2
$\begingroup$

Some of my friends are in Flint and I'm horrified by their situation. I would like to learn how to test for lead independently.

After all if you can't trust the state sending them water to test is not sufficient. The testing procedures I have read about give too many type II errors. A procedure with a bias toward type I errors would be better since then I could pay a professional lab to see if it was real.

For tests that only detect high levels of lead, could they be made more sensitive by evaporating the water then testing a larger sample?

$\endgroup$
  • 7
    $\begingroup$ The situation in Flint doesn't need more gasoline on the fire. A water sample needs to go to a laboratory with appropriate credentials to do water analysis. This is absolutely not a situation for some novice chemist. $\endgroup$ – MaxW Jan 21 '16 at 18:21
  • 1
    $\begingroup$ As far as I understand the problem is not the low quality water getting into your house (bad enough on its own), but possibly lead pipes within your house. I wonder if there is a way to inject some detecting agent at the location where the municipal water enters, something that attaches to lead pipes, and check how much of it is still there when the water gets out of the tape in your kitchen. $\endgroup$ – Gyro Gearloose Jan 22 '16 at 18:33
5
$\begingroup$

I used to work in an environmental water testing laboratory. The regulatory standard method for testing for lead in water uses an Atomic Absorption (AA) spectrophotometer.

It seems that the issue with Flint's water appears to be that the new source of water is corrosive, the water has not been treated for corrosion, and pipes in Flint are commonly made out of lead. So if your pipes at home are made of lead and are corroding, you may have a problem that the lab at the water treatment plant was not able to test for.

If you are curious about checking your water at home, you can obtain a water testing kit from a local hardware store. These kits come with test strips that allow you to check your water for things like nitrates, pH, alkalinity, hardness etc. Make sure your kit allows you to test for lead.

$\endgroup$
  • $\begingroup$ I would doubt that a home water testing kit could detect lead at ppb levels. It might include a test to detect lead solder on copper water pipes since there is always excess solder on the outside of the joints. $\endgroup$ – MaxW Jan 21 '16 at 20:37
  • $\begingroup$ Apparently, they can. From the first lead test kit specification that pops up on Amazon: "Lead kit can detect dissolved lead at levels below the EPA Action level of 15 parts per billion (ppb)" $\endgroup$ – CCovey Jan 21 '16 at 20:48
  • $\begingroup$ Could you post a link to the product? I tried to find the result you mentioned, but I guess Amazon is customizing search results, because I couldn't find it at all. Best I could find was a kit which claimed to detect at 5 ppm (1000x higher, and probably not too helpful). $\endgroup$ – chipbuster Jan 21 '16 at 23:29
  • $\begingroup$ Ok, I don't personally think it is kosher to post direct links to sites advertising products, but here is an example of a lead test kit that meets the specifications above. $\endgroup$ – CCovey Jan 22 '16 at 0:05
1
$\begingroup$

Testing for trace minerals is quite tricky and the procedures can be elaborate if done by chemical means. Note that the lead will generally be in the form of a soluable compound like lead acetate, or lead carbonate or whatever. In many cases other chemicals, especially chlorine, if they are present can interfere with obtaining accurate results. If you go to NIST's web site, you can probably find the standard procedures (which is what the labs do). Doing these procedures probably requires a well-equipped lab, and also probably takes a considerable amount of skill and practice. You can't just read a few instructions and get it right off the bat if you are not an expert chemist.

There are two alternatives:

XRF machines. They cost $30,000 and up. Check with a manufacturer to find out their senstivity.

Spectrographic analysis. If you can obtain access to a high-quality spectrometer, you can easily do a test. It may require some filtering. Just tell the physicist who runs the spectrometer that you want to test for trace amounts of the compounds you are interested in (lead carbonate, etc). This kind of instrument can identify very tiny amounts of any element or compound reliably.

$\endgroup$
  • 3
    $\begingroup$ I was an XRF specialist. XRF isn't going to be able to measure Pb in ppb levels in a water sample. ICP could do this easily, but it is a very expensive instrument. $\endgroup$ – MaxW Jan 21 '16 at 18:47
  • $\begingroup$ @MaxW I think you evaporate the water first before using the XRF. Only the solid residues of the water are tested. $\endgroup$ – Shaka Boom Jan 21 '16 at 18:53
  • 1
    $\begingroup$ I did XRF for years - both WDXRF and EDXRF. Evaporating to solid residues won't work. XRF just isn't the way to do this analysis. This is exactly why some novice chemist shouldn't be trying to do lead water analysis. This needs to be done by a lab certified to do such analyses using a standard technique. $\endgroup$ – MaxW Jan 21 '16 at 19:26
0
$\begingroup$

It’s possible to purchase an instantaneous lead water test kit in Home Depot, Lowes, Ace, or another home improvement, retailer. Test kits may also be bought from internet retailers, such as Amazon or eBay. To know more how to test lead in the water you can also read this article for better understanding.

$\endgroup$
-1
$\begingroup$

A spectrophotometric method would be the cheapest available method, however, the lead would have to be dissolved using a complex ion formation that has a distinct color or absorption pattern that would be is difficult to figure out. There is a commercial lead test that does this, from the Hach Company, but the extraction method requires specific reactants and procedures that I am not versed on.

$\endgroup$

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.