evira genomförde tillsammans med Finlands miljö central (SYKE) i november 0 en kompetensprövning om jordförbättringsmedels fytotoxiska verkan och aerobiska biologiska aktivititet (stabilitet). Från komptensprövningens två prov undersöktes krassens groning och rotens längd under tillväxt i proverna, provernas koldioxidförbrukning och syreförbrukning samt torrvikten och mängden organiskt material i proverna. Totalt elva laboratorier deltog i komptensprövningen. Provmaterialet bestod av jordförbättringsmedel (S) och en blandning av jordförbättringsmedel och torv (S). Laboratorierna använde standardiserade undersökningsmetoder utom för produktion av koldioxid, för vilken det inte finns någon standard för denna matris. Nyckelord Publikationsserie och nummer Publikationens tema Som det åsatta värdet användes det robusta medelvärdet av deltagarnas resultat. Laboratoriernas kompetens bedömdes med z-värden. Det beräknade värdet för standardavvikelsen för det åsatta värdet beräknades från deltagarnas robusta standardavvikelse. z-värden beräknades inte för koldioxid (S), koldioxid per flaska eller index-värdet för rotens längd (RI, S), syreförbrukningen (Oc) eller bindningshastigheten för syre (OUR). Total var % av resultaten goda när -0% avvikelse från det åsatta värdet godkändes. Åtta laboratorier hade alla resultaten goda. På basen av resultaten har många av laboratorierna goda rutiner fast en del av laboratorierna behöver mera erfarenhet. I kommande kompetensprövningar kommer också provernas förbehandlingar beaktas. kompetensprövning, fytotoxicitet, koldioxid production, kompost, mognadsgraden av kompost, syreförbrukning Suomen ympäristökeskuksen raportteja 7 / 0 Projektets namn och nummer Finansiär/ uppdragsgivare Organisationer i projektgruppen ISSN ISBN (online) (PDF) Sidantal Språk Engelska Offentlighet Offentlig Pris Beställningar/ distribution Förläggare Tryckeri/ tryckningsort och år Finlands miljöcentral, informationstjänsten neuvonta.syke@ymparisto.fi Tfn Fax Finlands Miljöcentral, PB 0, 00 Helsingfors Helsingfors 0 Övriga uppgifter

34 SYKE PROFICIENCY TEST 7/0 ISBN (PDF) ISSN (online) SYKE FINNISH ENVIRONMENT INSTITUTE