IP 30: Detection of mercaptans, hydrogen sulfide, elemental sulfur and peroxides - Doctor test method

Document options


EI Technical Partners get free access to publications. You will need to Login or Register here

  • Method adopted/last revised: 2007
  • Method reapproved: 2014
  • REF/ISBN: IP030-2936900
  • Status: Current
  • First printed in STM books: April 2007

Scope
The Standard describes the 'Doctor' test for detecting the presence of mercaptans (thiols), hydrogen sulfide, elemental sulfur and traces of peroxides, see note 1, in automotive fuels, kerosines, and other middle distillate petroleum products.

NOTE 1 - The presence of a number of substances in the test sample can affect the result of the test.

Peroxides

This method cannot be used if there are more than trace amounts of peroxides in the test sample.

Carbon disulfide

If the test sample contains more than 0,4% (m/m) of sulfur as carbon disulfide it causes a darkening of the aqueous layer on standing and caution is necessary to avoid confusing this darkening with the immediate blackening due to hydrogen sulfide or that produced by mercaptans.

Phenolic substances

Certain phenolic substances (which may have been introduced as inhibitors) cause colouration of the aqueous layer and if their presence is suspected, a blank test with sodium hydroxide solution in place of the sodium plumbite solution should be carried out first for the purpose of comparison, see 6.1.

Members Benefits

Are you an EI Member? If yes, register/log in now to ensure you receive free access or discounts to EI publications. How to do this:

1. Sign up/register with this site.

2. Log in

3. Link your membership details to your profile, on your profile page.

If you are not a Member, why not join today and receive all of the benefits of EI Membership? EI Members are entitled to a 25% discount on most EI publications.