×

Handwipe disclosing method for the presence of lead

  • US 6,248,593 B1
  • Filed: 12/09/1999
  • Issued: 06/19/2001
  • Est. Priority Date: 06/11/1997
  • Status: Expired due to Term
First Claim
Patent Images

1. A method for the detection of lead on a surface suspected of lead contamination, said method comprising:

  • (a) wiping the surface with a handwipe whereby residue containing lead contamination, if present on the surface, is retained and collected on the handwipe;

    (b) solubilizing any lead collected on the handwipe with an acidic aqueous solution having a pH of about 1 to about 5, wherein the acidic solution is not present on the handwipe during step (a) and, wherein the lead is solubilized on the handwipe;

    (c) treating the solubilized lead with an anion selected from the group consisting of rhodizonate or sulfide; and

    (d) observing the color formed in step (c);

    wherein, if lead is present on the surface, the color formed is pink to red if the anion is rhodizonate or the color is brown to black if the anion is sulfide.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×