US5039618A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Test swab cartridge type device and method for detecting lead and cadmium
Assignee: Hybrivet Systems Inc
•
Filing: 1990-02-02
•
Granted: 1991-08-13
•
Expires: 2010-02-02
Abstract
Abstract PCT No. PCT/US90/00527 Sec. 371 Date May 7, 1990 Sec. 102(e) Date May 7, 1990 PCT Filed Feb. 2, 1990.A swab is impregnated with a test reagent such that a test for a specific substance can be effected by rubbing the impregnated swab over the surface to be tested and then viewing the swab for a reagent reaction. A method for testing for a metal includes impregnating a swab with a reagent, such as, for example, a rhodizonate dye reagent when testing for lead, and rubbing the swab over a surface suspected of containing the metal. If a metal is present in the surface, a reaction with the metal produces an easily detectable color on the swab tip.
Inventors
- 👤 Marcia J. Stone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 08:37
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/84; G01N21/00; G01N21/75; G01N21/77; G01N21/78; G01N21/17; G01N21/25; G01N21/29
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
92 words
A method of testing for a substance on a surface with a reagent that reacts with the substance where the substance is lead or cadmium, comprising the steps of: providing a swab stick having a stem and an absorbent ball of material at one end of the stem, wherein the absorbent ball of material is impregnated with the reagent; contacting the impregnated absorbent ball of material with the surface; and detecting the presence of the substance by inspecting the impregnated ball of material for a reaction between the substance and the reagent.
Claim 2
Independent Claim
92 words
A method of testing for a substance on a surface with a reagent that reacts with the substance where the substance is lead or cadmium, comprising the steps of: providing a swab stick having a stem and an absorbent ball of material at one end of the stem, wherein the absorbent ball of material is impregnated with the reagent; contacting the impregnated absorbent ball of material with the surface; and detecting the presence of the substance by inspecting the impregnated ball of material for a reaction between the substance and the reagent.
Claim 3
Dependent Claim
37 words
The method of claim 1, wherein the stem of the swab stick is hollow, and the step of impregnating the absorbent ball includes injecting the reagent through the hollow stem into the center of the absorbent ball.
Claim 4
Dependent Claim
27 words
The method of claim 1, further comprising the step of wetting the absorbent ball of material with a buffer having a pH level conducive to the reaction.
Claim 5
Dependent Claim
12 words
The method of claim 1, wherein the substance tested for is lead.
Claim 6
Dependent Claim
11 words
The method of claim 4, wherein the reagent comprises rhodizonate dye.
Claim 7
Dependent Claim
13 words
The method of claim 5, wherein the reagent further comprises an inert filler.
Claim 8
Dependent Claim
25 words
The method of claim 6, wherein the ratio of filler to rhodizonate dye is within the range of about 20:1 to about 100:1 by weight.
Claim 9
Dependent Claim
26 words
The method of claim 4, wherein the absorbent ball of material is soaked with a solution comprised of rhodizonate dye, an inert filler and a buffer.
Claim 10
Dependent Claim
12 words
The method of claim 1, wherein the substance tested for is cadmium.
Claim 11
Dependent Claim
13 words
The method of claim 9, wherein the reagent comprises 4-nitronaphthalene-diazoamino-azo-benzene or 1-(4-nitrophenyl)-3-(4-phenylazo phenyl)triazene.
Claim 12
Dependent Claim
13 words
The method of claim 10 wherein the reagent further comprises an inert filler.
Claim 13
Independent Claim
75 words
A device for testing for a substance on a surface wherein the substance is lead or cadmium comprising: a cartridge; two compartments within said cartridge wherein one compartment contains a reagent that reacts with the substance and the other compartment contains an activating solution; and an absorbent ball of material mounted at one end of the cartridge, wherein the reagent and activating solution are combined and mixed within the cartridge before the device is used.
Claim 14
Independent Claim
75 words
A device for testing for a substance on a surface wherein the substance is lead or cadmium comprising: a cartridge; two compartments within said cartridge wherein one compartment contains a reagent that reacts with the substance and the other compartment contains an activating solution; and an absorbent ball of material mounted at one end of the cartridge, wherein the reagent and activating solution are combined and mixed within the cartridge before the device is used.
Claim 15
Dependent Claim
15 words
The device of claim 12 wherein each of the two compartments is a breakable cartridge.
Claim 16
Dependent Claim
14 words
The device of claim 12 wherein one of the compartments is a breakable cartridge.
Claim 17
Dependent Claim
10 words
The device of claim 12 wherein the substance is lead.
Claim 18
Dependent Claim
12 words
The device of claim 15 wherein the reagent includes a rhodizonate dye.
Claim 19
Dependent Claim
22 words
The device of claim 15 wherein the activating solution is a buffer having a pH of between about 2 and about 3.
Claim 20
Dependent Claim
10 words
The device of claim 12 wherein the substance is cadmium.
Claim 21
Dependent Claim
12 words
The device of claim 18 wherein the reagent includes 4-nitronaphthalene-diazoamino-azo-benzene or 1-(4-nitrophenyl)-3-(4-phenylazophenyl)triazene.
Claim 22
Independent Claim
56 words
A method for testing for cadmium on a surface comprising: soaking a filter paper with an activator solution, wetting the filter paper with water, placing the filter paper on a surface, placing drops of 4-nitronaphthalene-diazoamino-azo-benzene or 1-(4-nitrophenyl)-3-(4-phenylazophenyl)triazene on the filter paper, and detecting the presence of cadmium by inspecting the filter paper for a pink color.
Claim 23
Independent Claim
56 words
A method for testing for cadmium on a surface comprising: soaking a filter paper with an activator solution, wetting the filter paper with water, placing the filter paper on a surface, placing drops of 4-nitronaphthalene-diazoamino-azo-benzene or 1-(4-nitrophenyl)-3-(4-phenylazophenyl)triazene on the filter paper, and detecting the presence of cadmium by inspecting the filter paper for a pink color.
References Cited (Backward Citations)
US3446596A
Cited
US3509872A
Cited
US4094967A
Cited
DE3618842A1
Cited
US4707450A
Cited
US4824789A
Cited
US4824789B1
Cited
US4770853A
Cited
US4873197A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-12 | 1995-02-11 | 1995-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-12 | 1999-02-11 | 1999-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-12 | 2003-02-11 | 2003-08-13 | $7700.00 | Window Closed / Lapsed |