How to increase the EDTA selectivity?
488590
EDTA selectivity can be changed by altering the pH. Another technique is to use masking. Details can be found in the reference below.
611075
I'm assuming you are extracting from an aqueous solvent?  Preferably, you want to increase the polarity of the aqueous solution, such that the solute has less affinity for water than it would for the organic solvent.  This can be done by "salting" the water (increasing the ionic strength by adding an inert salt, a la NaCl).  You then extract the solute with your organic solvent of choice, usually using smaller aliqouts more frequently vs. larger aliqouts (deals with partition coefficient, or how much will get extracted vs. how much remains in the water).  After extraction, the organic solution is usually dried (more often than not by MgSO4 or Na2SO4) and then the solvent is distilled off to yield hopefully pure product.
53470
Yeah, that's a good suggestion.  \nYou might also want to try stirring with a bulbous glass stirring rod or a rubber policeman very carefully.  Also, I think you'd be okay if you stir without making contact with the paper.  Perhaps the best suggestion, though, would be to pull through a little bit of your sample at a time; that way, your filter can handle pulling almost all of the liquid out of a small sample, then you add more in, etc., until it's all in and dry.
373023
Ultrasonic cleaners might be the best solution.\n\nHere is an excerpt from the source listed below: \n\nAlthough a range of possible alternative products is available today, experience has shown that substitution of TRI is not easy and even not feasible for a number of specific cases, either for technical or economical reasons. For all cases, substitution of TRI needs a thorough evaluation of all process aspects. For this reason we intend to work with the authorities in order to prevent a blanket implementation of forced substitution, and allow sustainable and continued safe use of TRI. \n\nThe alternatives you will probably consider first are the chlorinated solvents perchloroethylene (PER) and methylene chloride (MC). They match closest the technical features of TRI, such as non-flammability, high solvency power, a wide range of material compatibility and excellent drying and recycling properties.\n\nBeside PER and MC, you have probably also heard about other alternatives such as aqueous (water-based) alkaline systems, flammable solvents (e.g. hydrocarbons or modified alcohol based formulations), supercritical CO2 or hydrofluorocarbons (HFCs), etc.\n\nIt is impossible to say definitively which technology is best. That depends on your specific application, on what you are cleaning, which materials you want to remove, the cleanliness required, the variability of the parts cleaned, the throughput to be achieved, the cycle times, etc. \n\nFor example, for the cleaning of parts between two water-based manufacturing steps (e.g. galvanising), aqueous systems may be better, since parts are put into water phase again later and no energy-intensive drying step to remove the water is required. \n\nIf you need to have very clean and dry surfaces (for coating or surface hardening, for example) and if you have a variety of different metals or blind holes, narrow distances and very fine orifices or a lot of residual oil to clean, hydrocarbons or aqueous systems may not clean and dry well enough. In these cases, chlorinated solvents will offer most often the best solution as they are compatible with most materials, have a high cleaning power, are easy to dry, don't leave residual films and are easy to recycle with high quality by distillation. In addition, chlorinated solvents are today best suited to be used in modern closed systems with minimal losses. Their ecological performance has very much increased and, when used in well-operated metal cleaning systems, they outperform aqueous cleaning as long as drying is required. This has been shown by a Life Cycle Analysis carried out by Ecobilan. \n\nPER comes closest to TRI in technical performance and is often the first choice candidate as an alternative to TRI. However, it shows clear inherent technical differences, which need to be taken into consideration. On one side, PER offers a lower volatility and therefore is advantageous to minimise emissions in closed equipment. On the other side, PER has a lower solvency power and is therefore normally used at a higher cleaning temperature to achieve similar performance. This may raise concerns regarding the compatibility with specific metal working fluids and temperature-sensitive parts. \n\nMethylene chloride (MC) shows excellent cleaning properties already at low temperatures, favouring the cleaning of temperature sensitive parts. However, its high volatility makes emission control more difficult and requires special equipment.\n\nHydrofluorocarbons (HFC) and hydrofluorocarbon ethers (HFCE) are very expensive and show very limited solvency power. A thorough evaluation of the global warming potential is also required to choose the adequate product.
43703
How about the red fountain experiment with acids and litmus solutions? mail me at pr4kane@yahoo.com for furhter details on it. u can try electroplating,bleaching by chlorine/so2,the brown ring test with sulphuric acid etc.
98966
I think you can find everythin u are lookin for and more on this site.. good luck!!!http://www.tannerm.com/electrochem.htm
298794
Add magnesium oxide to a citric acid solution perhaps
636906
Functionallizing the EDTA to make a substituted EDTA
667410
try an emulsifier. soap works as a great emulsifying agent
174475
mix it...let NaCl dissolve in water...then let the mmixture evaporate or perhaps bring the mixture into a boil 'til you can see the formation of crystals...   try it... i've encountered such experiment in my chemistry class... im not quite certain of the procedures though...it's two years ago...cant remember it well...^_^
1117539
2400mg Max! Its hard to do coz all process foods have salt.Dont add salt to anything and read labels carefully.Cheese pizza and hamburgers are loaded with salt!Forget fish and chips all together.Look at bread labels, cottage cheese,even yogurt and you will be surprised at the amount of salt they have! The AMA is trying to force the FDA to add a new label to foods.I hope they can do this coz it will be a great help.
513117
use a potato and two different metals as electrodes. The link will help you, do your own homework, or web searching atleast! it was the second link in google for g** sake!
392297
There are many procedures with which to trypsinize cells. All include washing the cell monolayer with TD, or in rare cases, with VE. This removes serum, which contains trypsin inhibitors, and lowers the concentration of both calcium and magnesium, both of which inhibit trypsinization.\n\nI like to rinse the cells with TD, add approximately 1 ml of straight trypsin, rock the dish, aspirate a majority of the trypsin, and then incubate the dish at 37 °C until the cells come off the dish.\n\nSome people put 1 ml of 5 fold diluted, with TD, trypsin on the dish and leave it on. Others do this using full-strength trypsin.\n\nCells vary enormously in how fast they come off the dish. Some cells come off within one minute, some require 15 min. Cells should be trypsinized until they come off the dish, but not longer. Don't rush, but don't over do it.\n\nCells that are extremely hard to dislodge with trypsin should be rinsed with VE prior to trypsinization and then trypsinized in the presence of VE. The EDTA promotes disaggregation. Unfortunately, EDTA is toxic to cells at high concentration--it deprives them of Zn++.\n\nIt is essential to inactivate trypsin and to remove EDTA after you have gotten the cells off the dish. Trypsin inhibition is accomplished in part by trypsin inhibitors in the serum in the growth medium. Bovine serum is a rich source of trypsin inhibitors.\n\nThe best, but most laborious way to reseed cells, is to dilute the suspended cells with medium containing serum and spin them down in the gray table top centrifuge--5/8 speed, 4 min. Then aspirate the supe, resuspend the cells in medium, and reseed them.\n\nA short cut that works with cells that are being seeded at a low cell density is simply to dilute the trypsinized suspension of cells with medium and seed the cells directly.\n\nIf the cells are to be reseeded at a high cell density, the trypsin will not be diluted or inactivated sufficiently and the cells will not attach.\n\nThis is not satisfactory when VE is used because EDTA is growth inhibitory even at low concentrations.\n\nIt is also not satisfactory with chick cells, since they are grown in medium containing only 2% serum and cannot be seeded very sparsely.
809008
is this your school homework,  are there suppossed to be other questions before these because my computer shows them starting from No. 4.\nnway,\n4.  filter the solution while still hot because as the soltion cools crystallization occurs, and you will nloose your product on the fiolter paper.\n5. crystallization can be induced by reduction in temperature i.e put in an ice bath or you can use a technique called seeding where you put a few crystals of the expected substance in the solution, the other method is to increase the concentration of the solution by evaporating it, to saturation point, ensure you do not evaporate it dry.\n6.i do not know what you started with so i can not tell.\n7.slow cooling will definately give bigger crystalls.\n8.sodium chloride reacts with silver nitrate to form a white precipitate, actually silver nitrate solution is used to analyse NaCl in industrial setting.\n\nope you will find these information sufficient.
137292
You didn't really give me too many options with this one.  Increase or increase?  I think I'll have to go with "increase."\nSeriously, if a pipet is dirty, most likely it is contaminated with a salt compound, which would contribute to the density of something you were measuring out with the pipet.
1167345
EDTA is a good chelating agent for Ca+2  but not for Na+
980626
ChemDraw from CambridgeSoft Corporation may be help you. Look at www.cambridgesoft.com