Chemistry: analytical and immunological testing – Metal or metal containing – Organometallic compound determined
Patent
1990-05-07
1991-08-13
Hill, Jr., Robert J.
Chemistry: analytical and immunological testing
Metal or metal containing
Organometallic compound determined
422 56, 422 58, 422 61, 436 81, 436169, G01N 2178, G01N 3320
Patent
active
050396188
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a swab and a method of using the swab in a test for certain chemical elements, and more particularly, the present invention relates to a swab for retaining test reagents, a method of using the same in a test for metals or other specific elements or compounds, and a method of making the same.
BACKGROUND OF THE INVENTION
Contamination of the environment has been increasing steadily for years as the use of metals, chemicals, pesticides, and bacterial organisms has increased. Even though the toxicity of various metals has been known for centuries, it is only recently that there has been a serious increase in interest in minimizing human exposure to such metals. Current public awareness of such pollutants and their associated hazards has created a consumer demand for products that are capable of determining the presence of unwanted and potentially dangerous materials.
Some of the more toxic metals include lead, cadmium, mercury, barium, chromium and beryllium. Lead, in particular, has been subject to much attention due to its presence in articles or paints commonly found in the home. See, for example, "A Simple Direct Estimation of Ultramicroquantities of Lead in Drinking Water Using Sodium Rhodizonate" by E. Jungreis and M. Nechama, Microchemical Journal, vol. 34, pp. 219-221 (1986); U.K. Patent Application No. 2 025 047 A; "A Simplified Method for Detection of Lead Contamination of Soil" by J. Preer and G. Murchison, Jr., Environmental Pollution (Series B), vol. 12, pp. 1-13; and "A Spot Test for Detection of Lead in Paint" by J. Sayre and D. Wilson, J. Pediatrics. vol. 46, pp. 783-785 (1970).
As the titles of some of the prior art publications indicate, there is a recognized need in the industry for a simple or simplified test or method for determining the presence of lead. However, as will become apparent from the remaining descriptions of the prior art, prior to the present invention, an effective and simple test for lead had not been developed.
In a popular prior art method of detecting lead in paint, sodium sulfide (Na.sub.2 S) is reacted with lead to form lead sulfide (PbS), a black precipitate. The presence of lead is thus confirmed by the appearance of the black precipitate, lead sulfide. This method has several disadvantages: (1) the sodium sulfide is potentially toxic, especially to young children; (2) the black precipitate is difficult to see on dark surfaces; (3) the sodium sulfide releases volatile hydrogen sulfide (H.sub.2 S), which has a noxious odor; and (4) the reagents react with many cations to form black precipitates and thus tends to give false readings on many metallic surfaces.
Another common analytical reagent is a metal complexing agent, rhodizonic acid. For over forty years, rhodizonic acid and salts thereof have been used as analytical reagents to detect heavy metals, including lead, in both qualitative and quantitative analyses. The methodology for using rhodizonate dye is based on two types of tests: spectrophotometer to obtain quantitative information; and reagent.
In addition, semi-quantitative information can be derived from the use of columns packed with silica gel impregnated with rhodizonate dye. See U.K. Patent Application No. 2 025 047 A.
The Macherey-Nagel Company (Duren, Federal Republic of Germany) manufactures a test paper for the determination of lead under the trademark PLUMBTESMO. The PLUMBTESMO strips comprise a heavy filter paper with a reagent impregnated therein. To test for lead in a solution, a strip is dipped into the solution, and observed for a color change that indicates the presence of lead. The PLUMBTESMO strips can also be used to detect lead deposits in motor vehicle tailpipes.
The instruction sheet that is distributed with the PLUMBTESMO strips indicates that the PLUMBTESMO strips may be used to detect the presence of lead on a degreased surface. However, the instruction sheet impliedly recognizes that the PLUMBTESMO strips are not entirely satisfactory for testing for the presence of lead on a surf
REFERENCES:
patent: 3446596 (1969-05-01), Salivar et al.
patent: 3509872 (1970-05-01), Truhan
patent: 4094967 (1978-06-01), Gilbert
patent: 4707450 (1987-11-01), Nason
patent: 4770853 (1988-09-01), Bernstein
patent: 4824789 (1989-04-01), Yafuso et al.
patent: 4873197 (1989-10-01), Gould
P. Elving et al, "Chemical Analysis", 1985, pp. 45-49, 112-113.
Allied Fisher Scientic, "Fisher 86", pp. 496-497, (1985).
Hill Jr. Robert J.
HybriVet Systems, Inc.
LandOfFree
Test swab cartridge type device and method for detecting lead an does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Test swab cartridge type device and method for detecting lead an, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Test swab cartridge type device and method for detecting lead an will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1527036