LY/T 1231-1999 PDF EnglishUS$70.00 · In stock · Download in 9 seconds
LY/T 1231-1999: Determination of ammonium nitrogen in forest soil Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Obsolete
LY/T 1231-1999: Determination of ammonium nitrogen in forest soil---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/LYT1231-1999GB FORESTRY INDUSTRY STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA (Adjusted from GB 7851-1987) Determination of ammonium nitrogen in forest soil APPROVED ON. JULY 15, 1999 Implemented on: NOVEMBER 1, 1999 Issued by. State Forestry Authority Table of ContentsForeword ... 3 1 Scope ... 4 2 Normative references ... 4 3 Methods and key points ... 4 4 Reagent ... 4 5 Main instruments ... 4 6 Determination procedures ... 4 7 Results calculation ... 5 8 Allowable deviation ... 5ForewordThis standard is a revision of GB/T 7851-1987 “Determination of ammonium nitrogen in forest soil”. In this revision, the unit that does not conform to the national legal metrological unit AND the terms that do not conform to the soil science’s terms as published by the National Scientific Terminology Review Committee are modified; In the compilation, it is compiled in accordance with the requirements of GB/T 1.1-1993. As for the determination of ammonium nitrogen in the soil, there are mainly direct distillation method, post-extraction determination method, and ammonia electrode method. This standard adopts the magnesium oxide extraction - diffusion method, which is easy to operate and easy to control conditions, AND applicable to the determination of large amount of soil samples. AND it is featured by fast analysis speed and good result reproducibility. From the date of implementation of this standard, the original GB/T 7851-1987 is abandoned. This standard shall be under the jurisdiction of the Forestry Research Institute of China Academy of Forestry. The drafting organizations of this standard. Forestry Soil Research Institute, Forestry Research Institute, Chinese Academy of Forestry. The main drafters of this standard. Zhang Wanru, Yang Guangying, Tu Xingnan, Zhang Ping. Determination of ammonium nitrogen in forest soil1 ScopeThis standard specifies the method for the determination of ammonium nitrogen in forest soil by the magnesium oxide extraction - diffusion method. This standard is applicable to the determination of ammonium nitrogen in forest soil.2 Normative referencesThe provisions in following documents become the provisions of this Standard through reference in this Standard. The versions indicated at the time of publication of this standard are valid. All standards are subjected to revision, AND parties who reach an agreement based on this Standard are encouraged to study if the latest versions of these documents are applicable. LY/T 1229-1999 Determination of hydrolyzable nitrogen in forest soil3 Methods and key pointsPLACE the soil samples directly on the outer chamber of the diffusion dish; USE the weak alkaline magnesium oxide aqueous suspension to exchange the ammonium nitrogen attached to the soil colloid; MAINTAIN the temperature at 40 °C for 5 ~ 6 hours to release the ammonium, which is absorbed by the boric acid in the inner chamber. USE the standard diluted acid to titrate it; DETERMINE ammonium nitrogen content.4 Reagent4.1 170 g/L magnesium oxide solution. WEIGH 17.0 g of magnesium oxide which had been burnt at 500 ~ 600 °C; ADD 100 mL of water; SHAKE it uniformly before use. 4.2 The other reagents are the same as those in clause 4.3 of LY/T 1229-1999.5 Main instrumentsDiffusion dish (outer chamber 10 cm), dropper (5 mL).6 Determination procedures6.1 WEIGH 1.00 ~ 2.00 g of dried soil sample which had passed the 2 mm sieve; SPREAD in the outer chamber of the diffusion dish; PIPETTE 3 mL of 20 g/L ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. 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