Vial handling system with improved mixing mechanism
A vial autosampler includes a vial cup adapted to contain a vial with a stir member inside. The vial autosampler includes a vial mixing system for agitating the contents of the vial. The mixing system has an actuator, such as a motor, and a mixing hub that is coupled to the actuator. The mixing hub includes at least one magnetic field source disposed to rotate a magnetic field about the vial cup.
1. In a vial auto sampler having a vial cup adapted to contain a vial having a stir member therein, a vial mixing system comprising:
an actuator; and
a mixing hub operably coupled to the actuator and having at least one magnetic field source disposed to rotate a magnetic field about the vial cup at a rotational speed that varies as a function of angular position.
2. The system of claim 1 , wherein the actuator is a rotary motor.
3. The system of claim 2 , wherein the actuator is coupled to the hub by a belt.
4. The system of claim 1 , wherein the at least one magnetic field source rotates about the vial.
5. The system of claim 1 , wherein the at least one magnetic field source comprises a pair of magnets.
6. The system of claim 1 , wherein the at least one magnetic field source comprises a rectangular magnet.
7. The system of claim 1 , and further comprising at least one fin mounted to the mixing hub to generate airflow with respect to the vial cup during rotation.
8. The system of claim 1 , and further comprising a thermoelectric device couplable to the vial cup.
9. The system of claim 1 , wherein the at least one magnetic source consists of a single magnet.
10. The system of claim 1 , wherein the hub includes a central passageway to permit needle rinsing.
11. A method of mixing a sample in a vial, the method comprising:
providing a stir member within the vial that is affectable by a magnetic field;
generating a magnetic field proximate the stir member; and
rotating the magnetic field about the vial at a rotational speed that varies as a function of angular position.
12. The method of claim 11 , wherein the rotational speed is varied as a periodic function of angular position.
13. The method of claim 12 , wherein the periodic function is a sine function.
14. The method of claim 11 and further comprising generating airflow around the vial.
15. The method of claim 11 , wherein rotating the magnetic field about the vial includes rotating a magnetic source about the vial.
16. The method of claim 11 , and further comprising:
raising the vial while the magnetic field rotates about the vial.
17. The method of claim 11 , and further comprising:
lowering the vial while the magnetic field rotates about the vial.
18. A vial autosampler comprising:
means for storing vials;
means for moving vials from the means for storing vials to a means for analyzing samples; and
means for rotating a magnetic field about at least one of the vials at a rotational speed that varies as a function of angular position.