Capillary pipette

In order to indicate the accuracy that can be obtained from a capillary pipette, one may refer to the so called Sahli pipette, which is approximately 80 mm from mark to tip. This pipette is used as a washout pipette and can measure samples which are readily reproducible to 1 part in 80, since it is a relatively simple thing for the eye to see 1 mm. On the other hand, if one places a bulb in the tube, and cuts the bore down at the mark by 30%, then this would decrease the error by a factor of 4. It is thus practicable to sample from a micropipette, which is used as a washout pipette, with greater accuracy than one can sample from a conventional macro pipette, which delivers 1 ml by blowout, or to deliver. Figures5 and 6 illustrate various designs of micropipets (13,14). 

The viscosity of gelatin solutions is vital to the control of the thickness of the cast film. Viscosity is measured on a standard 6 % w/w solution at 60°C in a capillary pipette and generally the range of 30-60 millipoise is suitable. 

Capillary pipette Falling sphere Parallel plate Falling coaxial cylinder Stress relaxation Rotating cylinder Tensile creep... 

According to Claude Bernard the action of anesthetics is very general. They react not only with animals but also with plants. Bose has found that plants anesthetized with ether go through a preliminary period of increased irritability or stimulation. A dilute alcohol solution acted as a stimulant, whereas a concentrated alcohol solution acted as a depressant. Nichols applied chloroform to the wall of an intemode of Nitella by means of a capillary pipette. An area of non-motile protoplasm was produced at the point of application of the anesthetic. This area of non-motile protoplasm resumed its movements later, so the process appears to be a reversible one. Nichols considers the effect to be due to gelation, thus providing us with a case of reversible coagulation in plants accompanied by anesthesia of the part affected. 

With a fine capillary pipette drop some of the liquid into a large beaker of water, observing the formation of vortex rings. 

When the volume of solvent required for the recrystallisation is large, compared to the quantity of solid material, initial removal of mother-liquor from the centrifuge tube by this capillary pipette method may be tedious. In such a case, centrifugation should be more prolonged to get more effective packing of the... 

The column may be loaded by the technique of dissolving the liquid or solid in the minimum volume of solvent, and by means of a capillary pipette distributing this solution evenly on to the top of the column and allowing the solvent to... 

A useful LC modification is the quick clean-up column. The simplest of this is a capillary pipette plugged with glass wool and partially filled with packing material. The dry packed column is wetted with solvent, sample is applied, and... 

Table VI.12 Separation of Group I cations on the semimicro scale The residue may contain PbCl2, AgCl, and Hg2Cl2. Add 1 ml hot water to the ppt., place the tube in a boiling water bath for 1-2 minutes, and stir continuously. Centrifuge rapidly separate the solution from the residue with a capillary pipette and transfer the clear solution to a centrifuge tube.

The position of AB (usually a pencilled line) is fixed by applying a drop of the solution from a capillary pipette or micro syringe along the line. The distance moved by the substance or ion is generally taken as the distance between the line AB and the centre of gravity of the band the resulting RF value does not take into account the width of the band and also some uncertainty may be introduced if the band has diffuse boundaries. 

Nanomat in combination with Capillary Dispenser Camag offers the advantage of easy application of sample onto TLC and HPTLC plates or sheets in the form of a small spot. The capillary pipettes, filled with sample solution, are loaded into the dispenser in magazines having closely controlled tolerances and inertness, and the tip of the capillary cannot damage the surface of the layer because it is lowered precisely onto the layer at a selected position. The capillary touches the thin layer with a constant pressure, which is determined solely by the friction against a permanent magnet. 

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