Views: 22 Author: Site Editor Publish Time: 2020-09-09 Origin: Site
Pipettes and pipettes are essential glass instruments commonly used in laboratories. The name pipette has gradually disappeared, and it has been changed to a multi-scale pipette. However, for the sake of table difference, this article still calls the pipette. Many people say that a pipette with a scale is called a pipette, and a pipette without a scale with a glass belly is called pipette, is it true?
(1) Pipettes are pipettes. Commonly used pipettes have specifications such as 1ml, 2ml, 5ml, 10ml, 15ml, 25ml and 50ml, which are necessary measuring instruments in quantitative tests. The internal volume pipette and the pot-bellied pipette are similar in length.
(2) The pipette is a graduated pipette, a glass tube with sub-scale. Commonly used straws are 1ml, 2ml, 5ml, 10ml and other specifications.
(3) The internal volume pipette means that the volume of all liquid in the pipette is consistent with the scale. The usual pipette scale marks the volume of the "flowing out" liquid. This pipette is suitable for ordinary solutions with low viscosity. For liquids with high viscosity, because there are many residues on the inner wall of the tube, the scale marked on the tube is generally the entire volume of the tube. Generally, the inner wall of the pipette is rinsed with a solvent after aspiration, so the volume indicated on the scale of the inner volume pipette is slightly smaller than the commonly used "external volume" type.
(4) Before pipetting the solution with a pipette or pipette, use filter paper to absorb the water inside and outside the tip, and then rinse with the solution to be piped 2-3 times to ensure that the concentration of the pipetted solution remains unchanged. When pipetting the solution, insert the lower tip into the solution 1-2cm to suck the solution. When the liquid level of the sucked solution rises above the mark, lift the pipette, remove the solution from the end of the pipette with a clean filter paper, and slowly put it down The solution reaches the scale of the pipette, and then insert the pipette into the vessel that receives the solution, with the end of the pipe still against the inner wall of the container. At this time, the pipette should be vertical, and the receiving vessel should be tilted so that all the solution in the pipe naturally stays along the wall of the vessel. After waiting for 10-15 seconds, take out the pipette.
(1) In terms of specifications: because the pipette has only a few fixed specifications, its use is limited. The pipette can basically be taken at will, so it is widely used. It also depends on the accuracy required by your experiment. Generally, selecting a suitable pipette for analysis experiments can also meet the requirements.
(2) On the scale: the pipette has a full scale, and the pipette only has a full scale. The pipette is prone to errors in operation. The pipette is a one-time operation with small errors.
(3) In terms of accuracy: a pipette with a scale is called a pipette, and a pipette with a glass belly is also called a single-label tube. The pipette is more accurate than the pipette. Especially when pipetting 20 or 25 ml volume of solution, there is a big error when using a graduated pipette to take several times! Do it all at once with a pipette!
(4) Measuring out and measuring in: The pipette is used to accurately pipette a certain volume of solution. The pipette is a measuring instrument that is only used to measure the volume of solution it releases. The pipette is a straight glass tube with graduations to know the volume of liquid. According to JJG196-2006, the type mark on the pipette: measuring input: In; measuring output: Ex; blowing out: Blow out. The pipette belongs to precise pipetting and is more complicated to use; the pipette is relatively rough and simple to use. So the laboratory needs to use them in different situations.
The internal volume pipette means that the volume of all the liquid in the pipette is consistent with the scale. The usual pipette scale marks the volume of the "flowing out" liquid. This pipette is suitable for ordinary solutions with low viscosity. For liquids with high viscosity, because there are many residues on the inner wall of the tube, the scale marked on the tube is generally the entire volume of the tube. Generally, the inner wall of the pipette is rinsed with a solvent after aspiration, so the volume indicated on the scale of the inner volume pipette is slightly smaller than the commonly used "external volume" type.
The internal volume pipette is an ordinary pipette. The difference is that the former is a measurement operation and the latter is a measurement operation during calibration. Need to record the correction value, and add the correction value in the calculation. It is often used for the sampling of viscous samples. After sampling, wash and transfer with an appropriate amount of solvent.
(1) Ordinary pipette: The volume of the "flowing out" liquid is marked on the scale of the ordinary pipette. This kind of pipette is suitable for the usual solution with low viscosity.
(2) Inner volume pipettes: Inner volume pipettes are used to pipette viscous liquids. They are metered-in pipettes and need to be washed with solvent several times. The washing liquid is combined and placed in a volumetric flask, and then diluted with solvent to the mark , Matching. For example, if the marking scale is 2ml, then the volume of the liquid absorbed to the scale is exactly 2ml, and the liquid adsorbed on the tube wall should be washed off with a solvent after releasing.
The internal volume pipette means that the volume of all the liquid in the pipette is consistent with the scale. For liquids with high viscosity, because there are many residues on the inner wall of the tube, the scale marked on the tube is generally the entire volume of the tube.
The content volume pipette also has a big belly. There are two main differences: 1. It can be rinsed; 2. Theoretically, you should just suck the scale line when you aspirate liquid. If you suck it above the scale line and then put it on the scale line, it won’t be accurate. Up. Generally, the inner wall of the pipette is rinsed with solvent after aspiration. Therefore, the volume indicated on the scale of the internal volume pipette is slightly smaller than the commonly used "external volume" type.
