Abstract: A method and sample holding assembly are described for use in the preparation of samples for analysis. The method comprises the steps of collecting a sample in a concentration tube which is open at one end and closed at the other, the closed end being selectively openable. A vial is coupled to the open end, the tube is inverted, the closed end is opened, and then solvent is evaporated from the sample via the opened end until the concentrated sample is confined to the vial. A sample holding assembly for use in the present method is also described. It comprises a concentration tube, and an adaptor arrangement for coupling a vial to the open end of the tube and defining a fluid path between the tube and the vial.

Abstract: A method and sample holding assembly are described for use in the preparation of samples for analysis. In known techniques, following concentration of a sample using an evaporator, the concentrated solution is manually transferred to a smaller vial compatible with analysis apparatus using a pipette. This leads to loss of the sample and risks cross-contamination. Using the present method, a sample is concentrated directly into the vial. The method comprises the steps of collecting a sample in a concentration tube which is open at one end and closed at the other, the closed end being selectively openable. A vial is coupled to the open end, the tube is inverted, the closed end is opened, and then solvent is evaporated from the sample via the opened end until the concentrated sample is confined to the vial. A sample holding assembly for use in the present method is also described.

Abstract: A centrifugal evaporator includes a chamber in which sample containers are carried and rotated by a rotor and are pivotally mounted so as to swing up to a substantially horizontal orientation as the rotor rotates. The evaporator includes an infra-red source to direct infra-red radiation towards the rotor and the sample containers carried thereon, to heat at least the latter and any sample material therein. A non-contact temperature sensing infra-red pyrometer having a sensor with a defined field of view is mounted in the chamber, such that while the rotor as such is substantially out of its field of view, each sample container at least partly occupies the pyrometer field of view for a part of each rotation of the rotor. The positions of the infra-red source and the pyrometer components are selected so that the radiation from the infra-red source does not impinge on the pyrometer sensor.

Abstract: A method of controlling the pressure within a chamber (12) of a drying apparatus (10) from which air and vapour is removed by a pump (30), which is operated continuously during the drying process. If both of a vent valve (18) and a pressure control valve (32) is opened, air at atmospheric pressure is drawn by the pump (30) directly from the pressure control valve (32), and via the chamber (12) and a non-return valve (26) from the vent valve (18). When the pressure in the chamber (12) is to be reduced both vent and pressure control valves (18, 32) are closed to allow the pump (30) to remove air, gas and vapor from the chamber (12) via the non-return valve (26). After a required chamber pressure has been reached, the pressure control valve (32) is opened while the vent valve (18) remains closed.

Abstract: A method of controlling the pressure within a chamber (12) of a drying apparatus (10) from which air and vapour is removed by a pump (30), which is operated continuously during the drying process. If both of a vent valve (18) and a pressure control valve (32) is opened, air at atmospheric pressure is drawn by the pump (30) directly from the pressure control valve (32), and via the chamber (12) and a non-return valve (26) from the vent valve (18). When the pressure in the chamber (12) is to be reduced both vent and pressure control valves (18, 32) are closed to allow the pump (30) to remove air, gas and vapour from the chamber (12) via the non-return valve (26). After a required chamber pressure has been reached, the pressure control valve (32) is opened while the vent valve (18) remains closed.

Abstract: A centrifugal evaporator is described comprising a chamber in which sample containers are carried and rotated by a rotor and are pivotally mounted so as to swing up into a horizontal attitude as the rotor rotates. The evaporator includes an infra red source to direct infra red radiation towards the rotor and the sample containers carried thereon, to heat at least the latter and any sample material therein. A non-contact temperature sensing infra red pyrometer having a sensor with a defined field of view is mounted in the chamber, such that while the rotor as such is substantially out of its field of view, each sample container at least partly occupies the pyrometer field of view for a part of each rotation of the rotor. The positions of the infrared source and the pyrometer components are selected so that the radiation from the infra red source does not impinge on the pyrometer sensor. In particular the infra red source radiation predominantly impinges on the sample containers rather than the rotor.

Abstract: A method of controlling a centrifugal evaporator in which materials in solution are to be evaporated by rotation in an evacuated evaporation chamber. The method prevents bumping and therefore cross contamination as between one solvent and another in the chamber. Thus prior to centrifuging and reducing the chamber pressure, temperature within the chamber is sensed and a first warning signal is generated if the sensed temperature is greater than a stored temperature value associated with the most volatile solvent component present in the chamber. The first warning signal provides a warning to an operator, and typically inhibits operation of the evaporator. Cooling of the chamber can follow a first warning signal. Data entry means is provided for entering data identifying the solvents in use, and a computer is programmed to compare the entered data with data in a look-up table defining the safe temperatures for different solvents, to identify the safe temperature at which evacuation can begin.