ISO 12937:2000 石油产品-卡尔费思特电位滴定法

标准编号：ISO 12937:2000

中文名称：石油产品-卡尔费思特电位滴定法

英文名称：Petroleum products — Determination of water — Coulometric Karl Fischer titration method

发布日期：2000-11

标准范围

本国际标准规定了直接测定石油产品沸腾中水分的方法低于390°C。其涵盖质量分数范围0,003%(m/m)至0,100%(m/m)。它不适用于产品含有酮或残余燃料油。本国际标准可适用于润滑基础油。然而，精度还没有为这些材料建立。第12条中给出的精度基于使用双电池、双电解质系统获得的数据。注1与缩合或氧化还原反应有关的若干物质和化合物类别干扰卡尔费休滴定法测定水分。在石油产品中，最常见的干扰是硫化氢和硫醇硫，然而，这些硫的质量分数低于0,003%（m/m）不会导致在0,003%（m/m）至0,100%（m/m）水范围内存在显著干扰。其他常见的有机硫化合物存在的如硫化物、二硫化物和噻吩不干扰。注2附件B中提供了一种替代程序，用于直接测定该范围内的水在石油产品中为0,003%（V/V）至0,100%（V/V）。这种替代体积测量可能受到的限制所用物质列于附录B。注3就本国际标准而言，术语“%(m/m)”和“%(V/V)”用于表示质量和材料的体积分数。

This International Standard specifies a method for the direct determination of water in petroleum products boilingbelow 390 °C. It covers the mass fraction range 0,003 % (m/m) to 0,100%(m/m). It is not applicable to productscontaining ketones or to residual fuel oils.This International Standard may be applicable to lubricating base oils. However, the precision has not beenestablished for these materials.The precision given in clause 12 is based upon data obtained using dual-cell, dual-electrolyte systems.NOTE 1 A number of substances and classes of compounds associated with condensation or oxidation-reduction reactionsinterfere in the determination of water by Karl Fischer titration. In petroleum products, the most common interferences arehydrogen sulfide and mercaptan sulfur, however, mass fractions of these below 0,003 % (m/m) as sulfur will not causesignificant interference over the range 0,003 % (m/m) to 0,100%(m/m) water. Other organic sulfur compounds commonlypresent such as sulfides, disulphides and thiophenes, do not interfere.NOTE 2 An alternative procedure is provided for information in annex B for the direct determination of water over the range0,003 % (V/V) to 0,100 % (V/V) in petroleum products. The limitations under which this alternative volume measurement may beused are listed in annex B.NOTE 3 For the purposes of this International Standard, the terms "% (m/m)" and "% (V/V)" are used to represent the massand volume fraction of a material respectively.

标准预览图