EP0490592A1 - Moyens d'agitation - Google Patents

Moyens d'agitation Download PDF

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Publication number
EP0490592A1
EP0490592A1 EP91311371A EP91311371A EP0490592A1 EP 0490592 A1 EP0490592 A1 EP 0490592A1 EP 91311371 A EP91311371 A EP 91311371A EP 91311371 A EP91311371 A EP 91311371A EP 0490592 A1 EP0490592 A1 EP 0490592A1
Authority
EP
European Patent Office
Prior art keywords
probe
vessel
sample
liquid
operable
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP91311371A
Other languages
German (de)
English (en)
Inventor
Michael Ron Hammer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Varian Australia Pty Ltd
Original Assignee
Varian Australia Pty Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Varian Australia Pty Ltd filed Critical Varian Australia Pty Ltd
Publication of EP0490592A1 publication Critical patent/EP0490592A1/fr
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F31/00—Mixers with shaking, oscillating, or vibrating mechanisms
    • B01F31/44—Mixers with shaking, oscillating, or vibrating mechanisms with stirrers performing an oscillatory, vibratory or shaking movement
    • B01F31/441—Mixers with shaking, oscillating, or vibrating mechanisms with stirrers performing an oscillatory, vibratory or shaking movement performing a rectilinear reciprocating movement
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F2101/00—Mixing characterised by the nature of the mixed materials or by the application field
    • B01F2101/23—Mixing of laboratory samples e.g. in preparation of analysing or testing properties of materials

Definitions

  • This invention relates to the handling of liquids, and in particular relates to a method and means for mixing liquids.
  • the invention is partiuclarly concerned with means whereby two or more liquids are stirred so as to mix together. It will be convenient to hereinafter describe the invention with reference to stirring means for use in automated chemical analysis apparatus such as a spectrometer.
  • One prior automated sample mixing device includes means for passing a gas stream through the body of constituents so as to promote mixing of those constituents.
  • the individual constituents are mixed by the gas bubbling through the body of liquid for a suitable period of time.
  • This approach it has been found, has three main drawbacks. The first is that the gas is a foreign component which can react with one or more of the constituents of the mixture and thus affect the result of the analysis. This problem can be minimised but not eliminated by using pure and inert gases.
  • the second problem is the additional costs and complexity of the gas plumbing required.
  • the third problem is the cost and inconvenience of a high purity inert gas supply.
  • a second approach to the problem has been to repeatedly draw up a mixture into the sampling probe or syringe and then redispense it back into the sample container one or more times.
  • the idea behind this approach is that turbulence caused by the fluid movement will result in stirring and consequent mixing.
  • the approach is not satisfactory because of the time taken to repeatedly draw up and re-eject the liquid, and also becaue of the inadequate degree of uniformity which is achievable.
  • a third approach is to use a separate stirrer element which is caused to move by a rotating magnetic field.
  • This approach may be up to 500 such containers in any one automatic sample preparation device, and it would be expensive and cumbersome to provide a separate stirrer bar and associated rotating magnetic field for each such container.
  • the alternative of moving a single stirrer from one container to another container is not acceptable because of the inherent problem of cross-contamination of liquid from different containers.
  • a further object of the invention is to provide relatively inexpensive and uncomplicated stirring means which is adapted for use in an automated sampling system.
  • a still further object of the invention is to provide an improved method of handling samples for analysis by spectroscopic means.
  • liquid handling apparatus including a hollow probe through which liquid can be introduced into or withdrawn from a vessel, flow generating means connected to said probe and being operable to cause liquid to move through said probe, and drive means connected to said probe and being operable to cause movement of the probe relative to a vessel within which the probe is located so that the probe functions to stir the contents of that vessel.
  • the flow generating means may be of any suitable form. It may be a motor driven syringe, or any other type of pump, or it may be a device such a nebulizer which is operable to draw liquid out of the vessel through the probe.
  • Apparatus according to the invention is particularly suited for use as part of an automated sampler of the kind used in spectroscopy.
  • the apparatus has advantage in either of two use situations.
  • the sample to be handled by the apparatus is composed of two or more liquids which are mixed together.
  • the sample is composed of a body of liquid in which there is a dispersion of solid particulate material.
  • the flow generating means will usually be a pump of some form which may be operated to push one liquid constituent through the probe to enter into and mix with another liquid constituent, or which may be operated to withdraw the liquid sample from a vessel through the probe.
  • the movement of the probe which results from operation of the drive means causes the probe to function as a stirrer such that the sample is maintained as a homogeneous mixture of liquids.
  • the flow generating means may not be a pump as such.
  • it may be the nebulizer of a spectrometer to which the apparatus is connected, or it may be some other device which can influence the contents of the sample vessel so that the sample is withdrawn through the probe.
  • Pump means as referred to in relation to the first mentioned situation may be part of the total system, but operation of such pump means is not necessary for the sample to be withdrawn through the probe. Movement of the probe under the influence of the drive means again causes the probe to act as a stirrer, and it is desirable to stir the sample to ensure regular dispersion of the particulate material immediately before withdrawal of the sample through the probe.
  • the device which acts as a stirrer - namely, the probe - is also part of the standard conduit system whereby material is moved into or out of a sample vessel.
  • a method of mixing liquids including the steps of, inserting a hollow probe into a liquid body contained in a vessel, introducing a liquid additive into the liquid body through said probe, and causing said probe to move relative to the vessel such as to stir the contents of the vessel and thereby cause the liquid additive to mix with the liquid body.
  • a method of handling a sample composed of a body of liquid and solid particulate material dispersed throughout that body including the steps of introducing a hollow probe into a vessel containing said sample, causing said probe to move relative to the vessel and thereby stir the sample so that said particulate material is maintained in suspension in the liquid body, and removing said sample from the vessel through said probe.
  • any suitable means may be used to cause movement of the probe such that it functions as an effective stirrer.
  • the probe may be caused to vibrate or shake, or it may be caused to rotate or oscillate about its longitudinal axis or another axis which is laterally offset from the longitudinal axis.
  • bodily lateral shifting of the probe may be combined with rotary or oscillatory motion. If the probe is rotated, the direction of that rotation may be reversed periodically.
  • the probe may be also moved longitudinally in a reciprocating fashion to optimize its stirring influence throughout the depth of the liquid body and thereby avoid stratification of the sample. Such longitudinal movement may occur simultaneous with or in alternating fashion with the other movement of the probe.
  • Apparatus according to the invention is particularly suited for use as part of an automatic sampler for a spectrometer.
  • probe positioning means will be operable to move the probe into and out of registry with a plurality of sample vessels. It is preferred that the aforementioned drive means is connected to or forms part of that positioning means.
  • Figure 1 is a diagrammatic representation of the essential components of apparatus according to one embodiment of the invention.
  • Figure 2 is a semi-diagrammatic view showing the probe of Figure 1 connected to positioning and elevating means.
  • Figure 3 is a semi-diagrammatic view of sample analysis apparatus incorporating an embodiment of the invention.
  • Figure 1 shows one possible form of apparatus incorporating an embodiment of the invention, and which operates as part of an auto sampler for a spectrometer.
  • the spectrometer can be of any kind including UV, atomic absorption, and inductively coupled plasma spectrometers.
  • the apparatus of Figure 1 includes a probe 1 which is in the form of an open ended tube made of a suitable material. It is preferred that the probe 1 is relatively rigid so that stirring movement of the probe does not result in one part - e. g., the free end - undergoing significantly greater excursion than any other part of the probe. That is, whatever the excursion of the probe 1, it is preferably substantially regular throughout the length of the probe so that the stirring effect of the probe is substantially constant throughout that length. In some applications however, such regular excursion may not be necessary, and it is possible that greater excursion of the probe at the tip end can be used to advantage in some situations.
  • the probe 1 is connected to a pump 2 through conduit 3. It is preferred that a transitory storage facility for liquid is provided between the probe 1 and the pump 2.
  • that facility is in the form of a tubular coil 4 formed of a suitable material such as of polytetraflouroethelyne (PTFE).
  • PTFE polytetraflouroethelyne
  • the coil 4 is used to store any sample drawn into the conduit 3 from the sample vessel 5, and thereby avoid the sample coming into contact with the pump 2.
  • the pump 2 is formed by a syringe having a body of glass construction which could react with some samples.
  • the syringe pump 2 is driven by a motor 6 through a suitable drive connection 7, and is preferably operable in either of two modes. In one mode, the pump 2 is operated to produce negative pressure in the conduit 3 and the connected probe 1, and thereby causes sample to be withdrawn from the vessel 5 into the conduit 3. In the other mode of operation, the pump 2 is operated to produce positive pressure in the conduit 3 so as to cause the sample to be expelled through the outlet conduit 8.
  • the syringe pump 2 is connectable through a conduit 9 to a vessel 10 containing diluent, and that connection is controlled by a valve 11 which is preferably solenoid operated.
  • a valve 11 which is preferably solenoid operated.
  • the pump 2 In the position of the valve 11 as shown in Figure 1, the pump 2 is connected to the probe 1 and the outlet 8.
  • the valve 11 connects the pump 2 to the diluent vessel 10 and disconnects the pump 2 from the probe. Under those circumstances, the pump 2 can be operated to draw diluent into the syringe body for subsequent discharge into the sample vessel 5 when the valve 11 is moved back to the position shown in full line in Figure 1.
  • the outlet 8 is shown connectable to a spectrometer (not shown in Figure 1) through a valve 12, which may also he solenoid operated.
  • the spectrometer connection is diagrammatically represented by the line 13.
  • the valve 12 When the valve 12 is positioned as shown in Figure 1, the probe is isolated from the spectrometer and sample preparation can be carried out under that condition.
  • the valve 12 however, connects the diluent vessel 10 to the spectrometer through the conduit 14, and that is for a purpose well known in the art and which has no bearing on the present invention.
  • the probe 1 is connected to the spectrometer so that sample analysis can be carried out in a known manner.
  • Figure 2 shows one possible arrangement for positioning the probe 1 in registry with the sample vessel 5, and for moving the probe 1 into and out of that vessel.
  • the probe 1 is mounted on the outer end of an articulated arm assembly 15, and the outer end of that assembly 15 is mounted on a post 16 such that it is rotatable about a primary axis 17.
  • the post 16 is connected to elevating means 18 which is operable to raise and lower the arm assembly 15 as required.
  • the assembly 15 comprises an inner or primary positioning arm 19, and an outer or secondary positioning arm 20.
  • the two arms 19 and 20 are connected for relative movement about a secondary axis 21 which is substantially parallel to the primary axis 17.
  • the probe 1 is subjected to the influence of drive means 22 such that it can be caused to undergo stirring movement as previously defined.
  • drive means 22 includes a stepper motor or similar device which is connected to the arm 20 and is operable to cause that arm to oscillate about the axis 21.
  • the extent and speed of the oscillation can be determined according to individual requirements. Furthermore, the extent and/or speed of oscillation may be varied during a stirring operation.
  • the drive means 22 may be operated to cause the probe 1 to undergo stirring movement immediately prior to the pump 2 being operated to direct sample into an associated spectrometer.
  • Such longitudinal movement may serve to avoid stratification of the sample constituents and ensure that the consistency of the sample is regular throughout the depth of the vessel 5.
  • the degree of such longitudinal movement is preferably regulated so that the tip of the probe does not leave the sample during stirring movement of the probe.
  • the probe 1 may be lifted out of that vessel by appropriate operation of the elevating means 18.
  • the drive means 22 may be operated to cause the probe 1 to move and thereby promote separation of any droplets of sample which have remained resident on the outside of the probe 1. It may be desirable to effect any such droplet removal under conditions such that the droplets do not contaminate other samples, or sample constituents, in the vicinity of the probe 1.
  • FIG. 3 shows sample analysis apparatus incorporating the invention.
  • the main components of the apparatus shown are an auto-sampler 23, a spectrometer 24 and control means 25.
  • the control means is typically a computer which is connected to both the sampler 23 and the spectrometer 24 so as to control and coordinate the operation of both of those instruments.
  • the sampler 23 as shown includes a plurality of racks 26, each of which can hold a plurality of vessels (e. g., tubes) for containing samples and constituents intended to form a sample mixture.
  • vessels e. g., tubes
  • the arm assembly 15 is driven through a stepper motor (not shown) or other suitable drive mechanism such as to position the probe 1 in registry with a selected vessel in the racks 26.
  • the aforementioned drive mechanism will control the rotational position of the primary arm 19, whereas the drive motor 22 is operable to move the secondary arm 20 relative to the primary arm 19.
  • the drive motor 22 may therefore subject the arm 20 to different movement according to whether it is being operated for stirring or probe positioning purposes.
  • a particular advantage of the arrangement discribed is that the probe positioning means in effect adopts the further function of driving the probe through stirring movement. Consequently, modification of existing apparatus to function in the manner required by the invention, is a relatively simple procedure.
  • Operation of the elevating means 18 enables the probe 1 to be removed from or located in a selected vessel.
  • the probe 1 It is usually important that the probe 1 not contain any liquid prior to it being inserted into a vessel, since that liquid may be shaken out of the probe 1 as it is vibrated. The possibility of the liquid becoming discharged in this manner can be eliminated by filling the probe 1 with air prior to commencing a mixing operation. The difference in specific weights between the air in the probe 1 and the liquid in the associated vessel prevents the air being mixed with the sample solution.
  • the probe 1 may be filled with air by drawing up a volume of air equal to the internal volume of the probe whilst the end of the probe is open to the air.
  • the probe 1 since the probe 1 will in any event need to move from one sample vessel to another in order to pick up the samples from each vessel, there will be no additional source of contamination from one sample container to the next as has been the problem with other prior sample stirring devices. It is relevant that the mixing device is in fact the probe which must in any event be moved from one vessel to the next, because as a consequence there is no additional source of contamination beyond that which would otherwise be the case. Thus, the mixing process adds no further carry over problem. Generally the apparatus will be programmed so that the operator has the option of automatically washing the probe in a rinse solution between each sample container.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Sampling And Sample Adjustment (AREA)
EP91311371A 1990-12-07 1991-12-06 Moyens d'agitation Withdrawn EP0490592A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AU3753/90 1990-12-07
AU375390 1990-12-07

Publications (1)

Publication Number Publication Date
EP0490592A1 true EP0490592A1 (fr) 1992-06-17

Family

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Family Applications (1)

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EP91311371A Withdrawn EP0490592A1 (fr) 1990-12-07 1991-12-06 Moyens d'agitation

Country Status (1)

Country Link
EP (1) EP0490592A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1533024A1 (fr) * 2003-11-24 2005-05-25 F. Hoffmann-La Roche Ag Appareil de désintégration d'agglomérations de particules, en particulier pour la fragmentation de microparticules par mouvement d'un piston dans un récipient
EP1838423A2 (fr) * 2005-01-10 2007-10-03 Dade Behring Inc. Procede et dispositif pour melanger des echantillons liquides dans un contenant a l'aide d'un modele de brassage bidimensionnel
US8438939B1 (en) 2009-09-14 2013-05-14 Elemental Scientific, Inc. Sample introduction system with mixing

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3347531A (en) * 1966-03-22 1967-10-17 Ira J Strong Stirring apparatus for plural test tubes
DE2651903A1 (de) * 1976-11-13 1978-05-18 Thomae Gmbh Dr K Verfahren und vorrichtung zur vorbereitung analytischer probereihen und zur ueberfuehrung dieser reihen von einer linearen in eine radiale anordnung
FR2469953A1 (fr) * 1979-11-21 1981-05-29 Toulouse Inst Serotherapie Procede et dispositif d'agitation, d'homogeneisation et de prelevement dans des conditions steriles de liquides meme fortement charges
US4341736A (en) * 1980-01-28 1982-07-27 Coulter Electronics, Inc. Fluid transfer mechanism

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3347531A (en) * 1966-03-22 1967-10-17 Ira J Strong Stirring apparatus for plural test tubes
DE2651903A1 (de) * 1976-11-13 1978-05-18 Thomae Gmbh Dr K Verfahren und vorrichtung zur vorbereitung analytischer probereihen und zur ueberfuehrung dieser reihen von einer linearen in eine radiale anordnung
FR2469953A1 (fr) * 1979-11-21 1981-05-29 Toulouse Inst Serotherapie Procede et dispositif d'agitation, d'homogeneisation et de prelevement dans des conditions steriles de liquides meme fortement charges
US4341736A (en) * 1980-01-28 1982-07-27 Coulter Electronics, Inc. Fluid transfer mechanism

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1533024A1 (fr) * 2003-11-24 2005-05-25 F. Hoffmann-La Roche Ag Appareil de désintégration d'agglomérations de particules, en particulier pour la fragmentation de microparticules par mouvement d'un piston dans un récipient
EP1838423A2 (fr) * 2005-01-10 2007-10-03 Dade Behring Inc. Procede et dispositif pour melanger des echantillons liquides dans un contenant a l'aide d'un modele de brassage bidimensionnel
EP1838423A4 (fr) * 2005-01-10 2011-06-29 Siemens Healthcare Diagnostics Procede et dispositif pour melanger des echantillons liquides dans un contenant a l'aide d'un modele de brassage bidimensionnel
US8438939B1 (en) 2009-09-14 2013-05-14 Elemental Scientific, Inc. Sample introduction system with mixing
US8806966B1 (en) 2009-09-14 2014-08-19 Elemental Scientific, Inc. Sample introduction system with mixing
US9844761B1 (en) 2009-09-14 2017-12-19 Elemental Scientific, Inc. Sample introduction system with mixing
US10569241B1 (en) 2009-09-14 2020-02-25 Elemental Scientific, Inc. Sample introduction system with mixing
US11376557B1 (en) 2009-09-14 2022-07-05 Elemental Scientific, Inc. Sample introduction system with mixing

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