The Dosino from Metrohm is suitable for the preparation of demanding and/or toxic standard solutions in GLP/GMP- and FDA-regulated laboratory surroundings.
Dosino technology applies the piston buret concept 'upside down', meaning the drive is located above the high-precision glass cylinder.
Using this concept means that in case of a leak, the substances to be dosed out, some of which are aggressive, can no longer damage the drive.
The dosing units of the 800 Dosino can be mounted directly on bottles and canisters equipped with GL 45 strew heads.
Adapters are available for the other types of threads.
The ceramic disk located beneath the glass cylinder serves four freely definable ports for dosing functions.
The glass cylinder can be emptied completely; the remaining dead volume is extremely low.
The whole procedure is not affected by air bubbles.
The Dosino can also aspirate defined volumes of several solutions (and air), mix them, dilute them and dose them.
This results in numerous possibilities for PC-controlled laboratory dosing.
Preparative work with metal-organic compounds, which are extremely important in organic synthesis, is usually only possible in the absence of air, as they tend to react violently with moisture or oxygen.
This means that the whole synthesis apparatus, including all connections to the Dosino, must be thoroughly purged with a protective gas after a previous check for leaks.
In the majority of applications, organo-magnesium and organo-lithium compounds and occasionally also silicium tetrachloride are added to carbonyl compounds.
The dosing rates of the organo-metal compounds are in the range 0.1-2mL/min; dosing times are from 2-5 hours.
The dosing system can easily be transported from one synthesis apparatus to the next.
The preparation of calibration standards is a frequent source of error, particularly in shift work with changing personnel; this is usually caused by pipetting inaccuracy and insufficiently cleaned volumetric apparatus.
By using an automated dosing system consisting of the 800 Dosino, 846 Dosing Interface and 840 Touch Control, individual errors are avoided by the user-independent preparation of the standards.
In addition, contact with harmful substances is also reduced.
A sample assignment table ensures that samples with their own sample identification are automatically processed by the correct method.
Repetitive identifications, such as occur in the preparation of external calibration standards, are saved in text templates and can be used again at a later date.
For the preparation of a defined concentration of internal standard, automatic standard addition is carried out after previously weighing out the sample.
An individualised operator interface allows the amount of information that a window contains to be freely definable; this means that the user can only see the functions that are required.
In order to increase the robustness of the system, the touch-sensitive control is used in preference to PC control.
In the determination of paracetamol, caffeine and propyphenazon in analgetics, the 800 Dosino can be used in combination with the 815 Robotic Filtration Soliprep as a sample preparation system for HPLC.
The tablets are automatically treated with eluent and then pulverised by a homogeniser.
The resulting suspension is stirred for a few minutes before it is filtered through a disposable filter into a PP sample vessel or vial.
The control of the dosing, filtering and sample changer operations, some of which are carried out in parallel, is via Tiamo, the laboratory automation and titration software.
Further applications of the various Soliprep systems cover the determination of water and benzbromaron in tablets, the determination of the CTAB surface (adsorption of N-cetyl-N,N,N-trimethyl ammonium bromide) of silica gels or soot and many more.
The 800 Dosino controlled by Tiamo (parallel operation) or Touch Control (single or tandem operation) can be used universally for dosing and liquid-handling tasks in both the analytical laboratory or directly in the synthesis laboratory.
