When using a laboratory bench, you will often encounter some unexpected "trouble", such as the cork is stuck and can not be opened, the instrument on top of the dirt is difficult to remove, as well as the separation of liquids when the emulsion occurs and so on. If you can take the appropriate methods or techniques to deal with these problems will be solved.
When the grinding part of the glass instrument cannot be opened because it is stuck, the following methods can be used to deal with it:
1. use a wooden tool to gently tap the side of the grinding port so that it will gradually loosen and detach due to vibration. For the reagent bottles that are stuck, the ground stopper of the dispensing funnel, etc., the stopper of the instrument and the mouth of the bottle can be stuck in the corners of the laboratory bench or wooden table, and then gently knock with a wooden tool along the direction of about 70 ° angle with the axis of the instrument, and at the same time rotate the instrument intermittently, tap and at the same time intermittently rotate the instrument, and repeat this operation a few times, usually stuck with a less serious grinding can be opened.
2. heating some of the sticky abrasions, it is not convenient to knock or knock ineffective, the sticky part of the outer layer can be heated, so that its thermal expansion, and separation of the inner layer. For example, with a hot damp cloth "hot" bonding part, with a hair dryer or swimming flame baking abrasive part.
3. Penetration Some abrasive ports are firmly bonded due to chemical corrosion, or are complex and expensive instruments. They are not suitable for tapping and heating. Water or dilute hydrochloric acid can be opened after soaking for a few hours. When the instrument is in urgent need, a penetrating organic solvent such as benzene, ethyl acetate, petroleum ether, sodium dioctyl sulfosuccinate, etc., can also be added dropwise to the gap between the grinding ports to penetrate and infiltrate the adhered surfaces. parts, thus separating from each other.
2. Open the tight screw cap
When you can't screw the bottle cap, use hairdryer or small fire to bake around the cap to make it expand by heat, and then wrap the cap with cloth to unscrew it with force.
If the bottle is filled with unsuitable heat or flammable substances, it is recommended to take a strong rope, one end of which is tied on top of a fixed object such as a door or window handle, and then wrap the rope around the bottle cap in a clockwise direction, and then pull the rope tightly with one hand. At the other end, hold the bottle with one hand and push it forward to open the cap.
3. Take out the thermometer stuck by the rubber stopper
When the thermometer or glass tube is stuck with the rubber stopper or tube and difficult to take out, use a small screwdriver or knife tip to insert it between the thermometer or glass tube and the rubber stopper or tube to form a gap, and then put in a few drops of water, operate in this way and unfold it around the thermometer or glass tube, and it will soon be taken out while gradually deepening. You may also use a drill that fits the thermometer or glass tube, dip it in a little glycerine or water, and put it in through the end of the thermometer, applying gentle pressure, and pushing as you turn it. When it is difficult to turn, pull it out and then dip it in lubricant . After several repetitions, the thermometer or glass tube can be removed.
4. Remove special dirt on instruments
When the glass instrument on the adhesion of special dirt, with the general washing method is difficult to remove, should first distinguish the nature of the dirt, and then targeted treatment.
For water-insoluble acidic dirt, such as organic acids, phenolic deposits, etc., can be cleaned after soaking in lye. For water-insoluble alkaline dirt, such as metal oxides, scale, etc., can be cleaned after soaking in hydrochloric acid. In case of potassium permanganate deposits, it can be cleaned with sodium sulfite or oxalic acid solution. Manganese dioxide deposits can be dissolved with concentrated hydrochloric acid. In case of staining with iodine, it can be soaked in potassium iodide solution. Silver nitrate stains can be cleaned after soaking with sodium thiosulfate solution. Silver or copper mirror after the reaction of silver or copper mirror, add dilute nitric acid, a little heat can be dissolved. Tar or resin stains can be soaked in organic solvents such as benzene and esters, and then cleaned by ordinary methods. For the above methods can not be cleaned glass instruments, can be used dilute hydrofluoric acid wetting the edge of the dirt, dirt will be etched with the thin layer of glass off, and then cleaned with water.
