Science Together Freezing point osmometry Made in Germany K-7400S Semi-Micro Osmometer Freezing point osmometry The KNAUER freezing point osmometer The measurement principle of the K-7400S This effect depends only on the number of par-Semi-Micro Osmometer is based on the colligative ticles in the liquid and not on the physical or The K-7400S Semi-Micro Osmometer can determine the exact property of freezing point depression. chemical properties of the solutes. Due to this If a solute is added to a liquid this results in a linear correlation, the osmolality of a sample can freezing point of aqueous solutions. The osmolality of various decreased freezing point of the solution. The de-be determined by precisely measuring its freezing samples like pharmaceutical solutions or soft drinks can thus pression is 1.858 K per 1 mole of ideally solved point. compound in one liter of water. be easily determined. Schematic illustration of the measurement unit 1 2 3 Stirring wire Cooling block Thermistor Variable Fast Easy Sample & measurement of solutes & small sample volume (~ 2 min) user-friendly handling (50 — 150 µl) At the beginning of a measurement the sample is cooled by a microprocessor-controlled peltier element. During this process, the solution is super-cooled below 0 °C while still being liquid. At a certain temperature the freezing process is initiated by a rotation of the stirring wire. The formation of ice crystals causes the release of ther-Osmolality is a general measure of the particle mal energy, thus rising the temperature of the 10 concentration in a solute. Itś not depending on sample. After a short period of time an equilibri-C Cooling the nature of molecules but just their number. um is reached where melting and thawing of ice Therefore, a two molar solution of a non-dissoci-crystals are balanced and the sample’s tempera-ature ° ating molecule (A) has the same osmolality as a A B ture stays constant. This plateau marks the real erp Freezing point one molar solution of a fully dissociating salt com-freezing point of the sample. Tem 0 posed of two ions (B). The osmolality of a solution During the whole process the temperature of the Super-is the same, even when molecules vary in shape solution is measured by a high-precision ther-cooling (C) as well as in size (D). Therefore, all solutions C D mistor. Thanks to a resolution of 1/1 000 K the freez-containing the same number of osmotical y active ing point temperature is exactly determined and Freezing initiation particles — regardless of their chemical properties even small differences in osmolality of two sam- -10 — exhibit the same osmolality. ples can be measured. Time 2 www.knauer.net/osmometry 3 K-7400S Semi-Micro Osmometer Freezing point osmometry RS-232 interface Measuring head Connection for printer With the stirring wire and its or software control. high-precision thermistor the measuring head is a key component of the osmometer. Sample volume 50 — 150 µl Parking position Osmolality range 0 — 2 000 mOsmol/kg The four pedestals ensure safe storage of the mea- Resolution 1 mOsmol/kg suring head while the device is not in use. Test time ~ 2 min Precision SD ≤ 4 mOsmol/kg [0 — 400 mOsmol/kg], RSD ≤ 1 % [400 — 2 000 mOsmol/kg] Linearity ± 1.5 % [0 — 2 000 mOsmol/kg] Calibration Two-point calibration (0 mOsmol/kg and one free Control via keypad selectable osmolality), optional: Three-point calibration The instrument can be (0 Osmol/kg and two free selectable osmolalities) fully controlled via Interfaces RS-232 port the keypad. All settings for calibrations and Control Keypad (LC display, 2 rows with 24 characters) measurements can Optional: EuroOsmo 7400 software easily be changed and displayed. Power supply 100 — 240 V, 50 — 60 Hz, 70 W Dimensions 160 × 182 × 340 mm (W × H × D) Casing Weight 4.5 kg Small and robust design Ambient conditions 10 — 35 °C, 20 — 80 % relative humidity (noncondensing) that saves bench space. 4 www.knauer.net/osmometry 5 K-7400S Semi-Micro Osmometer Freezing point osmometry Sample & result list Monitor view Measurement view Individual naming of Overview of the last Visualization of the Additional data management with samples and overview measurements to current measurement. of test results. allow quality control a user-friendly interface of the analysis. The K-7400S Semi-Micro Osmometer is a stand-Samples can be named individually and the mea-alone device. Therefore, all functions of the in-surement results can be saved for archiving. struments are accessible via the keypad. For ad-The data can also be exported in different file ditional storage and data management functions formats (e.g. *.xls, ASCII or Tab delimited text files). users can work with the EuroOsmo 7400 software. Thus, also the import to laboratory information It offers a user-friendly interface to control the management systems (LIMS) is possible. K-7400S Semi-Micro Osmometer via PC. Mea-Supporting the use of a barcode scanner, sample surement parameters can easily be changed and identification can be transferred automatically sent to the instrument via the software. For each reducing the risk of wrong sample assignment. sample a temperature curve is displayed to visu-alize the measurement process. Change settings Visualization of the User-friendly more easily measurement interface Operating systems: PC hardware: • Windows XP The system requirements for installation of • Windows Vista the software are very low. In general, EuroOsmo • Windows 7 7400 is working on every PC that is suited for • Windows 8 one of the listed operating systems. One • Windows 10 RS-232 port is required for connection to the instrument. 6 www.knauer.net/osmometry 7 K-7400S Semi-Micro Osmometer Freezing point osmometry 1100 1000 900 800 700 600 isotonic range = 500 300 mOsmol/kg ± 10% 400 300 Osmolality (mOsmol/kg) 200 Freezing point osmometry is a fast and reliable method to 100 0 determine the osmolality of various solutions. beer Beer In combination with the small sample size required and the tdrink Isotonic tdrink 1 Isotonic tdrink 2 Isotonic tdrink 3 sof sof sof Isotonic drinks are becoming test method is needed. For this ola sof with alcohol simple measurement procedure it is a preferred method for Non-alcoholic C more and more popular among determination, the K-7400S laboratory analysis in industry and academia. professional and amateur ath-Semi-Micro Osmometer is per- Analysis of several isotonic and letes. Due to their special com-fectly suited because it works non-isotonic drinks. position, contained nutrients and independently of sample com-Six different samples of isotonic and minerals can be rapidly resorbed position. Therefore, drinks as non-isotonic drinks were analysed and thus shall al ow a fast recov-di verse as sugar-containing soft-using the K-7400S Semi-Micro Os-ery after exhausting sports ac-drinks, their sugar-free counter-mometer. All beverages advertised tivity. In contrast, non-isotonic parts as well as alcoholic and to be isotonic, had osmolality values Plasma osmolality = 290 ± 10 mOsmol/kg drinks as normal cola or beer non-alcoholic beers and many within the range of 300 mOsmol/kg 300 need to be diluted in the intes-more can easily be analyzed. ± 10% (grey bar). Thus, they met tine prior to adsorption. Thus, This renders it a fast and reliable the specifications for isotonic drinks The osmolality of solutions used in the clinical and 200 these beverages rather have a method for both quality control defined by the European Food pharmaceutical field is an important issue that re-dehydrating effect. Since osmo-and for comparing different Safety Authority. In contrast, a usual quires regular monitoring. Especial y infusion solu-lality of the solution is the critical drinks regarding their potential softdrink or an alcoholic beer ex-tions but also solutions for external use like eye 100 feature in this context, an exact beneficial effect. hibited much higher osmolalities. drops and rinsing solutions have to be isotonic to Osmolality (mOsmol/kg) Ringer solution 0.9 % NaCl 5 % Glucose ensure the physical wel -being of the patient. There-0 fore, strict quality control is needed. The K-7400S B E V E R A G E S & F O O D al ows a quick analysis of such solutions and pro-Analysis of isotonic infusion solutions For analysis and quality vides reliable results even with small sample vol-Three commonly used infusion solutions were analyzed control of beverages like umes. Thanks to the broad measurement range, regarding their osmolality. Al of them were in the range isotonic drinks and beer. high osmolality solutions can also be analyzed. of human Plasma (290 ± 10 mOsmol/kg) and thus are P H A R M A C E U T I C S suited for therapy. Physiological saline solution is also For quality control of infusion used for inhalation, rinsing or as eye drop solution. The solutions, inhalation, rinsing correct osmolality is crucial for these treatments as wel . solutions and eye drops. A C A D E M I A For research on plant sap and insect haemolymph and testing of nutrient solution and cell culture media. European Pharmacopoeia I N D U S T R Y The K-7400S Semi-Micro Osmometer com-For process monitoring and plies with the European Pharmacopoeia for quality checks of reagents osmolality (Ph. Eur. 2.2.35). and chemicals. 8 www.knauer.net/osmometry 9 K-7400S Semi-Micro Osmometer Freezing point osmometry Product Art. No. A0006AC K-7400S Semi-Micro Osmometer with Measuring head, incl. calibrat-ing solutions (400, 850 mOsmol/kg), plastic sample tubes and IQ (OQ is available on request) KNAUER is one of the pioneers Accessories & spare parts A0840-2 Measuring head for K-7400S Semi-Micro Osmometer, for plastic sample in the field of osmometry tubes* In many laboratories, the accurate concentration of solved molecules in a liquid is essential for daily A01240 300 mOsmol/kg calibration solution (12 vials) work routine. A01241 400 mOsmol/kg calibration solution (10 vials) The KNAUER K-7400S Semi-Micro Osmometer is ideally suited for this task, since most solutes in A01250 850 mOsmol/kg calibration solution (12 vials) a liquid can be measured. The determination of A01248 2000 mOsmol/kg calibration solution (12 vials) total particle concentration or osmolality becomes fast and simple. A0272 Plastic sample tubes**, 500 pcs KNAUER is one of the pioneers in the field of osmometry and is known for its reliable and A0720 Plastic sample tubes**, 1000 pcs user-friendly instruments for many decades. In A02330 Cleaning tissue, lint free 1962 the company founder Dr. Herbert Knauer invented the company’s first freezing point A3711 Plain paper printer for the K-7400S Semi-Micro Osmometer with power osmometer. Since then the measurement techno-supply and RS-232 printer cable (optional for stand-alone use) logy was continuously adapted and advanced. The latest development in this line of products is A7013 Paper roll (60 m); spare part for printer the K-7400S. Based on proven KNAUER freezing A7014 Ribbon tape; spare part for printer point technology, this new device features the small footprint, the robustness and silent operation A3705 EuroOsmo 7400; recommended software package for the K-7400S of its popular predecessor, but has been improved Semi-Micro Osmometer (optional) significantly in specifications. A13120 Computer for EuroOsmo 7400 incl. monitor and English Windows operating system A13270 Barcode scanner for EuroOsmo 7400 (optional) * The measuring head is downward compatible with ** Sample tube characteristics can impact osmometry the K-7400 Semi-Micro Osmometer (A3707, A3709) results significantly. The plastic sample tubes offered and replaces earlier variants for plastic sample tubes by KNAUER are tested suitable for freezing point (A0840-1) and glass sample tubes (A0840). osmometry. 10 www.knauer.net/osmometry 11 Technical data and prices are subject to change without All trademarks are the property of their respective owners. notice. Prices may vary by country and do not include Our general terms and conditions apply: taxes, customs duties or delivery. www.knauer.net/terms Distributed by: S/1.0/09.19 7716U 018 V ER 2UAN © K KNAUER +49 30 809727-0 Wissenschaftliche Geräte GmbH +49 30 8015010 (Fax) Hegauer Weg 38 info@knauer.net 14163 Berlin, Germany www.knauer.net 12