Matters Needing Attention when Using Hawach Pipette
Hawach pipette in the study of analytical testing, generally using a pipette to measure a small amount or a small amount of liquid. The correct use of the pipette and some of its details are ignored by many people.
Pipette range adjustment – when adjusting the range, if you want to adjust from large volume to small volume, follow the normal adjustment method, turn the knob counterclockwise; but if you want to adjust from small volume for large volume, you can rotate the scale knob clockwise to the scale beyond the range, and then adjust back to the set volume, so as to ensure the highest accuracy. During this process, never push the button out of the range, otherwise, it will get stuck in the internal mechanism and damage the pipette.
Pipette Pipetting method – Before pipetting, ensure that the pipette, tip, and liquid are at the same temperature. In the process of sucking the liquid, the pipette should always be in a vertical state, and then insert the tip into the liquid surface 2-3 mm. However, before aspirating, it is possible to first absorb the liquid several times to wet the liquid suction nozzle, especially when sucking a liquid that is thick or different in density from the water. Both forward and reverse pipetting methods can be used at this time.
The first is the forward pipetting method. Press the button to the *stop with your thumb, then slowly release the button to return to the origin. Then press the button to *stop to discharge the liquid, and then stop for a while and continue to press the button to the second stop to blow out the residual liquid. Finally, release the button.
The second is the reverse pipetting method. This method is generally used to transfer highly viscous liquids, biologically active liquids, easily foaming liquids or very small amounts of liquids. This method is generally used to transfer highly viscous liquids, biologically active liquids, easily foaming liquids or very small amounts of liquids. Press the button first to the second stop and slowly release the button to the origin. Then press the button to *stop to discharge the liquid with the set range, continue to hold the button at the *stop point (do not press down again), remove the pipette head with residual liquid, and discard it.
The correct placement of the Hawach pipette-use it, you can hang it vertically on the pipette holder, but be careful not to fall off. When there is liquid in the pipette tip, do not place the pipette horizontally or upside down to prevent the liquid from flowing back to corrode the piston spring.
Hawach pipette maintenance:
1. If not used, adjust the range of the pipette to the maximum value to keep the spring in a relaxed state to protect the spring.
2. Periodically clean the pipette. It can be washed with soapy water or 60% isopropanol, distilled water, and dried naturally.
3. Before high-temperature sterilization, make sure the pipette can adapt to high temperatures.
4. Calibration can be carried out by repeatedly weighing distilled water in a 20-25 degree environment.
5. Check if there is any leakage during use. The method is to take the liquid and then hang it vertically for a few seconds to see if the liquid level drops. If there is leakage, the reasons are as follows:
(1) Whether the pipette heads match;
(2) Whether the spring piston is normal;
(3) If it is a volatile liquid (as is the case with many organic solvents), it may be a problem of saturated vapor pressure. You can suck up the liquid several times before pipetting.