초록 ▼

A method is described for evaporating liquid samples contained in sample holders mounted within a chamber and rotated by the rotor during an evaporation process in which the pressure in the chamber is reduced below atmospheric and the sample holders are rotated at high speed so as to exert centrifug

A method is described for evaporating liquid samples contained in sample holders mounted within a chamber and rotated by the rotor during an evaporation process in which the pressure in the chamber is reduced below atmospheric and the sample holders are rotated at high speed so as to exert centrifugal force on the contents of the holders. Heat is supplied to elevate the temperature of the liquid component of the samples to assist in the evaporation process. The temperature of the sample material is continuously or regularly monitored during the evaporation process and temperature signals are transmitted to a remote computing means which is programmed to generate a control signal for controlling the supply of heat to the samples and controlling the evaporation process. The temperature may be sensed by a probe in a sample holder containing an evaporating liquid sample, or in an adjoining sample holder containing a buffer liquid. The rotational speed is also sensed and a speed signal conveyed to the computing means. In an alternative method the rate of flow of vapor from the chamber is monitored and a flow rate signal is computed which is also supplied to the computer means and the evaporation process is controlled in relation to the value of the vapor flow rate signal. Improved methods of heating and means for supporting sample holders which are to be heated, to achieve more uniform heating thereof, within an evaporating chamber, are described. Apparatus for performing the various methods is also described.

대표청구항 ▼

The invention claimed is: 1. A method of evaporating liquid samples contained in at least some of a plurality of individual sample holders which are mounted within a vacuum chamber and rotated during the evaporation process so that centrifugal force is exerted on liquid contained therein during the

The invention claimed is: 1. A method of evaporating liquid samples contained in at least some of a plurality of individual sample holders which are mounted within a vacuum chamber and rotated during the evaporation process so that centrifugal force is exerted on liquid contained therein during the evaporation process, comprising the steps of supplying heat to the sample holders to heat the liquid therein while a pressure below atmospheric is maintained in the chamber, locating a temperature sensing device in or adjacent at least one of the sample holders for rotation therewith to sense the temperature therein at least during the evaporation process, generating an electrical data signal which is proportional to the sensed temperature, and conveying the temperature data signal via a signal path to electronic data signal processing means. 2. A method as claimed in claim 1 wherein the data signal processing means is located at the centre of rotation of the plurality of sample holders. 3. A method as claimed in claim 1 wherein the processing means converts the output of the sensor into a suitable form for transmission to an external receiver. 4. A method as claimed in claim 3 wherein the processing means converts the sensor output signals into digital signals by which a carrier signal is modulated to effect the said transmission. 5. A method as claimed in claim 3 wherein the processing means converts the sensor output signals into analogue signals by which a carrier signal is modulated to effect the said transmission. 6. A method as claimed in claim 3 wherein the transmitted signal constitutes a radio signal. 7. A method as claimed in claim 6 wherein the radio signals are transmitted to a receiver located externally of a housing for said electronic data signal processing means by means of an antenna which is located externally of the housing and is connected to the signal processing means by means of a conductor which is passed through the housing wall via an insulating seal serving as a lead through. 8. A method as claimed in claim 6 wherein the chamber wall does not readily transmit, or significantly attenuates radio signals, and the radio signals from the signal processing means are received by a stationary radio receiver located within the chamber and conveyed either as radio signals or after demodulation as data signals indicative of the temperature of the sensor, via a conductive path which extends sealingly through and is insulated from the chamber wall. 9. A method as claimed in claim 8 wherein the signals are conveyed through the chamber wall as radio signals for demodulation to produce the said data signals outside the chamber. 10. A method as claimed in claim 4 wherein the carrier signal is a beam of light and the modulation is such as to modulate the intensity of the beam. 11. A method as claimed in claim 10 wherein light signals are transmitted through a window which is light transmitting and which forms an integral part of the housing wall, to enable the modulated light beam to pass to a stationary light responsive device located externally of the housing and which is adapted to convert the received light signals into data signals indicative of the temperature of the sensor. 12. A method as claimed in claim 4 wherein the data signal is employed to drive an indicator which is calibrated to indicate sample temperature. 13. A method as claimed in claim 3 wherein the data signal is employed to control the source of heat heating the sample holders in the chamber. 14. A method as claimed in claim 1 wherein power for the processing means is derived from a battery located within a housing within which the processing means is also located. 15. A method as claimed in claim 14 wherein the battery is connected to the processing means by the closing of a motion sensitive switch which closes when the chamber rotates and is disconnected therefrom by the opening of the switch when the chamber ceases to rotate. 16. A method as claimed in claim 1 wherein power for the processing means is transmitted from a source external to the said housing, to a receptor located within the housing which is connected to the processing means. 17. A method as claimed in claim 1 wherein power for the processing means is supplied thereto from an external power source by means of a rotational electrical connection. 18. A method as claimed in claim 17 wherein the rotational electrical connection comprises slip rings and conductive elements in contact therewith. 19. A method as claimed in claim 17 wherein the rotational electrical connection is separated from vapours in the chamber by being located outside the chamber, or inside the signal processing means housing, and seals are provided around conductors leading between the signal processing means and the external electrical connection where they pass through the wall of the chamber or the housing. 20. A method as claimed in claim 17 wherein at least one of the conductors leading between the processing means and the external rotational electrical connection, extends through the hollow interior of a drive shaft which itself extends through a seal in the chamber wall and serves to rotate both the sample holders and the said housing within the chamber. 21. A method as claimed in claim 20 wherein the drive shaft is electrically conductive and serves as one of the conductive paths for the power to the signal processing means. 22. A method as claimed in claim 16 wherein a material for the said housing is selected which is non-conductive as well as being inert in the presence of the vapours given off during the evaporation process. 23. A method as claimed in claim 22 wherein the material selected for the said housing is polypropylene. 24. A method as claimed in claim 16 wherein the power for the signal processing means is generated in a winding which rotates with the housing relative to a stationary magnetic flux. 25. A method as claimed in claim 24 wherein the winding is wound on soft magnetic material such as is employed to make transformer laminations. 26. A method as claimed in claim 23 wherein the magnetic flux is produced by at least one permanent magnet, which comes into close proximity with the said winding during each rotation of the sample holder, and is located either inside the chamber and the winding is in, or on, or close, to the housing, or is located outside the chamber and the winding is rotated around the internal of the chamber close to the wall thereof. 27. A method as claimed in claim 26 where the magnet is inside the chamber, and a protective coating is applied to the magnet to prevent it coming into contact with corrosive vapours in the chamber. 28. A method as claimed in claim 1 wherein the sensor is sheathed in an impervious inert material so that it will not contaminate the sample or suffer corrosion. 29. A method as claimed in claim 1 wherein the sensor is a thermocouple. 30. A method as claimed in claim 1 wherein the sample holders are rotated at a speed of between 500-3000 rpm depending on g-force required and radius at which the samples are rotated. 31. Method as claimed in claim 1 wherein the heat source is a source of infra-red radiation. 32. Method as claimed in claim 31, in which a heat absorbing screen is located between the source of heat and the samples having a plurality of radiation conductive regions therein, each conductive region aligning with the position of one of the samples in the array of samples, and the thermal transmissivity of the regions increases towards the centre of the array so that samples located in the central region of the array receive more radiation per unit time than those in peripheral regions of the array. 33. Method as claimed in claim 1, wherein the samples are contained in wells in a microtitre plate. 34. A method as claimed in claim 1, wherein the samples are contained in an array of tubes, bottles or vials held in holders which uniformly swing upwardly from a vertical position to a generally horizontal position during rotation of a platform on which they are mounted. 35. A method as claimed in claim 1, wherein the source of heating is situated at one radial position relative to the axis of rotation of the sample containers, and each sample is subjected to radiant heat energy as it passes the source of heat during its rotation around the said axis of rotation. 36. A method of heating as claimed in claim 1, wherein the source of heat extends around an arcuate path extending around some or all of the circular path of the samples. 37. Centrifugal evaporation apparatus comprising a vacuum chamber, a plurality of sample holders for containing liquid samples to be evaporated, said sample holders being rotatably mounted in said vacuum chamber, heating means for heating the sample holders and therefore the liquid samples therein, temperature sensitive probe means located in or adjacent at least one of the sample holders for rotation therewith, and signal path means for conveying electrical data signals proportional to the sensed temperature from the probe means to electronic data signal processing means. 38. Apparatus as claimed in claim 37 in which said signal processing means is located within the chamber and further comprising a transmitting device also within the chamber for transmitting signals to a remote receiver outside the chamber, signals from the signal processing means being employed to modulate the transmitted signal so that when decoded by the remote receiver, the latter will provide a signal containing information about the temperature of the probe. 39. Apparatus as claimed in claim 38 in which the signal processing means is housed in a leak-tight housing to protect the electronic components making up the processing means from pressure fluctuations and from the vapours arising from evaporation in the chamber. 40. Apparatus as claimed in claim 38 further comprising an indicating means calibrated to indicate temperature, and controlled by signals decoded by the remote receiver, to indicate the temperature of the probe. 41. Apparatus as claimed in claim 38 further comprising a heating means in the chamber for heating the sample holders whose heat output is controlled by the magnitude of an electrical current, and current controlling means is provided adapted to control the said electric current to the heating means, and the decoded signal from the remote receiver containing the temperature information is employed to control the current controlling means and thereby the heat output from the heating means and in turn the temperature to which the probe and therefore the liquid samples are permitted to rise. 42. Apparatus as claimed in claim 38 further comprising a battery for powering the signal processing means which may be located inside or outside the housing containing the said processing means. 43. Apparatus as claimed in claim 38 further comprising a power supply which remains stationary and is external to the housing containing the signal processing means together with a path between the power supply and the processing means for conveying power thereto as the housing rotates relative to the power supply. 44. Apparatus as claimed in claim 38 further comprising means within the chamber but external to the housing which generates a stationary magnetic field, and by the provision of coil means which rotates with the housing and which is linked by the said magnetic flux and which moves relative to the flux as the housing rotates relative to the chamber, thereby to induce a current in the winding which is available to power the signal processing means, and an electrical connection is provided between the coil and the power supply circuit in the housing.