WAGENINGEN EVALUATING PROGRAMS FOR ANALYTICAL LABORATORIES Certificate of Analysis International Soil-Analytical Exchange REFERENCE MATERIAL ISE sample 946 $Dd
General Information Certificate of Analysis ISE 946 In this report an overview is given of analytical data for this sample collected in our proficiency testing program. The consensus values are calculated using a robust statistical model. With this NDA model mean and standard deviation are calculated using all reported data when at least 8 results are left after removal of reported 'lower than' (<) and 0 (= zero) values. No outliers are removed. This report is divided into three sections: Consensus Values, Indicative Values and Values for Information. The division is made on the reliability of the data. Consensus Values are based on at least 16 results while the coefficient of variation is smaller than 25 %. Indicative Values are based on at least 8 and less than 16 results or a coefficient of variation between 25 % and 50 %. Other values, based on less than 8 results or a coefficient of variation higher than 50 %, are given for information only. In the section with Consensus Values the following parameters are given: mean, standard deviation, coefficient of variation, number of results, median and MAD (Median of Absolute Deviation). The confidence limits (at 95 % probabilty) are calculated for these determinands. In the section with Indicative Values the following parameters are given: mean, standard deviation, coefficient of variation, number of results, median and MAD. In the section with Information Values the following parameters are given: median, MAD and number of results. For determinands which have at least 5 results reported as smaller than (<) the median of these smaller than results is calculated. In some cases this median of < values is much smaller than median and mean of the indicative values. This may be caused by a too opmistic (too low) value for the detection limit reported by a (small) majority of participating laboratories who report < -values. Sample information WEPAL reference materials are from natural sources only. There is no spiking, mixing or other alterations of the samples. ISE samples are dried at 40 o C and milled to pass a 0.5 mm sieve. This ISE sample 946 of Salt-marsh Soil from Ellewoutsdijk / Netherlands is prepared for the WEPAL proficiency programs. The sample is used in 1 period (or round). The results on which the values in this report are based were taken from the period given in the following table. Year Period Number 1995 1 1 1
Consensus Values ISE 946 Method: Real totals Zn mg/kg 272 27.0 9.9 17 269 18.8 258-286 Method: Acid extractable (So-called totals) Al g/kg 22.7 4.78 21.1 40 22.9 3.10 21.1-24.2 As mg/kg 26.9 3.10 11.5 61 26.9 2.10 26.1-27.7 B mg/kg 58.3 12.75 21.9 21 59.1 9.20 52.5-64.1 Ba mg/kg 66.1 14.60 22.1 29 64.0 10.10 60.6-71.7 Ca g/kg 56.6 4.17 7.4 65 56.5 2.80 55.6-57.6 Cd mg/kg 1.17 0.214 18.3 84 1.19 0.150 1.13-1.22 Co mg/kg 11.2 1.23 11.0 45 11.2 0.80 10.82-11.56 Cr mg/kg 84.2 11.53 13.7 82 84.8 7.85 81.7-86.8 Cu mg/kg 34.2 3.21 9.4 96 34.7 2.23 33.6-34.9 Fe g/kg 32.8 4.12 12.6 73 32.5 2.80 31.9-33.8 Hg µg/kg 958 165.1 17.2 54 975 110.0 913-1000 K mg/kg 6800 1692 24.9 52 6860 1110 6330-7270 Mg mg/kg 9190 781 8.5 67 9190 539 9000-9380 Mn mg/kg 732 68.8 9.4 73 735 48.1 716-748 N g/kg 4.25 0.257 6.0 55 4.21 0.180 4.18-4.32 Na mg/kg 10700 1210 11.2 41 10300 920 10350-11120 Ni mg/kg 27.0 3.67 13.6 82 27.0 2.45 26.2-27.8 P mg/kg 1610 191 11.8 55 1610 138 1560-1660 Pb mg/kg 93.3 9.68 10.4 84 93.2 6.70 91.2-95.4 S mg/kg 2430 120 4.9 17 2430 86 2370-2490 Sr mg/kg 164 14.2 8.7 17 161 10.0 156-171 V mg/kg 69.7 9.94 14.3 24 69.4 7.25 65.6-73.9 Zn mg/kg 247 26.0 10.6 95 249 18.0 241-252 Method: Extraction with boiling 2M HNO3 Cd mg/kg 1.21 0.126 10.4 32 1.20 0.085 1.17-1.26 Co mg/kg 9.41 0.833 8.8 25 9.54 0.560 9.07-9.75 Cr mg/kg 66.8 7.83 11.7 30 65.0 5.45 63.9-69.7 Cu mg/kg 31.1 1.62 5.2 33 30.8 1.10 30.6-31.7 Hg µg/kg 981 147.5 15.0 25 960 100.0 921-1040 Ni mg/kg 22.2 1.41 6.4 31 22.0 1.00 21.6-22.7 Pb mg/kg 96.9 6.14 6.3 33 97.2 4.30 94.7-99.0 2
Consensus Values ISE 946 Method: Extraction with boiling 2M HNO3 (cont.) Zn mg/kg 239 15.0 6.3 32 237 10.0 233-244 Method: Extraction with 0.1M NaNO3 Cu µg/kg 241 38.0 15.8 19 242 26.7 222-259 Method: Extraction with 0.01M CaCl2 1:10 K mg/kg 569 87.1 15.3 22 562 59.5 531-608 Mg mg/kg 1130 171 15.2 20 1120 125 1050-1210 N - NH4 (as N) mg/kg 7.00 1.363 19.5 16 7.39 0.925 6.28-7.72 N - NO3 (as N) mg/kg 19.0 3.34 17.5 16 20.2 2.38 17.3-20.8 Method: Soil characteristics EC-SC (ISO 11265) ms/m 831 93.5 11.2 25 811 72.0 793-870 Fraction < 2 µm % 31.9 7.23 22.7 19 32.2 4.80 28.4-35.4 Org.matter (L.O.I.) % 16.4 2.79 17.0 39 16.0 1.89 15.5-17.4 ph - CaCl2... 7.56 0.215 2.8 37 7.54 0.150 7.49-7.63 ph - H2O... 7.69 0.303 3.9 76 7.68 0.200 7.62-7.76 ph - KCl... 7.48 0.251 3.4 41 7.47 0.170 7.40-7.56 TIC=Tot.Inorg C(CaCO3) % 14.2 1.22 8.6 37 14.2 0.80 13.8-14.6 Method: Fluoride (Swiss standard procedure) F - Total mg/kg 514 61.9 12.0 16 490 44.5 481-546 3
Indicative Values ISE 946 Method: Real totals Al g/kg 57.3 2.16 3.8 11 57.2 1.41 As mg/kg 30.1 3.34 11.1 8 30.3 2.55 Ba mg/kg 264 29.2 11.1 8 272 20.0 Ca g/kg 59.8 2.42 4.0 11 59.8 1.75 Cr mg/kg 126 25.3 20.1 14 127 17.0 Cu mg/kg 37.6 4.22 11.2 15 37.3 2.60 Fe g/kg 38.2 1.31 3.4 14 38.0 0.90 Hg µg/kg 1020 176 17.2 9 1050 120 K mg/kg 18500 970 5.3 13 18400 700 Mg mg/kg 11400 1330 11.7 12 11100 930 Mn mg/kg 792 30.0 3.8 15 795 20.0 Na mg/kg 14100 1300 9.2 11 14000 820 Ni mg/kg 39.1 8.94 22.9 12 40.2 6.05 P mg/kg 1760 91 5.1 9 1760 60 Pb mg/kg 99.9 13.39 13.4 10 97.3 9.20 Si g/kg 223 7.8 3.5 8 225 5.6 Sr mg/kg 205 6.4 3.1 10 207 5.2 Method: Acid extractable (So-called totals) Results smaller than (<) Median of < N Be mg/kg 1.58 0.489 30.9 8 1.51 0.325 Li mg/kg 34.4 10.22 29.7 14 37.2 7.60 Sb mg/kg 1.04 0.292 28.2 9 1.10 0.200 5.00 7 Sn mg/kg 6.21 1.802 29.0 8 6.43 1.275 Method: Extraction with boiling 2M HNO3 Mo mg/kg 0.570 0.1647 28.9 12 0.585 0.1150 Method: Extraction with 0.1M NaNO3 Results smaller than (<) Median of < N Ni µg/kg 42.0 7.77 18.5 13 41.3 4.80 25.0 5 Zn µg/kg 70.5 21.30 30.2 14 70.3 15.20 50.0 5 4
Indicative Values ISE 946 Method: Extraction with 0.01M CaCl2 1:10 Na mg/kg 9600 876 9.1 10 9300 703 P mg/kg 3.59 0.560 15.6 15 3.54 0.370 Method: Extraction with 1M NH4NO3 1:2.5 (w/v) (DIN 19730) Cr µg/kg 25.2 5.84 23.1 8 25.5 3.90 Cu µg/kg 292 99.3 33.9 8 313 72.0 Method: Other determinations Results smaller than (<) Median of < N CN - Total mg/kg 1.28 0.284 22.2 9 1.30 0.200 1.00 5 Method: Water soluble 1:10 (w/v) (EN-12457-4) F mg/kg 20.9 3.24 15.5 12 20.7 2.05 Method: Phosphorus and related analysis P - Olsen (as P) mg/kg 107 33.9 31.8 28 105 23.2 5
Method: Real totals Be mg/kg 1.99 0.010 3 Br mg/kg 246 21.0 3 Cd mg/kg 1.24 0.125 6 Co mg/kg 13.6 0.40 7 F mg/kg 565 85.0 3 Ga mg/kg 18.0 1.00 3 I mg/kg 75.4 1.85 2 Li mg/kg 55.0 0.80 3 Mo mg/kg 2.14 1.865 2 Rb mg/kg 105 3.5 6 S mg/kg 3060 55 4 Sb mg/kg 1.95 0.550 5 Sn mg/kg 4.00 0.820 3 Y mg/kg 29.0 1.00 3 Zr mg/kg 190 27.5 6 Informative Values ISE 946 Method: Acid extractable (So-called totals) Results smaller than (<) Median of < N F mg/kg 36.4-1 Ga mg/kg 11.8 3.45 2 Mo mg/kg 1.47 0.775 12 2.00 11 Se mg/kg 0.875 0.0350 6 5.000 9 Si g/kg 0.830-1 Tl mg/kg 0.280 0.0100 3 Y mg/kg 13.6 1.60 3 Zr mg/kg 4.40 1.200 2 Method: Extraction with boiling 2M HNO3 Tl mg/kg 0.160 0.0200 7 Method: Extraction with 0.1M NaNO3 Results smaller than (<) Median of < N Cd µg/kg 3.06 0.060 7 5.00 13 Pb µg/kg 31.1 14.10 3 25.0 16 6
Method: Extraction with 0.01M CaCl2 1:10 B µg/kg 6390 488 2 Cu µg/kg 400 170.0 7 Fe mg/kg 0.700 0.4000 5 Mn mg/kg 0.460 0.1600 9 N total soluble mg/kg 63.0 5.50 5 Ni µg/kg 600-1 Zn µg/kg 520 420.0 5 Informative Values ISE 946 Method: Extraction with 1M NH4NO3 1:2.5 (w/v) (DIN 19730) Results smaller than (<) Median of < N As µg/kg 53.6 27.75 6 Cd µg/kg 10.03 3.700 8 Hg µg/kg 1.87 0.665 2 Ni µg/kg 47.3 6.10 7 Pb µg/kg 95.5 64.55 2 10.0 6 Tl µg/kg 12.6 0.45 2 Zn µg/kg 207 96.0 7 Method: Soil characteristics Fraction < 63 µm % 59.0 12.40 6 Fraction > 63 µm % 31.0 11.54 4 Method: Other determinations CN - Free mg/kg 0.0200-1 Method: Phosphorus and related analysis P - Bray (as P) mg/kg 28.3 16.30 20 7