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1.Cleaning the pipette
After rinsing with tap water, soak with chromic acid detergent, the operation method is as follows:
Use your right hand to hold the pipette or the upper end of the pipette in a suitable position, the index finger is close to the upper mouth of the pipe, the middle and ring fingers are spread out to hold the outside of the pipette, the thumb is held in the middle of the middle finger and the ring finger on the inside of the pipette, and the little finger is naturally relaxed; Hold the ear-suction ball in your left hand and hold it in a fist style. Hold the ear-suction ball in your palm with the tip downwards. Be careful not to leak air. Slowly loosen the fingers of the left hand, slowly suck the washing liquid into the tube until the part above the scale line, remove the ear ball, and quickly block the upper mouth of the pipette (pipette) with the index finger of your right hand, wait for a while, then wash Put the liquid back into the original bottle. Rinse the inner and outer walls of the pipette (pipette) with tap water until there are no water droplets, then wash it with distilled water 3 times, and dry the water for later use.
2. Pipette cleaning Tips
The straws of 1mL or more should be scrubbed with a special brush for straws. The straws of 0.1mL, 0.2mL and 0.5mL can be soaked with detergent, and can be cleaned with an ultrasonic cleaner if necessary. Since chromic acid lotion is carcinogenic, it should be avoided as much as possible. If a large number of straws are washed and rinsed in batches, a washing bucket can be used. The tip of the straw is placed in the bucket, rinsed with tap water for several times, and then rinsed with distilled or deionized water.
3. Precautions for the use of pipettes
(1) The pipette (pipette) should not be dried in the oven.
(2) The pipette (pipette) can’t pipette solutions that are too hot or too cold.
(3) The same pipette should be used as much as possible in the same experiment.
(4) After the pipette raises the liquid level, use filter paper to wipe off the liquid on the outer wall of the pipette.
(5) When looking at the scale, the scale of the pipette should be parallel to the eye, and the lowest meniscus shall prevail.
(6) After the pipette is used, it should be rinsed with tap water and distilled water immediately and placed on the pipette rack.
(7) Pipettes and volumetric flasks are often used together, so the relative volume of the two is often calibrated before use. ...
(8) When using the pipette, in order to reduce the measurement error, the starting point should be the top scale (0 scale) every time, and the required volume of solution should be discharged down instead of sucking as much volume as needed.