Abstract:
A method is provided for the preparation of samples for an analyzer, and a sample preparation station therefor, which allows injection of even relatively large liquid volumes through a packing in an automated manner in order to enrich the packing of the substances of a sample which are to be investigated.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
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   STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not Applicable 
   REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX SUBMITTED ON A COMPACT DISK. 
   Not Applicable 
   BACKGROUND OF THE INVENTION 
   The invention relates to a method for the preparation of samples for an analyzer and to a sample preparation station therefor. 
   For the adsorption and/or sorption of analytes, it is known to use cartridges with packings located therein, through which respective sample material is induced to flow, in order to analyze the analytes qualitatively and/or quantitatively later by means of a respective analyzer, for example by means of a liquid or gas chromatograph. However, this requires complicated manual handling. 
   DE 102 19 790 C1 discloses a handling device for samples for an analyzer, the handling device comprising a gripper which is movable along three axes perpendicular to one another and by means of which different samplers, such as, for example, different syringes and also sample tubes equipped with transporting heads, can be handled. 
   BRIEF SUMMARY OF THE INVENTION 
   According to the invention, a method is provided for the preparation of samples for an analyzer, and a sample preparation station therefor, which allows injection of even relatively large liquid volumes through a packing in an automated manner in order to enrich the packing of the substances of a sample which are to be investigated. 
   A specific embodiment of the invention is a method for the preparation of samples for an analyzer, in particular a chromatograph, wherein a sample discharger is used which is movable between a sample discharge position and an elution position and which comprises a holder for a receptacle, movable and detainable therein, for a cartridge, provided with a packing for the reception of analytes, with a syringe needle, with a sealing and with a transporting head, further wherein a cartridge is inserted into the receptacle of the sample discharger located in the sample discharge position, sample material is injected at least once by means of an injector through the sealing into the cartridge and, after flowing through the packing, is discharged through the first syringe needle, an empty sample container is arranged in the elution position, the sample discharger, together with the laden cartridge, are moved into the elution position, and the receptacle, together with the cartridge, are detained in the holder of the sample discharger, and at least one eluent is injected at least once by means of an injector through the sealing into the cartridge and is discharged through the syringe needle into the sample container, the cartridge, sample container and injector being handled automatically. 
   According to a further embodiment of the invention, a sample preparation station for samples for an analyzer, in particular a chromatograph, comprises a sample discharger which is movable between a sample discharge position and an elution position and which comprises a holder for a receptacle, movable and detainable therein, for a cartridge, provided on the outlet side with a first syringe needle, on the inlet side with a sealing and a transporting head and with a packing for the reception of analytes, at least one injector and at least one automatic handling device, by means of which cartridges, the at least one injector and the sample container can be handled. 
   It thereby becomes possible to use commercially available cartridges with packings or for self-packing as once-only articles, on which analytes can be enriched even out of relatively large liquid volumes in an automated manner. 
   Further embodiments of the invention may be gathered from the following description and the claims. 
   The invention is explained in more detail below with reference to exemplary embodiments illustrated in the accompanying figures. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows an embodiment of a sampling station in cross-sectional view in the form of a detail. 
       FIG. 2  shows in the form of a detail a cross-sectional view, rotated at 90°, through the sampling station of  FIG. 1 . 
       FIG. 3  shows in the form of a detail the sampling station of  FIG. 1  during a conditioning operation. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The sampling station illustrated in  FIGS. 1 and 2  comprises a mount or stand  1  with a slide shaped sample discharger  2  which is movable (or pivotable, not illustrated) via rollers  3  along rails  4  between two positions. One of these positions is used as the sample discharge position and the other as the elution position. Located in the elution position is a trough like container holder  5  for receiving a sample container  8 , in this exemplary embodiment a vial, provided with a cap  7  holding a septum  6 . 
   Expediently, it is provided that the sample collected in the respective sample container  8 , which is in the elution position, can be shaken. For this purpose, it may be provided that the sample container  8  contains a magnetic stirring element, whilst a device generating an alternating magnetic field is arranged below the container holder  5  in order to generate a stirring movement of the stirring element. Stirring or agitation may also be carried out by means of ultrasound. 
   Furthermore, a shaking of the container holder  5  and consequently of the sample in the sample container  8  received by the container holder  5  may be provided. For this purpose, expediently, the container holder  5  is suspended cardanically at its upper end and can be driven via an electric motor  9 . During operation, the electric motor  9  drives a ball  10 , arranged eccentrically on the shaft of the electric motor  9 , at a controlled speed, the ball  10  being arranged in a central hollow journal  11  below the bottom of the container holder  5  and, via its eccentric arrangement, subjecting the container holder  5 , on account of the cardanic suspension at its upper end, and, consequently, a sample container  8  located therein to a rotating, pivoting movement. 
   The cardanic suspension may take place via a cambered ring  12  which is mounted on the stand  1  via two axes  13  arranged opposite one another at 180° and on which the container holder  5  is mounted via two further axes  13  offset at 90° thereto. 
   For the evaporation and, if appropriate, derivatization of sample material in the sample container  8 , it is expedient to surround the container holder  5  with a heating device, for example, in the form of a heating coil  14 . 
   Located in the sample discharge position is a holder  15  with a discharge funnel  16 , to the lower end of which a discharge line can be connected. If appropriate, the discharge funnel  16  may be provided on the inlet side with a septum. 
   The sample discharger  2  comprises a sleeve-shaped holder  17  for a receptacle  18 . The receptacle  18  is connected on the top side to a plate  19 , whilst, on a bottom plate  20  of the sample discharger  2 , a plurality of cylinders  21  are arranged, which receive springs  22  which are supported on the bottom side and on the top side are supported on the plate  19  or guide inserts  23  carried by the latter and correspondingly prestress the receptacle  18  in the direction away from the bottom plate  20 . The holder  17  comprises on the inside a peripheral groove  24 , whilst the receptacle  18  receives captively balls  25  which can be pressed into the groove  24  in order to detain the receptacle  18  in the holder  17 . Furthermore, the receptacle  18  comprises an inner space  27  narrowing as far as a bottom-side passage orifice  26  and carries a syringe needle  28  which projects on the bottom side and which is connected to a connection part  30  projecting outwards through a vertical slot  29  of the holder  17 . The upper end of the slot  29  in this case serves at the same time as a stop for the non-detained receptacle  18  pressed upwards by the springs  22 . 
   The receptacle  18  serves for receiving a cartridge  31  in the form of a syringe body and consisting, for example, of glass or plastic, which inside it receives a packing  32  of adsorbing and/or sorbing material and on its extension  33  receives an attachment  34  with a syringe needle  35 . At the end lying opposite the syringe needle  35 , the cartridge  31  is closed by means of an insert  37  which abuts sealingly against the inner wall of the cartridge and has a central orifice covered by a sealing  36  and which carries a transporting head  38  extending outwards. The sealing  36  may be a membrane or a cartridge septum. 
   The cartridge  31  can be inserted into the receptacle  18 , the attachment  34  pressing outwards the balls  25  which, with the receptacle  18  pressed correspondingly far into the holder  17 , latch into the groove  24 . By the cartridge  31  being pulled up via the transporting head  38 , the balls  25  can be pressed out of the groove  24  again by the springs  22  and the receptacle  18  pressed upwards until the connection part  30  comes to an abutment in the slot  29 . 
   A freely programmable automatic handling device  39 , which may comprise a gripper  40  which is movable in three axes perpendicular to one another and by means of which the cartridge  31  provided with a transporting head  38  can be handled, is described in DE 102 19 790 C1. Sample containers  8  with a magnetizable cap  7  can thereby also be handled if the gripper  40  of the handling device  39  is designed for holding the sample container  8  or is provided for this purpose, for example, with inserted permanent magnets which can hold the sample container  8  via its magnetizable cap  7 . If appropriate, a further gripper, exchangeable for the gripper  40 , for example by rotation, or a second handling device may also be used for the sample container  8 . 
   The procedure is then as follows: 
   First, cartridges  31  are prepared thus far as disposable material and are stored in a magazine. This is performed expediently such that their syringe needles  35  are pierced through sealings, particularly septa, located in the magazine, so that the cartridges  31  are received, in a sealed manner. If appropriate, the dead space above the packing  32  of the cartridges  31  is reduced. 
   By means of the handling device  39 , a cartridge  31  removed from the magazine is inserted into the receptacle  18  of the sample discharger  2  which is in the sample discharge position, with the receptacle  18  being detained. 
   Thereafter, expediently, a conditioning of the cartridge  31  or of the packing  32  is performed first by injecting solvent through the sealing  36  into the cartridge  31  and emptying it through the syringe needle  35  into the discharge funnel  16  by means of an injector  41  which is an injection syringe or an injection needle connected to a pump, for example a hose pump or the like. If appropriate, this may be continued with further solvents which are taken, for example, through the injector  41  out of a respective bottle battery. 
   Subsequently, the sample discharge is performed by taking out sample material from a respective container, for example a vial, or a throughflow cell by means of the same or a further injector  41  and injecting it into the cartridge  31  through the sealing  36 . In order to allow a respective quantity of sample material flowing through the packing  32  even when an injection syringe is used as the injector  41 , this may even be carried out several times. Analytes adsorbed and/or sorbed by the packing  32  remain on the latter, whilst the rest passes through the injection needle  35  into the discharge funnel  16 . 
   The packing  32  may, if appropriate, be dried before and/or after the sample discharge, by, if appropriate, leading through heated inert gas. This may be performed via the injection needle of the injector  41 . For example, if an injection syringe is used as the injector  41 , this may have a lateral gas connection  42 , above which the piston  41   a  of the injection syringe must be drawn back for the ingress of gas. This may be carried out automatically, in a respectively programmed manner, by means of the handling device  39 . 
   A sample container  8  is arranged in the elution position by means of the handling device  39 . 
   When the sample discharge in the sample discharge position is terminated and the sample container  8  is in the elution position, the cartridge  31  is drawn up by means of the handling device  39  to an extent such that the receptacle  18  is released from its detention with the holder  17 , so that the syringe needles  28 ,  35  are drawn back and therefore the sample discharger  2  can be moved into the elution position. 
   After the sample discharger  2  has assumed its position above the sample container  8  in the elution position, the cartridge  31 , together with the packing  32  laden with analytes, is pressed into the receptacle  18  by means of the handling device  39 , and consequently the latter into its holder  17 , and detained. The syringe needles  28 ,  35  thereby penetrate the septum  6  of the sample container  8 . 
   By means of the injector  41 , eluent is injected through the sealing  36  into the cartridge  31 , if appropriate several times and if appropriate also in the form of different solvents, with the result that the eluent flows through the packing  32  and, laden with analytes, passes through the syringe needle  35  into the sample container  8 . The gas volume contained in the latter can escape through the second syringe needle  28  and the connection part  30 . 
   If appropriate, again, a drying operation may follow, in which, for example with the cartridge  31  drawn out, inert gas is introduced into the sample container  8  via the injection needle of the injector  41  and is discharged again via the syringe needle  28  pressed into the sample container  8  by means of the injector  41  via the receptacle  18 . In this case, for the purpose of assisting the evaporation of the solvent, the sample container  8  may be heated by means of the heating device  14 . During the drying operation, deaeration may be performed via the connection part  30 , if appropriate with the assistance of a vacuum. 
   It may then be necessary to treat the analytes which have remained in the sample container  8  once again with a solvent which is supplied via the injector  41 . For this purpose, the sample container  8  can be shaken by means of the electric motor  9  or the material in the sample container  8  can be agitated magnetically or by means of ultrasound. A derivatization step may also follow. 
   Subsequently, the sample container  8  can be arranged in a magazine, in order to take out sample material later for a, in particular, chromatographic analysis, or, by means of a removal syringe handled by the handling device  39 , sample material can be directly taken out through the septum  6  and supplied to an analyzer. 
   All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. 
   The invention now being fully described, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the appended claims.