ISO 14388-2:2014 土壤质量 酸性硫酸盐土壤酸碱会计程序 第2部分：铬还原性硫法

标准编号：ISO 14388-2:2014

中文名称：土壤质量 酸性硫酸盐土壤酸碱会计程序 第2部分：铬还原性硫法

英文名称：Soil quality — Acid-base accounting procedure for acid sulfate soils — Part 2: Chromium reducible sulfur (CRS) methodology

发布日期：2014-08

标准范围

This part of ISO 14388 specifies a suite of methods used to determine the net acidity in acid sulfate soils.This part of ISO 14388 specifies a method for measuring chromium reducible sulfur (SCR) by iodimetrictitration of distilled hydrogen sulfide trapped as zinc sulfide, following acidic chromous chloridedigestion. This method determines inorganic sulfides (e.g. pyrite, marcasite, greigite, mackinawite) andelemental sulfur in acid sulfate soil without interferences from organic sulfur and oxidized forms ofsulfur such as sulfate.On a separate test portion of soil, the pH in a 1 mol/l KCl soil suspension (pHKCl) is determined. WhenpHKCl is < 6,5, titratable actual acidity (TAA) is then determined. Subsequently, potassium chlorideextractable sulfur (SKCl), calcium (CaKCl), and magnesium (MgKCl) can also be determined. Wherejarosite is identified in the soil (or where pHKCl is < 4,5), net acid-soluble sulfur (SNAS) is determined bythe difference between hydrochloric acid extractable sulfur (SHCl) and potassium chloride extractablesulfur. On samples where pHKCl is < 6,5, acid neutralizing capacity is determined by measuring eitherinorganic carbon (CIN) by combustion furnace, or ANCBT (ANC measured by back-titration of acidremaining following an acid digest).

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