What is a good way to clean the pipette tip of the laboratory
Pipettes are the most commonly used consumables for quantitative analysis experiments in our laboratory. But in the laboratory, if the pipette tip has a small amount of impurities, it will affect the accuracy of the experiment. Today, the editor of GONGODNG invited the laboratory staff to talk about what are the good ways to clean the pipette tips of the laboratory?
1. Mixing ratio of special washing liquid for pipette tips:
The washing solution is a saturated solution of potassium dichromate in concentrated sulfuric acid. (5g of crude potassium dichromate is dissolved in 10mL of hot water, slightly cold, and slowly added to 100mL of concentrated sulfuric acid under stirring to obtain chromic acid washing liquid, referred to as washing liquid).
Pipette washing liquid has a strong decontamination ability. When washing, add washing liquid to the container, the amount of which is 1/3 of the total volume of the container, then tilt the container, slowly turn the container, so that the inner wall of the container is all Wet the liquid, then pour the lotion into the original bottle, and then wash off the lotion with water. If you can soak the container for a period of time with a lotion or heat it, the effect will be better.
2. When cleaning laboratory pipettes, we should also pay attention to the following points:
①. It is best to wash the container with water or detergent before using the lotion.
②. Before using the lotion, try to remove the water in the container as much as possible to avoid diluting the lotion.
③. After use, the lotion should be poured back into the original bottle, and the lotion can be reused.
④. Do not use the washing liquid to wash the reducing dirt (such as some organic matter), these substances can reduce the potassium dichromate in the washing liquid to chromium sulfate Green); the lotion that has turned green cannot be used anymore.
⑤. The lotion is very corrosive, it will burn the skin and damage the clothes, please be careful when using it. If the lotion is accidentally spilled on the skin, clothing and laboratory table, it should be rinsed with water immediately.
⑥. Because potassium dichromate seriously pollutes the environment, the washing liquid should be used as little as possible. After washing the container by the above method, the detergent is also washed away with water. And washed three times with distilled water.
3. When washing the container, it should meet the principle of a small number of times. Not only saves but also improves efficiency. Wiping the cleaned container with cloth or paper can not only make the container clean, but will leave the fibers on the wall of the container and stain the container. There should be no insolubles or oil stains on the cleaned container walls. Such walls can be completely wetted by water. When checking whether it is clean, turn the container upside down, and the water flows down the wall of the container, leaving only a thin and uniform film of water on the wall, without water drops; if there are water beads, it is not washed net.