石油产品 水分的测定 库仑卡尔·费休滴定法

[中文适用范围]： 本标准规定了沸点低于390℃的石油产品中水的直接测定方法。 它涵盖的质量分数范围为 0.003 % (m/m) 至 0.100 % (m/m)。 它不适用于含有酮的产品或残余燃料油。 本国际标准可适用于润滑油基础油。 然而，这些材料的精度尚未确定。 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：许多与缩合或氧化还原反应相关的物质和化合物类别会干扰卡尔费休滴定法测定水的量。 在石油产品中，最常见的干扰是硫化氢和硫醇硫，然而，这些物质的质量分数低于 0,003 % (m/m)，因为硫在 0,003 % (m/m) 至 0,100 %（米/米）水。 其他常见的有机硫化合物，如硫化物、二硫化物和噻吩，不会产生干扰。 注 2：附件 B 中提供了一种替代程序，用于直接测定石油产品中 0.003%（V/V）至 0.100%（V/V）范围内的水分。 可以使用这种替代体积测量的限制在附录 B 中列出。 注 3：就本国际标准而言，术语“%（m/m）”和“%（V/V）”用于表示分别为材料的质量分数和体积分数。 [外文原描述]： This International Standard specifies a method for the direct determination of water in petroleum products boiling below 390 °C. It covers the mass fraction range 0,003 % ( m/m ) to 0,100%( m/m ). It is not applicable to products containing ketones or to residual fuel oils. This International Standard may be applicable to lubricating base oils. However, the precision has not been established 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 reactions interfere in the determination of water by Karl Fischer titration. In petroleum products, the most common interferences are hydrogen sulfide and mercaptan sulfur, however, mass fractions of these below 0,003 % ( m/m ) as sulfur will not cause significant interference over the range 0,003 % ( m/m ) to 0,100%( m/m ) water. Other organic sulfur compounds commonly present 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 range 0,003 % ( V/V ) to 0,100 % ( V/V ) in petroleum products. The limitations under which this alternative volume measurement may be used 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 mass and volume fraction of a material respectively.