BS EN 15692 pdf free download

BS EN 15692-2021 pdf free download.Ethanol as a blending component for gasoline – Determination of water content- Karl Fischer potentiometric titration method.
This document specifies a method for the direct determination of water in ethanol to be used as a
blending component for petrol, as well as in automotive ethanol (E8S) fuel.
This method is applicable in the range 0,05 % (rn/rn) to 0,54 % (rn/rn).
NOTE For the purposes of this document, the term “% (rn/mr is used to represent the mass fraction.
WARNING — — Use of this document might involve hazardous materials, operations and equipment. This document does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this document to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN ISO 3170, Petroleum liquids – Manual sampling (ISO 3170)
EN ISO 3696. Water for analytical laboratory use – Specification and test methods (ISO 3696)
3 Terms and definitions
For the purposes of this document, the following term and definition apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• I EC Electropedia: available at https://w ww.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1 water content
content of water determined by potentiometric Karl Fischer procedure as given in this document
4 Principle
A weighed test portion is injected into the titration vessel of a potentiometric Karl Fischer apparatus. The water present is titrated to a potentiometric end point using Karl Fischer reagent. Iodine (12), with presence of anhydride sulfur (SO2), of methanol (CH3OH) and of an appropriate nitrogen base (RN), is introduced for the Karl Fischer reaction. Based on the stoichiometry of the reaction, one mole of iodine reacts with one mole of water.
5 Reagents and materials
Use only chemicals and reagents of recognized analytical grade.
5.1 Karl Fischer reagent, pyridine-free Karl Fischer (KF) reagent, containing iodine, sulfur dioxide and an odourless amine and with a nominal water equivalent content of either 2 mg or 5 mg water per ml equivalent.
The Karl Fisher reagent shall be standardized daily before use (see &1).
5.2 Titration solvent methanol, anhydrous methanol containing less than 0,05 % (rn/rn) of water.
5.3 Water, complying with grade 3 of EN ISO 3696.
6 Apparatus
6.1 Karl Fischer titrator, using a potentiometric end-point.
NOTE Karl Fischer titrators are commercially available and some of them automatically stop the titration at the end-point. Instructions for operation of these devices are provided by the manufacturer and are not described here. The method described in this document Is using a titrator with a 5 ml burette.
6.2 Electrode platinum/platinum
6.3 Syringes
NOTE Needles with bores between 0,5 mm and 0,8 mm have been found suitable, such as syringe of single use with Luer connection, 5 ml or 10 ml capacity.
6.3.1 Syringe, of approximately 10 uI capacity, fitted with a needle of sufficient length to enable the tip to reach under the surface of the liquid in the titration vessel when inserted through the inlet-port septum.
6.3.2 Syringe, of approximately 10 ml capacity, fitted with a needle of sufficient length to enable the tip to reach under the surface of the liquid in the titration vessel when inserted through the inlet-port septum.
6.4 Analytical balance, capable of weighing to the nearest 0,1 mg.
6.5 Automatic burette, of 5 ml or 10 ml capacity, protected from humidity by the use of a molecular sieve (fJ.) at the top.
Although it is recommended that an automatic burette connected to a reservoir containing the KF reagent (5d) is used, a burette, of approximately 5 ml capacity, fitted with a guard tube filled with molecular sieve (6) to prevent the ingress of moisture, may also be used.
6.6 Molecular sieve, granulometry proximally 1,6 mm to 2.5 mm, pore size close to 1 nm.
If required to be dried it shall be placed in an oven at proximally 140 °C for about 8 hours, then cooled In
a desiccator to room temperature.
7 Sampling and sample handling
7.1 Samples shall be taken as described in EN ISO 3170.
7.2 Take care to minimize the uptake of atmospheric moisture during sampling and sample handling.
73 Samples shall be shaken before used.BS EN 15692 pdf download.