HJ 804-2016Determination of Available Soil eight kinds of elements diethylenetriamine pentaacetic acid extraction - inductively coupled plasma emission spectrometry (English PDF)

3.1 Soil active elements

The elements that can be absorbed by the plant roots during the growing period of the plant, that is, under the conditions specified in this standard can be DTPA buffer solution is extracted from the soil.

5.1 Spectral interference

2 spectral interference, including spectral overlap interference and continuous background interference. Select the appropriate analysis line to avoid the overlap of spectral lines Interference, Table 2 for the measured elements in the proposed analysis of the wavelength of the main spectral interference. Use the instrument's own calibration software or interference Coefficient method to correct the spectral interference, when there is a single element of interference, according to formula (1) obtained interference coefficient.

Where. tK - interference coefficient;

'Q - content measured at the wavelength of the element, µg/L;

Q - Analysis of elemental content, µg/L;

TQ - the content of interfering elements, µg/L.

By preparing a series of known interfering element content solutions, the 'Q is determined at the position of the elemental wavelengths, (1) to find tK, and then artificial deduction or computer automatic deduction. Continuous background interference is usually deducted by the instrument Background method to eliminate. Note that the interferometric coefficients for different instruments are different.

Table 2 The main spectral interference of the element to be measured

Measured element wavelength/nm interference element to be measured wavelength/nm interference element Cu 324.754 327.396 Fe, Al, Ti, Mo Cd

214.438 Fe

239.924 Cr, W 226.502 Fe, Ni, Ti, Ce, K, Co

240.488 Mo, Co, Ni 228.806 As, Co, Sc

259.940 Mo, W

228.616

Ti, Ba, Cd, Ni, Cr,

Mo, Ce

261.762 Mg, Ca, Be, Mn 230.768 Fe, Ni Mn

257.610 Fe, Mg, Al, Ce 238.892 Al, Fe, V, Pb

293.306 Al, Fe

231.604 Fe, Co

202.548 Co, Mg 221.647 W

206.200 Ni, La, Bi Pb 220.353 283.306 Fe, Al, Ti, Co, Ce, Sn, Bi

213.856 Ni, Cu, Fe, Ti

5.2 Non-spectral interference

Non-spectral interference mainly includes chemical interference, ionization interference, physical interference and solvent interference. In the actual analysis process , All kinds of interference is difficult to separate. Whether it is compensated and corrected, and the concentration of interfering elements in the sample. In addition, Physical interference is generally caused by the viscosity of the sample and the surface tension changes, especially the sample contains a large number of soluble salts or Acid is too high, will interfere with the determination. An effective way to eliminate or reduce such interference is dilution or matrix matching (That is, the components of the standard solution used in addition to the target substance are consistent with the sample solution).

59.2 Drawing of standard curves

Ignite the plasma, according to the manufacturers to provide the operating parameters set, until the instrument preheat to the indicators after the stability of the open Start the measurement. Respectively, to remove a volume of multi-element standard solution (6.10.3) placed in a group of 100 ml volumetric flask, with a dip Extract (6.9) diluted to constant volume, mix. The lowest concentration point of the leaching solution (6.9) as the standard series was prepared at the same time 5 standard concentration of the standard series, the standard series of solution concentrations in Table 4. According to the optimized instrument reference conditions (9.1), the standard system Columns are sequentially analyzed from low concentration to high concentration into the atomizer. The mass concentration of the target element is the abscissa, corresponding to it the emission intensity is the ordinate and the standard curve is established. The concentration range of the standard curve can be determined according to the concentration of the element to be measured in the actual sample to adjust the situation.

Table 4 Standard Series Solution Concentration

Elemental C0 (mg/L) C1 (mg/L) C2 (mg/L) C3 (mg/L) C4 (mg/L) C5 (mg/L) Copper 0.00 0.25 0.50 1.00 2.00 4.00 Iron 0.00 5.00 10.0 20.0 40.0 80.0 Manganese 0.00 2.00 5.00 10.0 20.0 30.0 Zinc 0.00 0.20 0.50 1.00 2.00 4.00 Cadmium 0.00 0.01 0.02 0.04 0.08 0.12 Cobalt 0.00 0.10 0.20 0.30 0.40 0.50 Nickel 0.00 0.05 0.25 0.50 0.75 1.00 Lead 0.00 0.50 1.00 1.50 2.00 5.00

9.3 Determination

9.3.1 Determination of sample Before measuring the sample, rinse the system with nitric acid solution (6.7) until the instrument signal is minimized and the signal to be stabilized can begin to measure. The determination of the sample was carried out according to the same conditions and procedures as for the establishment of the standard curve (9.2). If the sample is to be tested the concentration of the element is outside the standard curve, and the sample must be re-measured after dilution. The diluent is extracted with the extract (6.9), diluted Multiple f

9.3.2 Determination of laboratory blank samples the laboratory blank samples were determined according to the same conditions and procedures as the test (9.3.1) of the sample.

10 results are calculated and expressed

10.1 Result calculation the content of the active elements in the soil sample (mg/kg) is calculated according to the formula (2) ( ) Dm FV Wx xx-= (2) where. - the content of the active element in the soil sample, mg/kg;

rho - by the standard curve to determine the determination of the effective concentration of the sample element concentration, mg/L;

6rho0 - mass concentration of active elements in laboratory blank samples, mg/L;

V - the volume of the extract added when the sample is prepared, ml;

F - the dilution factor of the sample;

M - the quality of the sample after sieving, g;

Wdm - dry matter content of soil samples,%.

10.2 results are shown the number of decimal places for the determination is consistent with the method detection limit, and a maximum of three significant digits are retained.

11 precision and accuracy 11.1 precision Six laboratory samples were used for three different levels of uniform soil standard samples and two different concentrations of actual soil samples Six parallel determinations were performed. The precision of the results is shown in Table A.1 in Appendix A.

11.2 Accuracy

Six laboratories carried out six parallel tests on soil samples of three different levels of soil, respectively.

With the concentration of the actual soil samples were 6 times the standard recovery rate determination. The accuracy of the results is given in Table A.2 in Appendix A.

12 quality assurance and quality control 12.1 each batch of samples to do at least two laboratory blank samples, the determination of the results should be lower than the lower limit of determination.

12.2 Each test shall establish a standard curve with a correlation coefficient >=0.999. Every 20 samples or per batch (less than 20 samples) Product/batch) sample, should be analyzed a standard curve of the middle concentration point, the measured results and the actual concentration of the relative deviation of <= 10% Otherwise, you should find the cause or reestablish the standard curve.

12.3 Each batch of samples shall be tested in parallel at least 10% of the proportions. If the number of samples is less than 10, at least one the relative deviation of the results of parallel samples should be less than 20%.

12.4 Each batch of samples shall be analyzed for at least one valid soil reference material. The results shall be determined in the range of uncertainty given Inside.

13 Waste treatment

Waste and waste generated in the experiment should be collected and stored in a sorted manner.

14 Precautions

14.1 The glassware used in the experiment shall be soaked in nitric acid solution (6.8) for 24 h, washed with tap water and experimental water, Placed in a clean environment to dry. Newly used or suspected contaminated container, applied with hot hydrochloric acid solution (6.6) soaked (temperature Higher than 80 °C, below the boiling temperature) 2 h or more, and hot nitric acid solution (6.8) soaking more than 2 h, followed by tap water and the experimental water rinse, placed in a clean environment to dry.

14.2 After the instrument is ignited, it should be preheated for more than 30 min to prevent wavelength drift.

14.3 When preparing standard solutions and preparing samples, use the same batch of formulated extracts.

7 Appendix A

(Informative)

Method of precision and accuracy summary data

Table A.1 gives the method for determining the precision of the eight active elements of this standard. Table A.2 shows the eight elements

Effective method of accuracy.

Table A.1 Summary of the precision of the method

Name Sample number

average value

(Mg/kg)

Laboratory relative

standard deviation(%) Inter-laboratory relative standard deviation(%) Repetitive limit r (Mg/kg) Reproducibility R (Mg/kg) Standard Sample 1 1.18 0.91 to 2.7 3.7 0.072 0.138 Standard sample 2 1.84 0.47 to 5.8 6.5 0.138 0.360 Standard sample 3 0.238 2.1 to 11 9.5 0.050 0.078 Actual sample 1 1.24 0.42 to 2.4 6.3 0.093 0.234 Actual sample 2 0.283 0.67 to 6.0 10 0.028 0.083 Standard sample 1 53.3 0.45 to 5.1 7.4 3.50 11.4 Standard sample 2 38.8 0.36 to 2.8 7.3 1.64 8.05 Standard sample 3 22.5 0.28 to 5.7 15 1.73 9.38 Actual sample 1 26.9 0.52 to 2.4 6.8 0.99 5.22 Actual sample 2 79.6 0.67 to 3.2 3.0 4.39 7.73 Standard sample 1 16.7 0.36 to 4.8 6.9 1.17 3.39 Standard sample 2 22.3 0.57 ~ 2.9 5.7 1.01 3.70 Standard sample 3 5.71 0.43 to 8.0 9.4 0.62 1.60 Actual sample 1 16.9 0.48 to 5.3 14 1.61 6.76 Actual sample 2 7.92 0.52 ~ 2.3 1.8 0.31 0.48 Standard sample 1 1.04 1.7 to 4.6 3.0 0.09 0.12 Standard sample 2 2.24 0.24 to 6.0 6.3 0.17 0.43 Standard sample 3 0.54 0.51 to 5.8 8.6 0.05 0.14 Actual sample 1 1.14 0.72 to 5.7 13 0.11 0.42 Actual sample 2 0.67 1.0 to 3.7 12 0.05 0.22 Standard sample 1 0.040 1.0 to 4.2 2.1 0.005 0.005 Standard sample 2 0.116 0.92 to 5.8 2.6 0.012 0.014 Standard sample 3 0.016 3.3 ~ 6.8 10 0.003 0.005 Actual sample 1 0.021 2.8 ~ 8.7 12 0.004 0.008 Actual sample 2 0.020 2.2 ~ 12 17 0.004 0.010 Standard sample 1 0.13 1.9 to 6.4 12 0.02 0.05 Standard sample 2 0.10 1.8 to 7.3 7.3 0.01 0.02 Standard sample 3 0.08 1.0 to 8.8 12.2 0.01 0.03 Actual sample 1 0.13 1.4 to 4.4 15 0.01 0.06 Actual sample 2 0.02 9.1 to 15 14 0.01 0.01 Standard sample 1 0.27 1.5 to 16 7.4 0.06 0.08 Standard sample 2 0.42 0.36 to 6.3 3.4 0.04 0.05 Standard sample 3 0.07 1.8 to 11 8.8 0.01 0.02 Actual sample 1 0.23 1.2 to 5.2 6.7 0.02 0.05 Actual sample 2 0.06 2.9 to 6.9 14 0.01 0.03 Standard sample 1 1.62 0.94 to 6.2 3.9 0.16 0.23 Standard sample 2 1.57 1.6 ~ 7.5 5.9 0.20 0.32 Standard sample 3 1.52 1.7 ~ 14.7 18 0.29 0.79 Actual sample 1 1.18 0.70 to 4.6 8.8 0.11 0.31 Actual sample 2 5.25 1.0 to 5.7 6.7 0.46 1.07

8 Table A.2 Summary of the accuracy of the method Name Sample number Recognized and incorrect (Mg/kg) Determine the mean (Mg/kg) Relative error (%) Relative error Final value (%) Spiked recovery rate range(%) Spiked recovery rate Final value (%) Standard sample 1 1.17 ± 0.07 1.18 -3.4 ~ 7.7 0.93 ± 7.5 //Standard Sample 2 1.85 ± 0.17 1.84 -9.2 ~ 9.2 -0.33 ± 13 //Standard sample 3 0.24 ± 0.04 0.238 -15 ~ 13 -0.70 ± 19 //Actual sample 1/1.24 // 86.7 to 113 99.7 ± 21.0 Actual sample 2/0.283 // 85.9 ~ 97.9 92.1 ± 8.8 Standard sample 1 55 ± 7 53.3 -12 ~ 6.6 -3.1 ± 14 //Standard sample 2 38 ± 5 38.8 -9.7 ~ 13 2.1 ± 15 //Standard sample 3 23 ± 5 22.5 -18 to 16 -2.0 ± 29 //Actual sample 1/26.9 // 90.8 ~ 114 102 ± 18.0 Actual sample 2/79.6 // 93.9 to 106 99.9 ± 10.2 Standard sample 1 17.3 ± 2.5 16.7 -11 to 4.1 -3.4 ± 13 //Standard sample 2 23 ± 3 22.3 -12 ~ 1.7 -2.9 ± 11 //Standard sample 3 5.7 ± 0.7 5.71 -12 ~ 13 0.12 ± 19 //Actual sample 1/16.9 // 90.0 to 139 106 ± 35.4 Actual sample 2/7.92 // 89.9 ~ 105 95.8 ± 10.2 Standard sample 1 1.08 ± 0.09 1.04 -6.5 ~ 0.93 -3.6 ± 5.6 Standard sample 2 2.4 ± 0.3 2.24 -14 ~ 3.3 -6.5 ± 12 Standard sample 3 0.53 ± 0.08 0.54 -14 ~ 8.3 1.7 ± 18 Actual sample 1/1.14 // 81.2 ~ 112 93.8 ± 21.4 Actual sample 2/0.67 // 83.2 ~ 102 94.0 ± 12.8 Standard sample 1 0.040 ± 0.003 0.040 -2.8 ~ 2.5 -0.74 ± 4.0 //Standard sample 2 0.12 ± 0.01 0.116 -6.7 ~ 0.0 -3.4 ± 5.0 //Standard sample 3 0.016 ± 0.004 0.016 -19 ~ 12 0.10 ± 21 //Actual sample 1/0.021 // 87.4 ~ 102 94.7 ± 11.3 Actual sample 2/0.020 // 92.0 ~ 114 99.5 ± 18.0 Standard sample 1 0.13 ± 0.04 0.13 -18 ~ 15 1.3 ± 24 //Standard sample 2 0.10 ± 0.03 0.10 -11 to 10 0.62 ± 15 //Standard sample 3 0.083 ± 0.018 0.08 -20 ~ 15 -1.9 ± 24 //Actual sample 1/0.13 // 83.6 ~ 104.8 95.9 ± 15.7 Actual sample 2/0.02 // 85.6 ~ 110.8 98.4 ± 18.6 Standard sample 1 0.27 ± 0.03 0.27 -11 to 7.8 0.98 ± 15 //Standard sample 2 0.43 ± 0.04 0.42 -7.7 ~ 0.27 -3.4 ± 6.7 //Standard sample 3 0.072 ± 0.012 0.07 -11 to 11 1.0 ± 18 //Actual sample 1/0.23 // 91.3 ~ 105 95.5 ± 10.0 Actual sample 2/0.06 // 89.7 to 104 95.0 ± 12.9 Standard sample 1 1.7 ± 0.2 1.62 -12 ~ -1.2 -4.9 ± 7.5 //Standard sample 2 1.6 ± 0.2 1.57 -12 ~ 2.5 -2.0 ± 12 //Standard sample 3 1.5 ± 0.4 1.52 -25 ~ 21 1.5 ± 36 //Actual sample 1/1.18 // 88.8 ~ 110 97.1 ± 15.0 Actual sample 2/5.25 // 90.7 to 104 95.7 ± 9.54