WO2016156577A1

WO2016156577A1 - Device for transferring liquid samples

Info

Publication number: WO2016156577A1
Application number: PCT/EP2016/057231
Authority: WO
Inventors: Pierre ROBLIN; Javier Perez
Original assignee: Institut National De La Recherche Agronomique (Inra); Synchrotron Soleil
Priority date: 2015-04-03
Filing date: 2016-04-01
Publication date: 2016-10-06
Also published as: FR3034525B1; FR3034525A1

Abstract

The transfer device (10) comprises a sampling needle (24), means (26) of moving the needle (24) between the sample support (12) and the analysis device (14), a selector (28) comprising at least first (28A), second (28B) and third (28C) routes, of which the central route (28A) is connected to the sampling needle (24), the selector (28) being able selectively to connect two routes to one another, a sampling syringe (30), connected to the second route (28B) of the selector (28) and a conveying syringe (32), connected to the third route (28C) of the selector (28) and intended to contain an incompressible liquid.

Description

Device for transferring liquid samples

The present invention relates to a device for transferring liquid samples from a sample carrier to an analysis device.

The analysis device is for example a spectrophotometer, intended to measure the absorption, diffusion or fluorescence of liquid samples. For this purpose, the analysis device comprises a measuring cell for liquid sample, through which such a sample can transit.

Already known in the state of the art, transfer devices developed and optimized to perform high-speed measurements on such an analysis device. Such a transfer device is permanently assembled with the analysis device which is generally dedicated to only one type of experiment, so that it is difficult to transport from one analysis device to another. This transfer device can be particularly bulky, having significant dimensions related to the function for which it has been optimized, namely the rapid injection of samples into the measuring cell.

In addition, the known transfer devices are not suitable for injecting non-homogeneous samples, having unconventional physicochemical properties, especially very concentrated, viscous, semi-precipitated or semi-crystalline solutions, etc. Indeed, such a device is generally optimized for a standard type of sample homogeneous and low viscosity.

The object of the invention is in particular to remedy these drawbacks, by proposing a compact sample transfer device capable of conveying to any analysis device all types of liquid samples, in particular samples having physicochemical properties. unconventional.

For this purpose, the subject of the invention is in particular a device for transferring liquid samples from a sample carrier to an analysis device, the transfer device comprising a sampling needle, characterized in that it comprises:

means for moving the sampling needle between the sample holder and the analysis device,

a selector comprising at least first, second and third channels, the central channel of which is connected to the sampling needle, the selector being suitable for selectively connecting the central channel with one of the other channels,

a sampling syringe, connected to the second channel of the selector, - A routing syringe, connected to the third channel of the selector, intended to contain an incompressible liquid.

Such a transfer device is able to take all types of samples by means of the sampling needle, when this needle is connected to the sampling syringe, then to convey precisely this sample to the analysis device, when the needle is connected to the delivery syringe, pushing the sample with said incompressible liquid.

Advantageously, an air bubble is provided between the sample and the incompressible liquid, in order to avoid dilution of the sample.

It should be noted that the use of two separate syringes dissociates the sampling step, which is performed via the sampling syringe containing air, and the routing step, which uses the syringe for routing containing liquid.

Thus, by separating two circuits with two different pumps, it is avoided to contaminate the suction circuit with the transport liquid that could pollute the sample. On the other hand the use of two dedicated pumps simplifies the sequence of steps of the suction / routing process and also to generate the air bubble that separates the sample from the liquid transport.

A transfer device according to the invention may further comprise one or more of the following characteristics, taken alone or in any technically feasible combination.

- The selector comprises a fourth channel, connected to a source of incompressible liquid, including water.

- The selector has a fifth channel, connected to a source of compressed air.

The transfer device comprises a programmable microcontroller capable of controlling the displacement means, the selector, the sampling syringe and the routing syringe according to a predefined sequence.

- The transfer device comprises remote control means, allowing an operator to remotely control the moving means, the selector, the sampling syringe and the routing syringe.

- The selector is formed by a multi-channel valve.

The invention also relates to a method for transferring liquid samples from a sample holder comprising at least one sample receptacle, to an analysis device, by means of a transfer device as defined above, characterized in that what it includes: a step of positioning the sampling needle in a sample receptacle of the sample holder,

a step of connection, by the selector, of the central channel, connected to the sampling needle, with the second channel, connected to the sampling syringe, a step of taking the sample from the sampling needle by activating the sampling syringe, leaving an air bubble upstream of the sample,

a step of moving the picking needle out of the receptacle,

a step of moving the sampling needle to an injection element of the analysis device,

a step of injecting the sample contained in the sampling needle into the injection element, by activation of the sampling syringe,

a step of connecting the central channel, connected to the sampling needle, with the third channel, connected to the routing syringe, and

a step of conveying the sample to a measurement cell of the analysis device, by activating the conveying syringe so as to inject an incompressible liquid following the air bubble.

Advantageously, the method according to the invention may further comprise one or more of the following characteristics, taken alone or in any technically feasible combination.

The transfer method comprises a subsequent step of filling the syringe with incompressible liquid.

- The transfer process comprises a rinsing step, during which the central channel, connected to the sampling needle, is connected to the fourth channel, connected to the liquid source, the liquid thus flowing in the needle of then taken in the analysis device.

- The transfer process comprises a drying step, during which the central channel, connected to the sampling needle, is connected to the fifth channel, connected to the source of compressed air, the air thus flowing in the sampling needle then in the analysis device.

The transfer method comprises a step of moving the sample in the sampling needle, by activating the sampling syringe, to introduce air following the sample, so that the volume of the sample air bubble reaches a predetermined value, for example 10μ \ -. The invention will be better understood on reading the description which follows, given solely by way of example and with reference to the single appended figure, schematically showing a transfer device according to an exemplary embodiment of the invention. invention.

There is shown in the figure a device 10 for transferring liquid samples, from a sample support 12 to an analysis device 14.

Said sample holder 12 comprises a body 15 in which are formed receptacles 16, in which are arranged samples to be analyzed. These receptacles 16 are for example formed by housings in which are inserted vials, in particular glass, including the samples. The receptacles 16 are for example arranged in rows, each row extending in a longitudinal direction X, and the rows being aligned in a transverse direction Y perpendicular to the longitudinal direction X.

Advantageously, the sample support 12 comprises temperature control means. For this purpose, the body 15 of the sample holder 12 comprises means for circulating a coolant, in particular a refrigerant fluid, arranged to perform a heat exchange with the receptacles 16. These regulating means make it possible to maintain a sample contained in the sample holder 12 at a predefined temperature. This is especially necessary when the sample needs to be kept at this preset temperature.

The analysis device 14 is for example a spectrometer, comprising a measuring cell 18, through which is intended to circulate at least one sample.

The analysis device 14 further comprises means for spectrometric analysis of the sample passing through the measurement cell 18.

Such a device is for example intended to measure absorption, diffusion or fluorescence, etc. of the sample. For this purpose, the spectrometric analysis means are capable of passing a beam through the measuring cell 18, for example a beam of X-ray, visible light, ultraviolet or infrared.

An injection element 20 is arranged upstream of the measuring cell 18. This injection element 20 comprises an injection opening through which the samples are intended to be injected, and it is connected to the measuring cell 18 of the analysis device 14 by at least one pipe 21.

Advantageously, the analysis device 14 also comprises temperature control means. Thus, the temperature of a sample is regulated during its analysis. This is especially necessary when the sample needs to be analyzed at a preset temperature. Advantageously, a collection device 22 is arranged downstream of the analysis device 14, in order to collect the samples that have passed through the measurement cell 18. The collection device 22 is connected to the measurement cell 18 by at least one line 23. .

The collection device 22 comprises, for example, a dispensing needle, means for moving this dispensing needle from an outlet of the analysis device 14 for conveying a sample collected by the dispensing needle to a dispensing needle. sample holder, which may be the sample holder 12 described above, or another sample holder.

The transfer device 10 comprises a sampling needle 24.

The transfer device 10 further comprises means 26 for moving the sampling needle 24 between the sample holder 12 and the analysis device 14.

The displacement means 26 are particularly suitable for moving the sampling needle 24 along the longitudinal axis X and / or the transverse axis Y to move it from one of the receptacles 16, from which a sample has been taken, up to the injection element 20, in which the sample will be injected.

Advantageously, the displacement means 26 are also adapted to move the sampling needle 24 along a vertical axis Z perpendicular to the longitudinal X and transverse Y axes, to allow the insertion and withdrawal of the sampling needle. 24 in a receptacle 16 and in the opening of the injection element 20.

In the example described, the sample support 12 also comprises displacement means along the transverse direction Y, perpendicular to the longitudinal direction X and to the vertical direction Z. The displacement of the sample support 12 in the direction transverse Y makes it possible to bring a row of receptacles 16 desired within reach of the sampling needle 24. The sampling needle 24 can then move in the longitudinal direction X next to a desired receptacle 16 of said row, then is inserted into this receptacle 16 being moved in the vertical direction Z.

The transfer device 10 further comprises a selector 28, comprising at least one central channel 28A, a second channel 28B and a third channel 28C, and adapted to selectively connect the common channel 28A with one of the other channels. The selector 28 according to the invention further comprises a fourth channel 28D and a fifth channel 28E, and could include other additional channels if necessary.

The selector 28 is for example formed by a multi-channel valve.

Said sampling needle 24 is connected to the central channel 28A of the selector

28. Furthermore, the transfer device 10 comprises a sampling syringe 30, connected to the second channel 28B of the selector 28. This sampling syringe 30 comprises a body 30A and a piston 30B housed in the body 30A and defining therewith a sampling chamber. The sample chamber is filled with air, and the piston 30B is movable in the body 30A to vary the volume of the sample chamber, thereby generating a vacuum or an overpressure.

Thus, when the central lane 28A is connected to the second lane 28B, the sampling syringe 30 makes it possible to take a sample from the sampling needle 24, generating a depression.

The transfer device 10 also comprises a routing syringe

32, connected to the third channel 28C of the selector 28. This routing syringe 32 comprises a body 32A and a piston 32B housed in the body 32A and defining therewith a conveying chamber. The delivery chamber is intended to be filled with an incompressible liquid, for example water. The piston 32B is movable in the body 32A to vary the volume of the conveying chamber, thereby generating an overpressure.

Thus, when the central channel 28A is connected to the third channel 28C, the routing syringe makes it possible to push a sample by generating an overpressure, the sample thus being pushed by the incompressible liquid.

The sampling syringes 30 and routing 32 are provided with an L valve which allows their purge or their supply air or water respectively.

A source of rinsing liquid 34, especially water, is connected to the fourth channel 28D. This liquid source 34 makes it possible to rinse the analysis device 14 when the sampling needle 24 is connected to the injection element 20 and the central channel 28A is connected to the fourth channel 28D.

In addition, a source of compressed air 36 is connected to the fifth channel 28E. This source of compressed air 36 makes it possible to dry the analysis device 14 when the sampling needle 24 is connected to the injection element 20, and the central channel 28A is connected to the fifth channel 28E.

Advantageously, the transfer device 10 comprises a programmable microcontroller capable of controlling the displacement means 26, the selector 28, the sampling syringe 30, the routing syringe 32, and the sources of liquid 34 and compressed air 36 in a predetermined sequence. The transfer device 10 can thus be controlled remotely by an operator who can sequentially control the displacement means 26, the selector 28, the picking and delivery syringes 32, and the liquid sources 34 and compressed air 36. A method of transferring liquid samples from the sample holder 12 to the analyzer 14 will be described below by means of the transfer device 10 described above.

The transfer method first comprises a step of positioning the sampling needle 24 in a sample receptacle 16 of the sample holder 12. For this purpose, as described above, the sample holder 12 is, if necessary, moved in the transverse direction Y to bring a row of desired sample within range of the picking needle 24, then the picking needle 24 is moved in the longitudinal direction X to bring it opposite the receptacle 16 sample to be taken. The sampling needle 24 is finally moved in the vertical direction Z to be immersed in the receptacle 16.

The method then comprises a step of connecting, in the selector 28, the central channel 28A, connected to the needle 24, with the second channel 28B, connected to the sampling syringe 30.

The method then comprises a sample collection step, initially contained in the corresponding sample receptacle 16, in the sampling needle 24, by activation of the sampling syringe 30, the piston 30B of which moves to generate a depression thus sucking the sample into the sampling needle 24.

It should be noted that the sample is sucked only on a part of the sampling needle 24, so it is not sucked up to the selector, in order to leave an air bubble which will be used to separate the sample from the liquid incompressible during the routing in the analysis device 14. For example, the sampling needle has a volume, up to the selector, 60 μ. In this case, only 50 μl of sample is taken to leave 10 μl of air upstream of the sample.

The sampling needle 24 is withdrawn from the sample receptacle 16 by a displacement along the vertical axis Z, then the activation of the sampling syringe 30, the piston 30B moves to generate a depression in order to move the sample in the sampling needle 24.

Optionally, there is also provided a step of moving the sample in the sampling needle 24, by activation of the sampling syringe 30 with the sampling needle 24 disposed in the open air, so that the volume of the air bubble, which will be used to separate the sample incompressible liquid during the routing in the analysis device 14, substantially equal to a predefined value. Generally, the predefined value is ~ \ 0μ \ -, this value being optimized to offer a good compromise between a good separation to avoid contamination by the incompressible liquid, and a sufficiently small volume to avoid the phenomena of compression / decompression of the air bubble.

Thus, for example, in the case where the sampling needle has a volume, up to the selector, of 60 μΙ_, when the volume of the sample is less than 50 μΙ_, for example equal to 30 μΙ_, the displacement step allows 20 μΙ of additional air to be drawn downstream of the sample in order to leave 10 μΙ of air upstream of the sample.

It will be noted that these positioning and sampling steps can be repeated as necessary, in particular for taking more than one sample simultaneously in the same needle 24, in the case where it is desired to analyze a mixture or a dilution of several samples.

Once the sample, or the mixture of samples, to be analyzed is taken from the needle 24, the method comprises a step of moving the sampling needle 24 to the injection element 20 of the device During this step of displacement, the sampling needle 24, previously extracted from the receptacle 16 by a displacement along the vertical axis Z as indicated above, is displaced along the longitudinal axis X and / or transverse. Y until it is opposite the injection inlet of the injection element 20, then is moved in the vertical direction Z until it is inserted into this injection inlet.

The method then comprises a step of connecting the central channel 28A, connected to the needle 24, with the third channel 28C, connected to the routing syringe 32. At this stage, the delivery chamber is previously filled with liquid incompressible, especially water.

The method then comprises a step of conveying the sample to the measuring cell 18, by activating the routing syringe 32 so as to inject the incompressible liquid as a result of the air bubble, and thus carry out the thrust of the sample through this incompressible liquid. Thus, a simple, efficient and precise routing of the sample is carried out, whatever its properties, in particular for a non-homogeneous and viscous sample.

In the figure, there is shown in the measuring cell 18, the sample designated by the reference 38, air flanking the sample, designated by the reference 40, and the incompressible liquid pushing the sample, designated by reference 42.

With the air bubble 40, the sample 38 is not in contact with the liquid 42, and is therefore not diluted therein.

During its passage in the measuring cell 18, the sample 38 is analyzed in a conventional manner by the spectrometric analysis means. Once the sample has been analyzed, it is conveyed, always by means of the routing syringe 32, to an output of the analysis device, to which it is collected by the collection device 22.

Following this sample transfer, the transfer device 10 is reset. For this purpose, the piston 30B of the sampling syringe 30 is positioned in an initial position, in which the sampling chamber is emptied. In addition, a step is performed for filling the delivery syringe 32 with incompressible liquid.

Advantageously, the transfer method also comprises a step of rinsing the analysis device 14. During this step, the central channel 28A, connected to the sampling needle 24, is connected to the fourth channel 28D, connected to the liquid source, in order to circulate liquid in the sampling needle 24 and in the analysis device 14.

This rinsing step is followed by a drying step, during which the central lane 28A connected to the sampling needle 24 is connected to the fifth lane 28E, connected to the source of compressed air, in order to circulate the compressed air in the sampling needle 24 and in the analysis device 14 to perform the drying thereof. Thus, at the end of this drying step, the analysis device 14 comprises only air, and its walls are dry, eliminating the risk of dilution, with residual liquid, of a sample subsequently analyzed.

Note that the invention is not limited to the embodiment described, but could have various variants.

Claims

1. Device (10) for transferring liquid samples from a sample holder (12) to an analyzing device (14), the transfer device (10) having a sampling needle (24), characterized in that it comprises :

means (26) for moving the sampling needle (24) between the sample holder (12) and the analysis device (14),

a selector (28) comprising at least first (28A), second (28B) and third (28C) channels, whose central channel (28A) is connected to the sampling needle (24), the selector (28) being adapted to selectively connect the central channel (28A) with one of the other channels (28B, 28C, 28D, 28E),

- a sampling syringe (30), connected to the second channel (28B) of the selector (28),

- A routing syringe (32), connected to the third channel (28C) of the selector (28) for containing an incompressible liquid.

2. Transfer device (10) according to claim 1, wherein the selector (28) comprises a fourth channel (28D), connected to a source of incompressible liquid (34), including water.

The transfer device (10) according to claim 1 or 2, wherein the selector (28) has a fifth channel (28E) connected to a source of compressed air (36).

4. Transfer device (10) according to any one of the preceding claims, comprising a programmable microcontroller, adapted to control the displacement means (26), the selector (28), the sampling syringe (30) and the syringe d routing (32) according to a predefined sequence.

5. Transfer device (10) according to any one of the preceding claims, comprising remote control means, allowing an operator to remotely control the displacement means (26), the selector (28), the syringe of sampling (30) and the conveying syringe (32).

The transfer device (10) according to any one of the preceding claims, wherein the selector (28) is formed by a multi-channel valve.

A method of transferring liquid samples from a sample holder (12) having at least one sample receptacle (16) to an analyzer (14) by means of a transfer device (10). ) according to any one of the preceding claims, characterized in that it comprises:

a step of positioning the sampling needle (24) in a sample receptacle (16) of the sample holder (12),

a step of connection, by the selector (28), of the central channel (28A), connected to the sampling needle (24), with the second channel (28B), connected to the sampling syringe (32),

a step of taking the sample from the sampling needle (24), by activating the sampling syringe (30), leaving an air bubble (40) upstream of the sample (38),

a step of moving the sampling needle (24) out of the receptacle (16),

a step of moving the sampling needle (24) to an injection element (20) of the analysis device (14),

a step of injecting the sample (38) contained in the sampling needle (24) into the injection element (20), by activating the sampling syringe (30),

a step of connecting the central channel (28A), connected to the sampling needle (24), with the third channel (28C), connected to the routing syringe

(32), and

a step of conveying the sample (38) to a measurement cell (18) of the analysis device (14), by activating the conveying syringe (32) so as to inject an incompressible liquid (42) as a result of the air bubble (40).

8. Transfer method according to claim 7, by means of a transfer device (10) according to claim 2, comprising a subsequent step filling the conveying syringe (32) with incompressible liquid.

The transfer method according to claim 7 or 8, by means of a transfer device (10) according to claim 2, comprising a rinsing step, during which the central channel (28A), connected to the needle. sample (24), is connected to the fourth channel (28D), connected to the liquid source (34), the liquid thus flowing in the sampling needle (24) and in the analysis device (14).

Transfer method according to one of claims 7 to 9, by means of a transfer device (10) according to claim 3, comprising a drying step, during which the central channel (28A), connected at the sampling needle (24), is connected to the fifth channel (28E), connected to the source of compressed air (36), the air thus flowing in the sampling needle (24) and then in the device analysis (14).

1 1. Transfer method according to any one of claims 7 to 10, comprising a step of moving the sample in the sampling needle (24), by activation of the sampling syringe (30), to introduce air following the sample (38), so that the volume of the air bubble (40) reaches a predetermined value, for example 10μΙ_.