ISO INTERNATIONAL UB'Ti3 Hannover. STANDARD 86 13757 RN First edition 1996-07-15 Liquefied petroleum gases - Deterrnination of oily residues High-temperature method Gaz de pétrole liquefiés -Determination des résidus huileux - Méthode ahautetemperature ISO Reference number ISO 13757:1996(E) INTERNATIONAL STANDARDISO IS013757:1996(E) Liquefied petroleum gases --- Determination of oily residues ---- High-temperature method - The use of this International Standard may involve hazardous materials, operations WARNING and equipment. This International Standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Scope 3 Definition This International Standard specifies a method for the For the purposes of this International Standard, the determination of the residual matter in liquefied pet- following definition applies. roleum gases (LPG) that remains after evaporation at 105 °C. This material, termed "oily residues", rep- 3.1 liquefied petroleum gas: Hydrocarbon gas that resents thoseproductsthat aredeposited in can be stored and/or handled in the liquid phase under vaporizers that are subject to a heat input greater than moderate conditions of pressure and at ambient tem- that of ambient evaporation. perature. It consists essentially of C and C4 alkanes or alkenes, or a mixture of these, contains generally less than 5 % by liquid volume of material of higher carbon number, and has a gauge vapour pressure not 2 Normative references exceeding approximately 1 600 kPa at 40C. The following standards contain provisions which, through reference in this text, constitute provisions Principle of this International Standard. At the time of publi- cation, the editions indicated were valid. All standards A known mass of filtered LPG sample is concentrated are subject to revision, and parties to agreements by evaporation. The concentrate is transferred into an based on this International Standard are encouraged evaporation flask using dichloromethane (methylene to investigate the possibility of applying the most re- chloride) and then evaporated by means of a rotary cent editions of the standards indicated below. evaporator. The oily residue remaining after this Members of iEC and iSO maintain registers of cur- evaporation is placed in an oven at 105 °C for 1 h, rently valid International Standards. then cooled and weighed. Is0 3696:1987, Water for analytical laboratory use - Specification and test methods. Reagents ISO4257:1988, Liquefied petroleum gases Method of sampling. 5.1 Acetone, analytical grade. ISO 13757:1996(E) @ISO 6.5 Cooling bath, comprising a 3-dm3 Dewar flask 5.2 Ammonium peroxodisulfate, (NH4S,Og. in three-quarters filied with an appropriate liquid, e.g. sulfuric acid solution. acetone cooled with solid carbon dioxide, to achieve Prepare the necessary volume of solution by dissolv- a temperature below - 60 °C. ing the appropriate quantity (8 g/dm3) of ammonium peroxodisulfate in concentrated suffuric acid (98 % To obtain quickly a cooling bath at the correct tem- minimum purity). perature, introduce approximately 1 kg of solid carbon dioxide into a 3-dm3 beaker and slowly pour in CAUTION Sulfuric acidandammonium acetone. Transfer the cooled acetone into the Dewar peroxodisulfate are strong oxidizing agents and flask containing approximately 200 g of solid carbon therefore contact with organic materials should dioxide. Repeat the operation until the desired volume be avoided. Wear goggles, gloves and safety is obtained. apron, all made from appropriate materials, dur- Such a bath can maintain a temperature below ing all handling operations. NOTE2 - 60 ° for several hours. 5.3 Solid carbon dioxide, for the cooling bath. 6.6 Thermometer, capable of measuring a tem- 5.4 Dichloromethane, analytical grade, containing perature of