Flowable dry powder composition

Patent metadata

Field	Value
Publication number	US-9310310-B2
Application number	US-201213534030-A
Country	US
Kind code	B2
Filing date	Jun 27, 2012
Priority date	Aug 26, 2011
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

A flowable dry powder composition comprising a mixture of diphenylcarbazide particles and glass bubbles; kits containing such compositions; methods of filling containers with such compositions; and, methods of using such compositions in the detecting of hexavalent chromium.

First claim

What is claimed is:

1. A flowable dry powder composition comprising a mixture of diphenylcarbazide particles and hollow glass bubbles wherein at least 5% of the glass bubbles by weight are in the form of broken shards.

2. The composition of claim 1 wherein the glass bubbles are made of soda-lime borosilicate glass.

3. The composition of claim 1 wherein the glass bubbles comprise a 50 th percentile particle size in the range of about 30 microns to about 65 microns.

4. The composition of claim 1 wherein the glass bubbles comprise an oil absorption of from about 0.2-0.6 grams oil per cc of glass bubbles.

5. The composition of claim 1 wherein the glass bubbles comprise a true density of from about 0.1 g/cc to about 0.3 g/cc.

6. The composition of claim 1 wherein the composition consists essentially of a mixture of diphenylcarbazide particles and glass bubbles.

7. The composition of claim 1 wherein the composition consists of a mixture of diphenylcarbazide particles and glass bubbles.

8. The composition of claim 1 wherein the composition is inside a sealed container.

9. The composition of claim 8 wherein the sealed container is a breakable container.

10. The composition of claim 9 wherein the breakable sealed container is within a secondary container.

11. The composition of claim 10 wherein the secondary container additionally contains a buffer solution.

12. A kit for detecting hexavalent chromium, comprising:
at least one disposable swab comprising a secondary container that contains:
a breakable container containing a flowable dry powder composition comprising a mixture of diphenylcarbazide particles and hollow glass bubbles wherein at least 5% of the glass bubbles by weight are in the form of broken shards,
and,
a buffer solution.

13. The kit of claim 12 wherein the breakable container is a sealed breakable container and wherein the secondary container further comprises a breakable buffer solution container, that contains the buffer solution.

14. The kit of claim 12 wherein the secondary container comprises an open end comprising a liquid-permeable porous member.

15. A method of filling a container with a flowable dry powder composition, the method comprising flowing the flowable dry powder composition of claim 1 into the container.

16. The method of claim 15 further comprising the step of packaging the container within a secondary container that also contains a buffer solution.

17. A method of detecting hexavalent chromium, the method comprising:
mixing the flowable dry powder composition of claim 1 , with a buffer solution to form a detection mixture;
and,
exposing the detection mixture to a sample potentially containing hexavalent chromium.

18. The method of claim 17 further comprising the step of optically interrogating the detection mixture.

Assignees

• Gozum John E
• 3M Innovative Properties Co

Inventors

• Gozum John E

Classifications

• G01N21/78 Primary

  producing a change of colour · CPC title

• G01N31/22

  using chemical indicators (G01N31/02 takes precedence) · CPC title