A summary of the preparation experience of thin layer analysis experimental thin sheet.

related topics . The preparation of thin sheet summary experience summary 1.CMC-Na configuration is also more important, can not be too thin, otherwise silicone adhesion is not good, paved silicone easy to fall off. Too thick also can not, not easy to mix with silicone 2.CMC-Na and silicone mixing attention ratio, generally 30 grams of silicone added 100 grams of 0.3-0.5% CMC-Na aqueous solution. If there is more paving, you can feel the degree of suitability with experience. Mixing is best in one direction, so it is not easy to have bubbles 3. The uniformity of the paving plate. This is also an important aspect related to the good or bad of the board. In order to make the thin sheet silicone uniform, lay the glass plate on the table carefully upside down, to ensure that the thin sheet all places are equal..4. The thickness of the paving board is different for the individual. Some spread thicker, this situation CMC - Na can not be too thin, otherwise silicone clamor off. Thick plates expand more slowly, but the dosing can spread more easily. Thin plate unfolds relatively quickly, easy to spread point sample quantity should be5. Thin sheet of active. Reification must be laid out and dried and put in
oven
to resuscerate. Dry means you can't see water marks on it. Generally can choose the evening paving board, in the morning just thin sheet has dried, can be put into the oven to live. Why do you have to do it completely to be alive? If not completely dry will cause the thin sheet silicone to crack when it is active.
preparation of thin sheets sums up personal experience Summary 1: .Hand-paved board is a very test of your endurance things, it is best to find the laboratory GGJJMMDD together, one to speed, two to exchange ideas together.I think the first key point is that your CMC-Na solution has to be well-made, well placed, and completely layered and can only be cleaned. The liquid should be clarified transparent, too long CMC-Na may yellow, if mold appears, absolutely not used.second is that the ratio of silicone to CMC-Na solution can be adjusted appropriately, fine-tuning according to the softness and hardness of the sheet you need. Can be grinded by one person, one person slowly inverted CMC-Na solution. Grinding is the most test of your ability, I think you should find girls to grind, but that kind of too weak can not.
grinding should follow a direction, the speed should not be fast, to follow the edge of the research, observe carefully, must kill the bubbles. Grinding good cause change is uniform, no bubbles, no solid powder foreign body, the solution has a certain viscosity., the floor, I think everyone likes, can fall down the middle of the board, can also fall down a certain edge, when you should also pay attention not to introduce small bubbles. You can use the glass rod to lead the solution tiled on the glass plate (by the way, the glass plate should be very clean, no scratches, no gaps, 4 corners to "sound"), if necessary, you can use 10 fingers to drag the glass plate, rhythmic reversal, so that silicone sharing homogeneity.
especially 4 corners, easy to be higher than other parts of the glass plate, so pay special attention. Upside down the plate, the surface should look smooth and flat, no pores.the paved board, to find a clean place to dry, this process is also patiently waiting for it, do not disturb!dry naturally, live (about 105 degrees Celsius for 40 minutes) and store in a sealed
dry
dryer.want to say, if you lay the board for the purpose of seat analysis, it must be very careful. If only natural pharmacy that kind of rough check the fractional purity obtained by the column, then there is no need to be so complex, that is to say, the speed can be faster, the requirements of the board does not need to be so high!to see more of their own how to lay, practice hands, must become a master!
preparation of thin sheets summarizes personal experience summary II: .(1) CMC-Na solution can no longer be boiled with cold water, otherwise, a few days later will turn green, moldy. (2) If you have a filtering device you can filter the CMC-Na solution directly, you don't have to wait for it to precipitate and then take the liquid (hey hey, I'm an acute son), there are two benefits one is to save the CMC-Na solution, and the other is to reverse the filtered CMC-Na solution without having to worry about pouring out the insoluble of the lower layer!)
work experience of my thin layer analysis board: . 1. Preparation of 4% to 5% of methyl cellulose (CMC): called CMC, dissolved in cold water, side
heating
stirring, until it becomes a clear, transparent solution. . 2. 40% silicone: according to the amount of CMC solution, according to 40% of the proportion of thin sheet layering silicone, poured into the large research, mixed with THEC solution, fully ground into a uniform paste. . 3. Add a few drops of ethanol or butanol to de-foam. . 4. Place the slide on the platform and spoon the paste silicone and spread it evenly over the surface of the slide. . 5. After natural drying, put in the oven and bake for more than 12 hours. It is then active at 105 to 110 degrees C, and the processing time is 0.5 to 1 hour, which can be used after cooling. I'll talk about my little experience, too. CMC-Na: Silicone for 2.5:1 is better, upstairs brother said 3:1 should also be possible, but silicone with too thin consequences are very serious, the board in drying will appear many cracks, like life-like flowering, completely useless.
This is my painful experience, at that time did not know is the reason for silicone too thin, but also thought that the winter too cold board to freeze and crack, and made a batch placed in the heating room, or cracking not. Wasted a whole bottle of GF254 (do a lot of preparation board usage). have a problem so far do not understand, please ask you prawns, drying plate in the oven how to completely crack, what way to avoid the plate cracking. brother upstairs, I had the same experience. At that time, the board was too thick, and then it would be better to lengthen the grinding time. first of all, I would like to say that hand-paved board, only suitable for qualitative analysis, not suitable for separation of quantitative. The main points of hand-paved board I think there are the following points: 1. Hand-paved board is commonly used: silicone G board and silicone CMC board. The former is calcined gypsum (the gypsum is baked at 140 degrees C for 3-4 hours) and silicone according to 1-1.3:10 mixed evenly. Each serving of silicone G plus water 2-3 parts into a paste, you can use. The operation of the latter has been discussed by the prawns. . 2. The carrier requires smooth cleaning. Before use must be treated clean, wash with washing liquid or soapy water, and then rinse with water, dry; . 3.CMC-Na to use distilled water as a solvent, after heating dissolved, cool, preferably filtered for use;
deboulant
can be mixed directly with CMC-Na solution; . 4. When I do, first add CMC solution in the research, then add silicone, grind in the same direction, so that it is easier to smooth the hard-to-encumbase silicone particles;
.