7
$\begingroup$

Is there any way that i can detect lead in gasoline, not by sending of to a lab but to be able to do this by myself?

$\endgroup$
5
  • 2
    $\begingroup$ Why do you suspect that there is lead in your gasoline? In most countries, the use of tetraethyl lead was banned more than a decade ago. $\endgroup$ Apr 28 '15 at 10:50
  • $\begingroup$ Certainly tetraethyl lead is banned, but in principal, there could still be some contamination. I don't know about levels after refining, but consider that raw petroleum comes out of the ground and carries all sorts of chemical species along. $\endgroup$ May 13 '15 at 3:35
  • $\begingroup$ Personally, I think it's an interesting at-home analytical chemistry question. $\endgroup$ May 13 '15 at 3:36
  • $\begingroup$ @GeoffHutchison You're certainly right on the composition of raw petrol, but I's assume that the main source of lead in refined petrol were tetraalkyl lead compoundds deliberately added as anti-knocking agents. $\endgroup$ May 13 '15 at 4:00
  • $\begingroup$ I think by volumetric analytic test you can determine by yourself but you need basic lab instrument. BTW I don't know how but according to this book it is possible. $\endgroup$
    – Freddy
    May 13 '15 at 5:58
7
$\begingroup$

As pointed out in my earlier comment, you won't find tetraalkyl lead compounds in current petrol used for cars. In most countries, it was banned decades ago and replaced by MTBE.

However, the situation seems to be different for fuels used in aviation, such as AvGas 100 where lead concentrations up to $\mathrm{1\,g\,L^{-1}}$ can be found.

Even the low lead variant, AvGas 100LL contains $\mathrm{0.56\,g\,L^{-1}}$ lead, see product specifications from TOTAL.

In an older technical note by R. E. Mansell and T. A. Hiller, published in Anal. Chem., 1973, 45, 975-975 (DOI), a possible approach for the decomposition of tetraethyl lead and subsequent detection of $\ce{Pb^{2+}}$ is outlined, referring to the ASTM D526-56 method:

[…] recommends refluxing 50 ml of gasoline with 50 ml of $\ce{HCl}$ for 30 minutes to decompose the tetraethyllead.[…]

In the aqueous layer, $\ce{Pb^{2+}}$ can be detected by complexometric titration with EDTA, either directly, or by back titration with a solution of a $\ce{Mg^{2+}}$ salt.

$\endgroup$
2
  • 1
    $\begingroup$ That's a lot of lead O.o $\endgroup$ May 13 '15 at 4:11
  • $\begingroup$ @Martin-マーチン Yes, I was surprised too! $\endgroup$ May 13 '15 at 4:20
0
$\begingroup$

Try to use aqueous sodium chloride. The lead in the gasoline will with the chloride ion to form lead chloride with is unsoluble white percipitate.

$\ce{Pb^{2+} + 2Cl^- -> PbCl_2}$

$\endgroup$
2
  • 1
    $\begingroup$ Lead ion may react with chloride ion to form lead chloride, but (1) lead chloride is somewhat soluble in water, and (2) tetraethyl lead, the form of lead added to gasoline, will not likely react with chloride ion. But I think this is an interesting question. Kudos for trying to answer it. $\endgroup$
    – iad22agp
    Apr 28 '15 at 13:11
  • 2
    $\begingroup$ Use iodine instead then it is almost completely insoluble $\endgroup$ Apr 28 '15 at 16:28

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.