ISO INTERNATIONAL STANDARD 8819 Secondedition 1993-10-01 ANSI Internat Doc Sec Liquefied petroleum gases Detection of hydrogen sulfide --- Lead acetate method Gaz de pétrole liquéfiés -- Détection de I'acide sulfhydrique -- Méthode a I'acétate de plomb ISO Reference number iSO 8819:1993(E) No reproduction or networking permitted without license from IHS Not for Resale ISO 8819:1993(E) Foreword IsO (the International Organization for Standardization) is a woridwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out through Iso technical committees. Each member body interested in a subject for which a technical committee has been establishedhas the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with IsO, also take part in the work. Iso collaborates closely with the International Electrotechnical Commission (lEC) on all matters of electrotechnical standardization. Draft international Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International a vote. international Standard IsO 8819 was prepared by Technical Committee ISO/TC28,Petroleum productsand lubricants. Thissecond editioncancelsand replacesthe first edition (IS0 8819:1987), which has been technically revised. Annex A of this International Standard is for information only. ISO1993 All rights reserved. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without per- mission in writing from the publisher. InternationalOrganizationforStandardization Case Postale 56: CH-1211 Geneve 20: Switzerland Printed in Switzerland ii Not for Resale INTERNATIONAL STANDARD ISO8819:1993(E) Liquefied petroleum gases Detection of hydrogen sulfide - Lead acetate method WARNING - The use of this International Standard may involve hazardous materials, operations 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 3.2 Lead acetate test paper, either prepared by dipping strips of smooth filter paper into an aqueous This International Standard specifies a method for the 50 g/l solution of lead acetate, withdrawing the strips detection of hydrogen sulfide in liquefied petroleum and removing excess solution from them with clean filter paper, or commercially available test paper if it gases. is of a type that has been shown to give simitar re- The lower limit of detectability is 4 mg of hydrogen suits to paper prepared as above. sulfide in 1 m3 of liquefied petroleum gas.'Methyl The strips of the test paper shall be approximately mercaptan,ifpresent,producesatransitoryyellow stain on lead acetate paper which, however, fades 51mmlongby9,5mmwideandhavea3,5mmdi completely in less than 5 min. 'Other sulfur com- ameterholenearto one end.Thishole shall permit pounds present in liquefied petroleum gas do not in- the strip to hang freely in the test apparatus. terfere withthetest. 3.3 Flow indicator, comprising a wet test meter or NOTE1 Liquefied petroleum gases and the products of variable area flowmeter, which measures gas flow their combustion should not be unduly corrosive or reactive rates in the range of 2 I/min to 3 I/min. to materialswith which they come into contact.It isthere- fore important that the presence of any hydrogen sulfide,a Sampling highly reactive substance, be detected. Additionally. the 4 odour of hydrogen suifide is unacceptable in some applica- tions of liquefied petroleum gases (e.g. lighter fuel). Information on constraints to the use of sample con- tainers and to laboratory testing is given in annex A. 2 Principle 5 Procedure The vaporized sample is passed over moist lead 5.1 Connect the test apparatus (3.1) to the sample ac