DE2331291A1 - Cryoscope for osmosis measurement - measures the lowering of the freezing point of small volumes of liquids - Google Patents

Cryoscope for osmosis measurement - measures the lowering of the freezing point of small volumes of liquids

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Publication number
DE2331291A1
DE2331291A1 DE19732331291 DE2331291A DE2331291A1 DE 2331291 A1 DE2331291 A1 DE 2331291A1 DE 19732331291 DE19732331291 DE 19732331291 DE 2331291 A DE2331291 A DE 2331291A DE 2331291 A1 DE2331291 A1 DE 2331291A1
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DE
Germany
Prior art keywords
liquid
cryoscope
freezing point
liquids
small volumes
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.)
Pending
Application number
DE19732331291
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German (de)
Inventor
Hans-J Dr Altmann
Herbert Dr Knauer
Klaus Noack
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.)
KG Dr-Ing Herbert Knauer & Co 1000 Berlin GmbH
Original Assignee
KG Dr-Ing Herbert Knauer & Co 1000 Berlin GmbH
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.)
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Publication date
Application filed by KG Dr-Ing Herbert Knauer & Co 1000 Berlin GmbH filed Critical KG Dr-Ing Herbert Knauer & Co 1000 Berlin GmbH
Priority to DE19732331291 priority Critical patent/DE2331291A1/en
Publication of DE2331291A1 publication Critical patent/DE2331291A1/en
Pending legal-status Critical Current

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Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N25/00—Investigating or analyzing materials by the use of thermal means
    • G01N25/02—Investigating or analyzing materials by the use of thermal means by investigating changes of state or changes of phase; by investigating sintering
    • G01N25/04—Investigating or analyzing materials by the use of thermal means by investigating changes of state or changes of phase; by investigating sintering of melting point; of freezing point; of softening point

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  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Sampling And Sample Adjustment (AREA)

Abstract

The shape of the liquid sample is determined by metal sheets, wires or strips, so that the liquid is symmetrically distributed around a temp sensor. The crystallisation process is initiated in an undercooled liquid by introduction into the liquid of a stronger undercooled element of low mass and thermal conduction, with crystallisation seeds on its surface. The devices are placed in a cooling chamber whose wall temp is kept at -10 to -40 deg.C. The device are protected by a protective jacket placed over them. This arrangement, together with a sensitive electronic temp. display, forms a cryoscope for osmosis or concentration of small sample measurement.

Description

20. Mai 1973May 20, 1973

Kryoskop (Gefrierpunktsosmometer) Cryoscope (freezing point osmometer)

Die Messung der Gefrierpunktserniedrigung von Lösungen erlaubt eine Bestimmung der Konzentration der gelösten Substanzen in der Lösung, bzw. der in der Lösung enthaltenen Anzahl gelöster Teilchen. Diese Meßmethode wird als Kryoskopie bezeichnet. Zur Messung wird die flüssige Probe unterkühlt, die Kristallisation des Lösungsmittels ausgelöst und die resultierende Gefrierpunktserniedrigung Δ T gemessen. Für eine gute Reproduzierbarkeit der Messungen ist das momentane Auslösen der Kristallisation bei einer bestimmten Unterkühlungstemperatur notwendig.The measurement of the depression of the freezing point of solutions allows a determination of the concentration of the dissolved substances in the solution, or the number of dissolved substances contained in the solution Particle. This measurement method is called cryoscopy. For the measurement, the liquid sample is supercooled, the crystallization of the solvent triggered and the resulting depression of the freezing point Δ T measured. The momentary triggering of the crystallization is essential for good reproducibility of the measurements necessary at a certain subcooling temperature.

Wir hängen die zu messende Probe als Tropfen an die Spitze eines temperaturempfindlichen Fühlers in einen geeigneten Haltebügel, der das Abfallen des Tropfens verhindert. Zugleich formt der Haltebügel (Ring, Schlaufe, Klammer) den Tropfen so, daß die jeweilige Oberflächenspannung nicht in die Tropfenform eingeht. .We hang the sample to be measured as a drop on the tip of a temperature-sensitive probe in a suitable one Retaining bracket that prevents the drop from falling off. At the same time, the bracket (ring, loop, clip) shapes the drop so that that the respective surface tension does not enter into the drop shape. .

Dadurch wird eine gleichförmige Verteilung der flüssigen Probe um den Temperaturfühler und als Folge daraus ein symetrisches Temperaturprofil um den Temperaturfühler nach Auslösung der Kristallisation erreicht.This results in a uniform distribution of the liquid sample around the temperature sensor and, as a result, a symmetrical one Temperature profile around the temperature sensor after triggering the Crystallization achieved.

Die derart an einem Temperaturfühler befestigte flüssige Probe wird in dem Luftraum oberhalb einer Kühlfläche überwiegend durch Abstrahlung von Wärme auf die notwendige Temperatur unterkühlt. Ein Merkmal dieser Kühlfläche ist ihre ungewöhnlich tiefe Temperatur von -10 bis -400C. Ist diese erreicht, wird die Spitze eines Drahtes, der sich unterhalb des Tropfens auf oder nahe an der Kühlfläche befindet in den Tropfen gehoben. Die Lage und geringe Masse dieses Auslösedrahtes nahe der Kühlfläche während der Unterkühlungsphase gewährleistet, daß dieser Draht nahezu die Temperatur der Kühlfläche angenommen hat. Er berührt den unterkühlten Tropfen mit einer tieferen Temperatur und löst momentan diese Kristallisation aus.The liquid sample attached to a temperature sensor in this way is subcooled to the required temperature in the air space above a cooling surface, predominantly by radiation of heat. A feature of this cooling surface is its unusually low temperature from -10 to -40 0 C. If achieved this, the tip of a wire, which is located below the droplet on or near the cooling surface is lifted into the drop. The position and low mass of this trigger wire close to the cooling surface during the subcooling phase ensures that this wire has almost assumed the temperature of the cooling surface. It touches the supercooled drop at a lower temperature and momentarily triggers this crystallization.

409882/0635 -2-409882/0635 - 2 -

Claims (1)

Blatt 3Sheet 3 PatentansprücheClaims Vorrichtung zur Messung der Gefrierpunktserniedrigung geringer Volumina Flüssigkeiten zur Bestimmung der Osmolarität, dadurch gekennzeichnet, daß die geometrische Form der flüssigen Probe durch Formbleche, -drähte, -Stege vorgebildet und eine symetrische Verteilung der flüssigen Phase um einen Temperaturfühler ermöglicht wird.Device for measuring the depression of the freezing point small volumes of liquids for determining osmolarity, characterized in that the geometric The shape of the liquid sample is pre-formed by shaped sheets, wires and webs and a symmetrical distribution of the liquid Phase around a temperature sensor is enabled. Vorrichtung zum Auslösen der Kristallisation einer unterkühlten Flüssigkeit, dadurch gekennzeichnet, daß ein stärker unterkühlter Körper geringer Masse und Wärmeleitfähigkeit, dessen Oberfläche mit Kristallisationskeimen besetzt sein kann, in die Flüssigkeit gebracht wird.Device for triggering the crystallization of a supercooled liquid, characterized in that a more supercooled body of low mass and thermal conductivity, its surface with crystal nuclei may be occupied, is brought into the liquid. Vorrichtung zur kontinuierlichen Unterkühlung, dadurch gekennzeichnet, daß der Luftraum einer trogförmigen Kühlkammer, deren Wandtemperatur -10 bis -4O0C beträgt, die unter Anspruch 1 und 2 beschriebenen Vorrichtungen aufnimmt.Device for continuous supercooling, characterized in that the air space of a trough-shaped cooling chamber, the wall temperature of which is -10 to -4O 0 C, accommodates the devices described in claims 1 and 2. Vorrichtung zum Schutz der in Anspruch 1 und 2 beschriebenen Vorrichtungen, dadurch gekennzeichnet, daß ein Schutzmantel über diese geschoben wird.Device for protecting the devices described in claims 1 and 2, characterized in that a Protective sheath is pushed over this. Vorrichtung nach Anspruch 1 und folgende, dadurch gekennzeichnet, daß durch deren Zusammenwirken und in Verbindung mit einer empfindlichen elektronischen Temperaturanzeige ein Kryoskop zur Messung der Osmolarität oder der Konzentration geringer Probemengen erhalten wird.Device according to claim 1 and following, characterized in that that through their interaction and in connection with a sensitive electronic temperature display a cryoscope for measuring osmolarity or the concentration of small amounts of sample is obtained. 409882/0635409882/0635
DE19732331291 1973-06-15 1973-06-15 Cryoscope for osmosis measurement - measures the lowering of the freezing point of small volumes of liquids Pending DE2331291A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE19732331291 DE2331291A1 (en) 1973-06-15 1973-06-15 Cryoscope for osmosis measurement - measures the lowering of the freezing point of small volumes of liquids

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19732331291 DE2331291A1 (en) 1973-06-15 1973-06-15 Cryoscope for osmosis measurement - measures the lowering of the freezing point of small volumes of liquids

Publications (1)

Publication Number Publication Date
DE2331291A1 true DE2331291A1 (en) 1975-01-09

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DE19732331291 Pending DE2331291A1 (en) 1973-06-15 1973-06-15 Cryoscope for osmosis measurement - measures the lowering of the freezing point of small volumes of liquids

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DE (1) DE2331291A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2951709A1 (en) * 1979-12-19 1981-07-02 Harald Dipl.-Ing. 1000 Berlin Göritz Freezing point osmometer device - has separate cooling units for solution and for wire used to initiate crystallisation
EP3922974A1 (en) 2020-06-09 2021-12-15 Markus Meske Device and method for freezing a sample and freezing point osmometer and method for the osmometric determination of a sample

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2951709A1 (en) * 1979-12-19 1981-07-02 Harald Dipl.-Ing. 1000 Berlin Göritz Freezing point osmometer device - has separate cooling units for solution and for wire used to initiate crystallisation
EP3922974A1 (en) 2020-06-09 2021-12-15 Markus Meske Device and method for freezing a sample and freezing point osmometer and method for the osmometric determination of a sample

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