Abstract:
A magazine-type sample rotation body ( 7 ) is arranged in a high frequency chamber ( 5 ) so that it rotates away from the horizontal, the body ( 7 ) accommodating, in fixed location, reactor blocks ( 10 ) that are sealed or sealable from fluids such that fluids contained in sample vessels in the reactor blocks can be mixed before, during and after high frequency exposure because of the rotational movement of the sample rotation body.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention concerns a device for performing chemical reactions and processes in high frequency fields. 
     It allows the advantageous introduction of energy and carrying out of disintegration, hydrolysis, chemical synthesis, extraction and drying as well as other reactions and processes under the effect of high frequency. 
     2. Description of the Related Art 
     For the running, acceleration and/or initiation of chemical reactions and processes an introduction of energy is often needed. For this purpose the reaction mixtures, are arranged, for example, in a microwave system with a radiation-screened housing in reaction containers that allow microwaves to pass through them, and energy is introduced through radiation with microwaves. Since with the reactions and processes that take place high pressures often result or the reactions only run under pressure, the entire arrangement must be stable under pressure and, for example, have a locking cover system. In general the reaction vessels are also fitted with safety or control devices, in order to be able to monitor the running of the chemical reactions and processes. 
     Equipment arrangements for the introduction of thermal energy in disintegration, hydrolysis, chemical synthesis, extraction, drying and other reactions and processes have been extensively described, but also have the likewise known disadvantages such as long heating and/or reaction times, limited or poor pressure and/or temperature stability and a lack of flexibility of the individual arrangements. Furthermore and as a rule, only reactions and processes in individual vessels, or a small number of parallel reactions, are possible. The stated disadvantages have in part been overcome by the use of high frequency energy to activate chemical reactions and processes, but here also there are limits on the number of sample vessels. Patent DE 43 25 667 A1 describes a device that allows the execution of six, eight or ten reactions simultaneously. Here the sample vessels with the samples are placed individually on a horizontal rotating table, secured to this, and moved on it in the plane of the table through the microwave field. This type of sample preparation requires, compared with the actual reaction time, long set-up times and in many cases involves a danger of misanalysis, since in particular because of the extensive time-consuming sample preparation the waiting times of the individual reaction mixtures can differ greatly. In these cases the assessment of the microwave radiation on the samples is only comparable to a limited extent and in practice can lead to not inconsiderable misinterpretations. The structural shape of the reactor system does not allow automated sample preparation that, with parallel syntheses in particular, leads to a large amount of time spent on sample preparation with high error rates. Genuinely high throughput screening is not possible with these reactor systems for the stated reasons. 
     In Tetrahedron Lett. 1998, 39, 1117-1120 the use of simple multi-corrugated plates in a domestic microwave unit is described. The use of these corrugated reactors for parallel synthesis in the microwave field is, however, associated with technical shortcomings such as a lack of pressure stability, low temperature stability of the reactor materials, poor energy distribution and associated variations in temperatures in the individual reactors as well as consistent temperature and concentration gradients in the individual reaction mixtures. It can be assumed that the stated weak points lead to a number of misconceptions during material screening. 
     SUMMARY OF THE INVENTION 
     The object of the invention is to fashion, with the least possible effort, a practical device with which a number of chemical reactions and processes in high frequency fields can be carried out under an improved and in each case extensively the same high frequency effect on the individual reactions and processes. In particular, misconceptions in material screening that can occur due to sample specifics such as temperature and concentration gradients, as well as shortcomings of the device and its application, should be avoided. 
     The invention envisages a magazine-type sample rotation body in the high frequency chamber arranged so that it rotates away from the horizontal, for the stacked, fixed-location accommodation of liquid- and gas-tight sealed or sealable, or single- or multiple, reaction blocks. These are pushed into the sample rotation body and with this are moved around their axis of rotation in a quasi “overhead” manner. Here the reactor blocks can each be stacked individually in the sample rotation body, or reactor blocks already existing in a stack are introduced and secured simultaneously. With the movement of the sample rotation body the individual samples are mixed in order to generate homogenous and comparable state conditions. Furthermore, the reactor blocks with the samples to be treated with the high frequency radiation and which have been mixed with the movement are transported through the radiation field(s) so that the radiation can have its influence with the same effect on each of the samples that can be present in quantity for simultaneous treatment. Any inconsistencies in the high frequency fields are thus extensively balanced out in terms of their effect on the radiation treatment of the sample in the multiple chemical reactions and processes. A device is fashioned that is loaded with the minimum of effort and in a short time and can be loaded with a number of reaction mixtures, equipped for high frequency treatment with comparable analytical conditions of the individual samples. Although a number of simultaneous sample reactions can be carried out, nevertheless at the start of and during the high frequency effect for the reaction mixtures essentially comparable sample and treatment conditions are guaranteed, so that misanalyses during material screening are extensively excluded. As a result in particular of the short apparatus set-up time (even for many samples, for example due to automatic sample preparation) during high frequency treatment and preparation for this, the analytical drawbacks of differing sample specifics such as temperature and concentration gradients, can to a large extent be avoided. 
     As a result of the advantageous low effort, fast and very practical loading, treatment and removal of a number of samples, the preconditions are created for genuinely high throughput screening. 
     For the reactor blocks preferably sample vessel plates can be used, which in the already known manner exist as corrugated analysis plates with sample vessels incorporated and arranged in a fixed grid or as sample carrier plates with sample vessel inserts. The latter can likewise have the known grid dimension of the sample vessels, so that connection with the advantageous so-called liquid handling technique is possible. The said high throughput screening is also supported by this. 
     Further advantageous structural designs of the characteristics of the independent claim are described and claimed herein. These concern, for example, the acceptance and the liquid-proof sealing of the reactor blocks with the sample vessels. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be explained in more detail in the following using an embodiment that is illustrated in the drawings. These drawings are as follows: 
     FIG.  1 : General view of a microwave treatment system with sample rotation body in the microwave chamber 
     FIG.  2 : Sample rotation body in side view (cutaway view) 
     FIG.  3 : Sample rotation body in axial view (cutaway view) 
     FIG.  4 : Holed plate with vessel inserts as reactor block in the sample rotation body 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 is a schematic view of a microwave treatment system for performing multiple chemical reactions and processes. A high-frequency oven  1 , that is controlled via a controller  2  with a keyboard  3  or mouse  4 , has a microwave chamber  5  with one or more not explicitly shown microwave emitters. The microwave chamber  5  is accessible from the outside via a front flap  6 . In the microwave chamber  5  a sample rotation body  7  is arranged, that runs on a drive controller, which for clarity of the drawing is not shown in FIG. 1, to perform a rotation movement (in principle comparable with a rotating tubular kiln) around an axis  8 . This sample rotation body  7  incorporates a magazine-like reactor system, which when the front flap  6  of the microwave chamber  5  is opened or via a slide  9  can be withdrawn from the microwave chamber  5 . In the withdrawn state of the slide  9  the sample rotation body  7  can be loaded with the reactor blocks in the form of sample vessel plates  10 , which are sealed with silicon PTFE films  11 , or the microwave treated sample vessel plates  10  can be removed from the sample rotation body  7  again. During the microwave treatment of the sample liquid- and gas-tight vessel plates  10  that are fitted in the sample rotation body  7  in a magazine-like manner, these are, as shown by a rotating arrow  12 , moved around the axis  8  of the reactor system in the microwave chamber  5  in a quasi overhead manner. 
     The microwave treatment can be visually monitored via a window  13  in the front flap  6  and thermally via a temperature sensor  14 . 
     FIGS. 2 and 3 show in detail the sample rotation body  7  as a cross-section in the direction of the axis  8  (FIG. 2) and as a cross-section transversally to this (FIG.  3 ). 
     The sample rotation body  7  is supported in a rotating manner via ball or roller bearings  15  on bearing surfaces, not shown in FIG. 2 for the purposes of clarity, of the slide  9  in the microwave chamber  5  to rotate around the axis  8 . To allow its rotational movement, on its rear side (looking from the front flap  6  outwards) a coupling receiver  16  and driving holes  17  are provided as drive elements. 
     In order to accept the sample vessel plates  10  the sample rotation body  7  has an insertion opening  18  (see FIG. 3) with respective guide elements that are not illustrated to set the position, for example guide rails and stops. A design solution would also be conceivable in which the insertion opening  18  is accessible from both sides in the sample rotation body  7 . 
     In this insertion opening  18  in the withdrawn state of the slide  9  (see FIG.  1 ), as shown for example in FIGS. 2 and 3 for three sample vessel plates  10 , one or more sample vessel plates  10  are stacked and retained therein. Here the plates can be introduced one after another or as a stack into the insertion opening  18 . 
     For the sample vessel plates  10  in the embodiment in FIGS. 2 and 3, holed plates  19 , for example in microwave-absorbing plastic, like WEFLON, are shown in whose locating holes  20  vessel inserts  21  are inserted as individual reactor vessels with a set or freely selectable size, preferably in a grid that can be adapted to the liquid handling technique, e.g. 8×12. 
     The vessel inserts  21  can, for example, be secured in the holed plates  19  by pressure or bonding and depending on the design and the application may comprise, by way of example; glass, quartz or plastic. Here they will be introduced in such a way that their top edges are essentially flush with the top edges of the holed plates  19  and thus allow a pressure resistant seal. FIG. 4 shows the detail of such an arrangement of a holed plate  19  with individual vessel inserts  21 , which in each case are closed with a cover  22 , preferably consisting of PTFE, and/or sealed with a common silicon PTFE film  11 . In place of the cover  22  the vessel inserts  21  can also be sealed individually and independently of the silicon PTFE film  11  (for example by film or silicon seal). 
     A pressure-resistant seal of the vessel inserts  12 , which not least also brings about the locking in position for the movement of the sample rotation body  7 , is achieved by means o platens  23 ,  24  pressing against a base plate  25 . In this way the flexible intermediate film layers (silicon PTFE films  11 ) are brought into contact positively and non-positively respectively, on the one hand with the top edges of the holed plates  19  or the vessel insert  21  or their covers, and on the other with the bottom edges of the holed plates  19  or their platen  24 . For the application force a pressure screw  26  that is accessible from the outside; see FIG. 1) is used with a linear spring  27 , which works on the platens  23  and  24 . The apparatus set-up time is limited to the magazine loading and fixing of the sample vessel plates  10  on the sample rotation body  7 . 
     The sample vessel plates  10  (in the embodiment in FIGS. 2-4 holed plates  19  with vessel inserts  21 ) which are in this way secured in position as a stack which is pressure resistant and liquid- and gas-tight in the sample rotation body  7  are, following pushing in of the slide a (see FIG.  1 ), within the sealed microwave chamber  5  and in the sample rotation body  7  moved together around the axis  8  of this through the microwave field, whereby the samples contained in the sample vessel plates  10  with this overhead movement of the sample vessels, are mixed. On the one hand in each of the individual samples homogenous state conditions that are comparable with each other are thus created, and on the other through the localized change of position of the sample vessels any local inconsistencies in the microwave field are to a large extent balanced out. 
     The rotary movement drive of the sample rotation body  7  is symbolized in FIG. 1 by a drive pin  28 , which when the slide  9  is introduced engages in one of the driving holes  17  (see FIG. 2) on the rear of the sample rotation body  7  shown in FIG.  1  and moves this in the direction of the rotating arrow  12 .