GB 9838-1988 N soil and plant standard samples GB9838-1988 standard download decompression password: www.bzxz.net
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National Standard of the People's Republic of China 15N soil and plant standard samples Standard soil and plant sarnplesfor 15N isotope rate analysisSubject content and scope of application UDC 631.423 GB 9838--88 This standard sample includes soil and plant materials. This standard is applicable to 15N soil and plant standard samples for calibrating mass spectrometers and spectrometers for 15N analysis, verifying 15N analysis methods and 15N analysis data of various laboratories. 2Source and preparation of 15N standard samples 2.1 Enriched 15N soil samples Taken from Beijing brown soil on the campus of Beijing Agricultural University, liquid ammonia with high 15N abundance was applied in the micro-area in 1983, and rice was planted. The soil was left for another year, mixed and ground, sieved, mixed again, and bottled, 30g per bottle. 2.2 15N enriched plant samples Water-torn stems and leaves, and applied high-abundance 15N ammonium sulfate in the field micro-area at a later stage. Harvest after the rice matures, remove the roots and ears, wash and dry, chop, grind into powder, sieve, mix well, and pack in plastic bags, 2g per bag. 2.3 15N natural abundance plant samples Stems and leaves of upland rice plants taken from the field, washed, dried, chopped, ground into powder, sieved, mixed well, and packed in plastic bags, 2g per bag. After the plant samples and soil samples were sealed, they were irradiated with 4.9 Mrad of diamond 60-rays and stored in the dark at room temperature (10-35℃). 3 Fineness and uniformity of standard samples 3.1 Fineness: All plant samples passed through a 60-mesh (aperture 0.25mm), and soil samples passed through a 100-mesh (aperture 0.149mm) sieve. 3.2 Uniformity: 20 bags were randomly sampled and tested 200 times. The abundance of 15N-enriched plant samples was 0.691±4.9×10-3, and the CV% was 0.71; the abundance of 15N-enriched soil samples was 0.441±2.9×10-3, and the CV% was 0.66. The results showed that the samples were mixed evenly. 4 Standard values of standard samples The collaborative group conducted repeated and long-term measurements on this standard sample, and the results are as follows: Sample name 15N natural abundance plant sample Enriched I5N plant sample Enriched 15N soil sample Note: The reference value of N% is for reference. 5 Storage and use of standard samples 5.1 Protect from light and store in a dry place at a temperature not exceeding 30℃. 5.2 Stir with a horn spoon before use to mix again. Approved by the Ministry of Agriculture of the People's Republic of China on June 30, 198827.1 15N atomic% 0. 366±0. 001 0.688±0.003 0.441±0.003 Implemented on March 1, 1989bzxz.net GB9838-88 5.3 General analysis amount: weigh at least 1g for soil and at least 0.2g for plant samples. Additional remarks: This standard was drafted by the Isotope Group of Beijing Agricultural University, the Mass Spectrometry Group of Nanjing Institute of Soil Science, Chinese Academy of Sciences, and the Institute of Physics and Chemistry of Hebei Academy of Agricultural and Forestry Sciences. The main drafters of this standard are Peng Genyuan, Cao Yacheng, Chen Liang and Peng Yunsheng. 275 Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.