Coulometer for low level water determination in sample matrix
1 like1,502 views
The 756 KF Coulometer provides automated coulometric Karl Fischer titration for determining low water contents down to the microgram range. It features a backlit LCD screen, integrated printer, methods memory, and interfaces for connecting additional devices. The instrument guarantees accurate and reproducible results for applications such as solvents, industrial products, finished products, and solids using appropriate sample introduction methods and optional accessories like the 768 KF Drying Oven.
Coulometer for low level water determination in sample matrix
- 1. 756 KF Coulometer Water determination right down to trace levels – with full automation capabilities Karl Fischer titrators
- 2. The convincing way of determining low water contents An innovative and comprehensive solution The 756 KF Coulometer continues Metrohm’s estab- lished line of Karl Fischer instruments for the determin- ation of low-level water contents. Despite its compact construction this instrument leaves no wishes unfulfilled. It comes equipped with a built-in printer and two RS 232C interfaces which allow communication with a balance, external printer and/or computer. This latest addition to the Karl Fischer range guarantees accurate and reproducible results even for water contents in the lower micro range. The dialogue languages English, French, German, Spanish, Portuguese, Swedish and LCD screen of the 756 KF Coulometer with curve showing the Italian are standard, as is the backlit screen with its titrated water as m(H2O) in microgrammes vs. the time in seconds graphics capabilities. The screen not only provides a clear presentation of the parameters, but also shows graphically the course of the KF determination as µg water versus time. This facilitates the assessment of the determination and is a great help in method develop- ment and validation. Depending on the amount of data that are to appear on the instrument display, large or small fonts can be selected. A user list can be entered; the name selected from this list appears in the result report, which can be freely configured by simply selecting the lines containing the desired information. Using the optional Remote Box you can connect a barcode scanner and a PC keyboard to the 756 KF Coulometer. Compatible with GLP and ISO 900X, ready for the millennium change With its built-in time clock, the eight-position date (DD- MM-YYYY) and the surveying functions, this instrument will accompany you safely well into the new millennium. You may programme GLP and ISO 900X functions such as service or validation intervals which alert the user in time to the necessary tests. The GLP mode assists you in carrying out the instrument validation. It contains the formula for calculating contents and recovery rates, the latter allowing to assess the systematic error or bias, i.e. 756 KF Coulometer equipped with a diaphragm cell and the deviation from the reference value. 728 Magnetic Stirrer after a water determination in an oil sample The KF reagent can be monitored with regard to the number of determinations carried out, its useful life span, drift value or capacity. Whenever the reagent has to be exchanged the corresponding request is issued auto- matically. To avoid mishaps of any kind there is the ad- One press of a button for renewing the KF solution ditional possibility of setting limits for the sample weight If a Dosino is connected to the 756 KF Coulometer the or volume and for the result. If one of these quantities spent solution can be siphoned off by simply pressing lies outside the set limits, the corresponding warning a button. This starts a preprogrammed sequence which message appears in the display and report and the runs in the background and transfers the titration vessel «Remote» interface emits a signal. contents via the Dosino into the waste bottle. Subse- Backup of user methods is important in a GLP-com- quently, fresh reagent is added to the KF cell. As the patible lab and can be performed using the Metrodata cell does not need to be opened during this operation, VESUV PC programme. VESUV can moreover be used no humidity enters the cell, which therefore is ready for to collect results from one or more instruments and of- the next determination in a very short time. fers extensive database functions. The above liquid handling steps can also be triggered manually using the 703 Titration Stand. 2 756 KF Coulometer
- 3. Easy operation 756 KF Coulometer with 700 Dosino for automatically aspirating the titration vessel contents and adding fresh reagent. Dosino and waste bottle are mounted on the 6.2055.100 bottle support. Flexible but easy to operate – no contradiction in terms! Often it is felt that an instrument offering extensive ca- pabilities cannot be easy to operate. The 756 KF Cou- lometer solves this problem by placing at your disposal an expert and a standard mode. In the standard mode only those functions are accessible that are needed in 756 KF Coulometer with diaphragm-less cell and 703 Titration Stand for adding fresh reagent and aspirating the spent solution routine work. Operation in this mode requires very few keystrokes and is extremely easy. The user methods stored in the instrument ex works allow you to start your water determinations without further ado. Cell with or without diaphragm – the choice is yours The 756 KF Coulometer is available with two genera- tor cell types. The cell without diaphragm requires just one reagent and is virtually maintenance-free. It can be used for a large number of applications. The cell with diaphragm is especially recommended for determining water in aldehydes and ketones, for extremely low water contents and for samples whose conductivity is very low, for example oils. Method memory for many applications Different applications demand different instrument set- tings. If the endpoint has to be adjusted to a different reagent or if an extraction time has to elapse before the start of the determination, the parameters can be adapted via the software and stored as a separate method. The integrated method memory holds about 100 methods. Using the Metrodata VESUV software, additional methods can be transferred to a PC via RS 232C interface and recalled at any time. Generator cells for the 756 KF Coulometer: left without diaphragm, right with diaphragm 756 KF Coulometer 3
- 4. Oven method with new possibilities 768 KF Oven with additional features The 768 KF Oven is used for samples that cannot be intro- duced directly into the KF cell. The new heating tube guar- antees an optimal temperature distribution in the sample com- partment. Temperature control is very accurate. When the 768 KF Oven is used together with the 756 KF Coulo- meter the oven parameters are queried by the KF-Coulometer at the end of the determination and inserted into the result re- port. Thus, apart from the two connecting cables, no additional equipment is required to route the data to the built-in and/or a com- mon printer. 774 Oven Sample Processor – automation unlimited The 774 Oven Sample Processor allows the application of the oven method to a series of liquid or sol- 756 KF Coulometer with 768 KF Oven id samples. Typical samples are crude oil and oil products such as hydraulic oils, multigrade oils and used oils, as well as organic amines, toners, plastics, pharmaceuticals and freeze-dried products. Sample preparation is very easy – just seal the vial using the sealing tool. Contami- nating samples present no problem as contamination is restricted to the sample vial. The instrument lets you achieve substantial savings both in reagents and time. The results are highly precise and detection limits very low. The turntable accommodates up to 35 sealed sample vessels plus one conditioning vessel. The maximum sample volume possible with the «20 mm aluminium seal headspace vials» is approximately 3 mL. The sample to be analysed is moved to the appropriate position, lowered into the oven and the PTFE-coated septum of the sample vessel pierced by two tubes. One of these introduces dry air or an inert carrier gas into the sample vessel, the other serves to transfer the water driven off to the titration cell, which is mounted on the chassis of the 774 Oven Sample Processor together with a 728 Magnetic Stirrer. As with the 768 KF Oven, the parameters of the 774 Oven Sample Processor can be printed out on the 756 KF Coulometer’s built-in printer and/or on a common printer. 756 KF Coulometer with 774 Oven Sample Processor 4 756 KF Coulometer
- 5. Applications The following Application Bulletins cover coulometric KF water determination: Application Bulletin no. Bibliography concerning Karl Fischer water determinations 88 Karl Fischer water determinations 77 Karl Fischer water determination with the KF Drying Oven 109 Karl Fischer water determinations with the KF Coulometer 137 Analysis of edible oils and fats 141 Karl Fischer moisture determinations in gases 142 Determination of low water contents in plastics 145 Coulometric water determinations according to Karl Fischer in insulating oils, hydrocarbons and their products 209 Water determination according to Karl Fischer in pharmaceuticals, with the oven method* 217 Coulometric water determination in brake fluids according to the Karl Fischer method with automatic sample metering 236 Validation of Metrohm KF Coulometers 273 * The volumetric KF method was used for these water determinations (701 KF Titrino). However, they can also be performed easily with a KF Coulometer provided the water content is not too high. Solvents Industrial products, solids The determination of water in solvents can be carried out These virtually always involve very low water contents. simply and quickly with the 756 KF Coulometer: inject The liquid samples listed can all be injected directly. the sample, read off the result, that is it! Even samples Benzoic and salicylic acid must be dissolved first. The that react with the KF reagent can be determined subject KF Drying Oven, available as model 768 or 688, is used to certain preconditions. For ketones and aldehydes for determining the low water quantities in plastic gran- special reagents are available on the market (only for ules. The KF Drying Oven is also used for water deter- cells with diaphragm). mination in other polymer products (plastic films) and Acetic acid Liquid paraffin solids (metal oxides and salts). Water determinations Acetonitrile Nitrobenzene with the KF Drying Oven result in longer determination Benzene Octanol times owing to the modified procedure: The water is Chloroform Petroleum ether driven off thermally, which takes a certain time. How- Cresols Pyridine ever, thanks to the «drift stop» criterion of the 756 KF Cyclohexane Resorcinol dimethyl ether Coulometer, you can be sure that the determination is Dioxan Tetrahydrofuran carried out as quickly as possible and supplies highly Ethanol Toluene precise results. Furan Vinyl ether Benzoic acid Plastic films Glycerol Xylene Freons Plastics granules Hexane Gasoline Salicylic acid Isopropanol Insulating oil Salts Metal oxides Silicone oil Mineral oil Sulphuric acid Finished products Nitrogen These products must be diluted or dissolved before Nonyl phenol determination. In the case of products that do not con- Petroleum tain fats, this is done with methanol. A methanol-chlo- roform mixture is used for the fat-containing products. The water content of the solvent used is determined as a blank value, which is entered and deducted automati- cally when the result is calculated. Aftershave lotion Face lotion Almond oil Lipstick Aperitif Margarine Butter Mascara Coffee cream Mustard Cognac Sun cream Cough syrup Vinegar Day moisturiser Washing up liquid 756 KF Coulometer 5
- 6. Technical specifications Operating modes RS 232 interface KFC Coulometric KF titration 2 separate interfaces, each can be configured for KFC-B Coulometric KF titration with blank deduc- printer, balance or computer connection: completely tion controllable from external control unit BLANK Blank determination Remote I/O lines GLP Validation of the Coulometer Connection for KF drying oven, 774 Oven Sample Processor, robot Endpoint indication With optional 6.2148.000 Remote Box: connection for Voltametric, AC indication barcode reader and PC keyboard Ipol 2, 5, 10, 20 or 30 µA (adjustable) Dosino connection Iodine production For automatic reagent exchange Pulses of variable length and current intensity Ambient temperature Current at the generator electrode Nominal operation range 5 ... 40 °C 100, 200, 400 mA Storage –20 ... 60 °C Titration rate Transport –40 ... 60 °C Max. 2.24 mg H2O/min Safety specifications Determination range Designed and tested in accordance with IEC publication 10 µg to 200 mg H2O 1010, safety class I. Resolution Power connection 0.1 µg H2O Voltage 100...240 V ± 10% Frequency 50 ... 60 Hz Reproducibility Power consumption max. 38 W Sample: water standard from a reagent manufacturer Fuse 2 x T1H 250 V (only to 10 µg < m(H2O) < 1000 µg ±3 µg be replaced by m(H2O) > 1000 µg H2O ±0.3% or better Metrohm Service using the same type) Drift compensation Additional electronic Automatic, manual or none overload protection Materials Dimensions Housing Powder-coated metal Width 145 mm Keypad cover Polycarbonate (PC) Height 194 mm Depth 307 mm Screen Graphical LCD, 192 x 64 dots, backlit Weight, including keypad Field: 100 x 37 mm Approx. 4.5 kg Printer Built-in thermal printer Paper width 57 mm 144 pixels or 24 characters per line Memory Method storage for approx. 100 methods Silo memory for sample data and results Stirrer control Switching on/off either manually or coordinated with the titration process 6 756 KF Coulometer
- 7. Ordering information, options Ordering information 756 KF Coulometer Microprocessor-controlled Karl Fischer titrator with coulometric reagent generation for KF moisture determinations down to the lower microgram range in liquids, solids and gases. No titre determination required; with integrated printer – Backlit LCD screen (graphical display) – Easy to operate thanks to dialogue in English, French, German, Spanish, Italian, Portuguese, Swed- ish – Internal memory for up to 100 methods – With two bi-directional RS 232C interfaces (DB9) for balance, printer, PC – Connection possibility for PC keyboard and barcode reader – Option: Aspirating and adding fresh reagent by connecting a 700 Dosino 2.756.0010 including titration cell with diaphragm, 728 Magnetic Stirrer and extensive accessories 2.756.0110 including titration cell without diaphragm and extensive accessories (without stirrer) The titration stand or magnetic stirrer is to be ordered separately: 2.703.0010 Titration Stand with magnetic stirrer and pump for addition of solvents and siphoning of titration vessel contents 6.1439.010 Tube for addition or siphoning with the 703 Titration Stand (cell without diaphragm) 6.1805.200 Additional PTFE tubing with two M8 screw nipples for 703 Titration Stand 2.728.0010 Magnetic Stirrer Options 2.768.0010 768 KF Drying Oven Auxiliary instrument for driving off the moisture of solid and liquid samples containing interfering or insoluble compounds. May be used with any volumetric or coulometric KF titrator. Automatic motor- driven sample transfer, built-in air pump and two gas drying flasks, external gas connection (e.g. N2), including accessories. Accessories, consumables and spare parts for 768 KF Drying Oven 6.2141.010 Connecting cable for 768 KF Drying Oven (for automatic operation) 6.2125.110 Additional connecting cable for 768 KF Drying Oven (for report printout on 756 KF Coulometer) 6.1830.000 Heatable outlet tubing 6.1446.170 Stopper for heatable outlet tubing 6.1448.040 PTFE-coated silicone rubber septum (set of 5 items) 6.2415.000 Sample boat made of glass 6.2623.000 Aluminium inserts for the sample boat (set of 25 pieces) 6.2811.000 Molecular sieve, diameter 2 mm, pore dimension 0.3 nm, 250 g 6.2041.180 Instrument bridge for work with the 768 KF Drying Oven 6.5615.000 Equipment for measuring the sample temperature inside the 768 KF Drying Oven using an independent method (validation); with thermocouple, but without measuring instrument for type K thermocouples 2.774.0010 774 Oven Sample Processor Highly flexible instrument combining sample changer, oven and gas pump. Accommodates 35 sample vessels (20 mm aluminium seal headspace vials) and one conditioning vessel. Programming and manual operation via keypad equipped with a two-line LCD display. Including extensive accessories. Remote Box, bottle support and connecting cables for PC, printers and balance 6.2148.000 Remote Box for connecting barcode reader and PC keyboard 6.2055.100 Support for two bottles, each max. 1 L, height adjustable; for reagent and waste bottle when using the 703 Titration Stand (not required when using the 700 Dosino and 6.5617.000 equipment, which contains the 6.2055.100 bottle support) 6.2125.110 Connecting cable for PC with 25-pin connector (DB25) 6.2134.040 Connecting cable for PC with 9-pin connector (DB9) 6.2134.050 Connecting cable for Citizen iDP56XRS, Epson LX, LQ, FX 6.2134.110 Connecting cable for Seiko DPU 414 (DB9) 6.2134.060 Connecting cable for Sartorius balances MP8 and MC1 (RS 232) 6.2125.020* Connecting cable for Mettler balances AE 011/012 and for AND balances (use Mettler cable ME 33995 for Mettler balances AM, AT, PM and Mettler interface LC-RS25 for Mettler balances AB, AG) 6.2125.080* Cable for Precisa balances * Requires 6.2125.010 adapter cable 25 pin to 9 pin 756 KF Coulometer 7
- 8. Ordering information, options Dosino and Dosing Unit for liquid handling (cell without diaphragm) 2.700.0020 Dosino Burette drive with fixed connecting cable (mini DIN connector), to be mounted directly, together with the Dosing Unit, on reagent bottles with GL45 thread. Aspirates spent titrant and adds fresh reagent from the 756 KF Coulometer’s cell 6.5617.000 Equipment for aspirating the cell contents, including 50 mL Dosing Unit and 6.2055.100 support for two bottles Metrodata «VESUV» 6.6008.200 Metrodata «VESUV© 3.0», for up to 64 instruments 6.6008.500 Metrodata «VESUV© 3.0», for 2 instruments PC programme (Windows 95™, Windows NT™) for collecting titration data via RS 232C interface, storing of methods, printout of results, curve representation and recalculation of data. Database func- tions: filtering, searching and inquiries, data export (Excel, Lotus, LIMS, ...). Dialogue in English or German. 6.6008.205 Metrodata «VESUV© 3.0» demo version, for up to 64 instruments Demo versions are original versions with a time span of 100 days after installation. After the trial period you can purchase the «Hardware Dongle VESUV» to obtain unlimited user rights. 6.2145.050 «Hardware Dongle VESUV», for operation with 2 instruments 6.2145.040 «Hardware Dongle VESUV», for operation with up to 64 instruments 8.756.6003 Subject to modifications Printed by Metrohm Ltd., CH-9101 Herisau, Switzerland 2004-10 8 756 KF Coulometer