System for open and closed vessel microwave chemistry

• US 6,011,247 A
• Filed: 03/02/1998
• Issued: 01/04/2000
• Est. Priority Date: 03/03/1997
• Status: Expired due to Fees

• Current Assignee: Questron Canada Incorporated
• Original Assignee: Questron Canada Incorporated
• Inventors: Grillo, Angelo C., Burgener, Paul E.
• Primary Examiner(s): Paschall, Mark
• Assistant Examiner(s): PWU, JEFFREY C
• Application Number:
  US09/033,021
• Time in Patent Office: 673 Days
• Field of Search: 219/745, 219/686, 219/687, 219/688, 219/679, 219/702, 219/705, 219/707, 219/733, 219/756, 23/23 R, 422/21, 422/113, 422/78, 422/79, 422/119, 422/102, 422/186, 422/99, 422/67
• US Class Current: 219/686
• CPC Class Codes: B01J 19/126 Microwaves
• CPC Class Codes: B01J 2219/0871 Heating or cooling of the reactor
• CPC Class Codes: B01J 2219/0875 Gas
• CPC Class Codes: B01J 2219/0877 Liquid
• CPC Class Codes: B01J 2219/0879 Solid
• CPC Class Codes: B01J 2219/1218 Multiple reactors
• CPC Class Codes: B01J 2219/1227 Reactors comprising tubes with open ends
• CPC Class Codes: B01J 2219/1257 Rotating supports
• CPC Class Codes: B01J 2219/126 in the form of a closed housing
• CPC Class Codes: H05B 6/806 for laboratory use

Abstract

A microwave system is provided which is capable of performing both open and closed vessel microwave chemistry in an efficient and productive manner. For open vessel chemistries, such as digestions, the system offers a microwave oven with: liquid cooled refluxing of samples; reagent dispensing, and temperature control. The open vessel module can quickly and easily be interchanged with a high pressure module capable of operating at pressures in excess of 600 psi.

Claims

1. A method for performing microwave chemistry in open vessels, comprising the steps of:

(a) microwave heating multiple samples in open vessels;

(b) rotating said open vessels of the multiple samples within a microwave oven;

(c) refluxing to contain the multiple samples within said open vessels during the microwave heating process;

(d) reagent dispensing before, during and after microwave application; and

(e) removing fumes during the microwave heating procedure so that microwave chemistry may be performed on the multiple samples contained in said step (c).

2. The method according to claim 1, further comprising the steps of controlling and monitoring the temperature of the multiple samples in said open vessels.

3. The method according to claim 1, further comprising the step of introducing a microwave absorbing liquid into the microwave for cooling the multiple samples in said open vessels by refluxing during the microwave heating process.

4. The method according to claim 3, wherein said microwave absorbing liquid is water.

5. The method according to claim 3, wherein said microwave absorbing liquid flows through a jacketed vessel and a microwave reflecting manifold so that the absorption of microwaves is minimized.

6. An apparatus suitable for microwave chemistry, comprising:

a microwave oven;

a manifold for holding multiple samples contained in sealed high pressure closed vessels and refluxing open vessels, supplying liquid cooling and providing a convenient path for fume exhaustion for said open and closed vessels;

a multiple reagent dispensor for introducing reagents into the microwave oven; and

an exhaust module for removing fumes directly from said open vessels within the microwave oven without contaminating the interior thereof so that microwave chemistry may be performed on the multiple samples contained in said closed vessels and the multiple samples contained in said open vessels.

7. The apparatus according to claim 6, further comprising an infrared thermal processor for monitoring and controlling the temperature applied to the multiple samples.

8. The apparatus according to claim 6, further comprising a reflecting manifold for holding a plurality of vessels and circulating a cooling liquid to remove fumes.

9. The apparatus according to claim 8, further comprising means for removing samples from the microwave oven, changing vessels and switching vessels to another one of the manifolds.

10. The apparatus according to claim 8, further comprising a telescoping mechanism for enabling said reflecting manifold and said plurality of vessels to be easily and quickly fitted in place, removed, and switched in the microwave oven.

11. The apparatus according to claim 6, further comprising a valve controller for supplying cooling liquid at rates consistent with refluxing and at slower rates consistent with evaporation.

12. The apparatus according to claim 11, further comprising an air purger for removing liquid from liquid flow channels while the manifold and said open and closed vessels are placed in the microwave oven.

13. The apparatus according to claim 6, further comprising a processor for monitoring and controlling the microwave chemistry processes performed on the multiple samples.

14. The apparatus according to claim 13, wherein said processor is a personal computer.

15. The apparatus according to claim 6, wherein said open vessels comprise microwave reflecting, cooling liquid flow channels for minimizing the absorption of microwaves by the liquid while absorbing heat from the multiple samples in order to regulate evaporation of the multiple samples.

16. The apparatus according to claim 15, wherein said microwave reflecting, cooling liquid flow channels are disposed at neck or mid-portions of said vessels.

17. The apparatus according to claim 15, further comprising a top piece for dispensing reagents from the microwave oven with minimal splashing, and assisting condensation and returning of the multiple a samples which evaporate and are then cooled by said microwave reflecting, cooling liquid flow channel.