LKL Posted June 27, 2005 Share Posted June 27, 2005 Any ideas what chemical(s) might be used to completely dissolve a grain of wheat, including the husk. It doesn't matter if the carbohydrates/proteins/cellulose are altered in the process since the aim is to study natural radionuclide levels in foodstuffs (my mother's new job). Any help will be greatly appreciated. Link to comment Share on other sites More sharing options...
EL Posted June 27, 2005 Share Posted June 27, 2005 Any ideas what chemical(s) might be used to completely dissolve a grain of wheat' date=' including the husk. It doesn't matter if the carbohydrates/proteins/cellulose are altered in the process since the aim is to study natural radionuclide levels in foodstuffs (my mother's new job). Any help will be greatly appreciated.[/quote'] In academy, that step in the process of chemical analysis is called meal-digestion. This means that you should expect to simulate nature. The first thing to do is to mechanically prepare the sample by smashing it in a mortar or in a modern grinder. The second step is weighing the dry sample before adding distilled water and the digestion chemicals. The third step is to choose the path of digestion, whether it would be enzyme aided or acid-base-boiling aided. If you were looking for a non destructive method for dissolving whole grains, then I am sorry to inform you that such a method does not exist. Proteins and carbohydrates within the wheat grains (less the cellulose husk) may readily swell in cold water and form a gelatinous mixture, which shall coagulate and increase in the degree of polymerization on any heat treatment. Thus, for any proper dissolution, you need to reduce the molecular weight of the mixed components by Digestion. Link to comment Share on other sites More sharing options...
Hephaestus Posted June 28, 2005 Share Posted June 28, 2005 cellulose can be dissolved in some new ionic liquids such as 1-allyl-3-methylimidazolium chloride and 1-butyl-3-methylimidazolium chloride where solubility is better in the first solvent. Try the sigma aldrich catalogue for ionic liquids. Link to comment Share on other sites More sharing options...
YT2095 Posted June 28, 2005 Share Posted June 28, 2005 Nitric acid will work also, but the product left over is explosive unfortunately, so care must be taken when dissolving this in acetone and in it`s disposal. Link to comment Share on other sites More sharing options...
EL Posted June 28, 2005 Share Posted June 28, 2005 cellulose can be dissolved in some new ionic liquids such as 1-allyl-3-methylimidazolium chloride and 1-butyl-3-methylimidazolium chloride where solubility is better in the first solvent. Try the sigma aldrich catalogue for ionic liquids. Indeed. And in fact rather than the impossible "solvent of whole wheat grains", it would be a best advise to use step solvent extraction methods, where cellulose and unbranched glucans may be dissolved and separated in several ways, that include: separation of amylose leaching from starch granules during gelatinisation, centrifugation of retrograded amylose, removal of amylopectin branches by enzymes, removal of amylopectin from starch solution, preparative ultracentrifugation, size exclusion chromatography, field flow fractionation and electrophoresis. However, I was under the impression that the OP anted a cheap method to prepare a solution regardless of keeping the original molecules intact or not, and that is why I suggested meal digestion, and in fact I had prolonged boiling in NaOH for long time as the best known crude and safe method. Some colleagues have reported that using dilute HCl as a primer followed by dilute HNO3 (with molar precise quantities) would shorten digestive dissolution time in hot Conc. NaOH. Link to comment Share on other sites More sharing options...
jdurg Posted June 28, 2005 Share Posted June 28, 2005 Nitric acid will work also, but the product left over is explosive unfortunately, so care must be taken when dissolving this in acetone and in it`s disposal. Actually, plain old nitric acid really won't turn it into an explosive. There's another ingredient that is needed in order to effectively nitrate the cellulouse. I'm not going to be detailing what it is here, but it's fairly important in the nitration reaction. Link to comment Share on other sites More sharing options...
YT2095 Posted June 28, 2005 Share Posted June 28, 2005 well yeah, I didn`t mention that deliberatly, and single base nitration is all that needed too, double base NC wouldn`t be good (although it dissolve in Acetone more readily). Link to comment Share on other sites More sharing options...
H2SO4 Posted June 28, 2005 Share Posted June 28, 2005 sODIUM hYDROXIDE IS OK AT DISSOLVING BIOMATTER (damn caps lock) Link to comment Share on other sites More sharing options...
LKL Posted June 29, 2005 Author Share Posted June 29, 2005 Thanks guys! Yes, the OP was about a cheap/easy method for dissolving the material, enzymes and special ionic liquids aren't readily available at the lab but will remain an option if everything else fails. Indeed, one of the problems my mom encountered was the formation of a gelatinous mixture. However, she did manage to prepare a low-viscosity solution by using HNO3 and NaOH, but it had some undesirable qualities. Using HCl and HNO3 before boiling in NaOH sounds promising and she'll look into it as soon as possible. The task isn't as simple as it may seem since the solution has to be run through U/Po ion exchange resins that might have problems with certain compounds/elements contained in grains of wheat. But that's another story... Link to comment Share on other sites More sharing options...
YT2095 Posted June 29, 2005 Share Posted June 29, 2005 there`s an enzyme contained in salivary amylase (saliva) that will break down much of the starch content, but I don`t think it`ll touch the cellulose, it begins with the letter "P" and I can`t remember it, its only about 5 or 6 letters long anyway, maybe that will help a little too? Link to comment Share on other sites More sharing options...
EL Posted June 30, 2005 Share Posted June 30, 2005 LKL, I forgot to tell you that rinsing the ground flour by acetone followed by rinsing with ethanol, will remove the wheat germ oil from the way, and that you may evaporate those "rinsing agents" to have a concentrated oil extract if the quantity was big enough. Some husk waxes too shall be in that extract. This exposes the cellulose for subsequent operations. The target is to hydrolyse the macro-molecular structure to obtain soluble sugar forms. The function of diluted HCl is found in supramolecular chemistry and it binds ionically at some critical structural bonds and make them vulnerable to hydrolysis. HNO3 denaturises the resident proteins and opens their structures for hydrolysis too. Finally, it is NaOH that does the job. It is absolutely critical that the acidic reactions be applied on already wet meal that was left for at least 24 hours after adding enough distilled water to cover the flour after mixing thoroughly. Gentle heating is recommended over boiling with HCl and HNO3. When Conc. NaOH is applied, better results can be obtained when addition is at room temperature, then after 4 to 6 hours gradual heating up to the boiling temperature is carried out while constantly stirring. In a couple of hours the meal should be syrupy clear with a yellowish tint for partial caramelisation that could not be avoided. Link to comment Share on other sites More sharing options...
Bluenoise Posted June 30, 2005 Share Posted June 30, 2005 there`s an enzyme contained in salivary amylase (saliva) that will break down much of the starch content, but I don`t think it`ll touch the cellulose, it begins with the letter "P" and I can`t remember it, its only about 5 or 6 letters long anyway, maybe that will help a little too? He he salivary amylase isn't saliva. It's the enzyme that you're looking for (aka alpha-amylase). You knew the name of it and didn't even realise it. THis enzyme breaks down starch (amylose) into 5-6 mer chains. This process is followed by an enzyme Hydrolase in the stomac that further degrades it into monomer glucose subunits. Link to comment Share on other sites More sharing options...
weldermanx Posted July 5, 2005 Share Posted July 5, 2005 has anyone ever heard of this stuff this stuff...i forgot what it was called but its like chromium+8 and sulfuric acid that disolves almost anything someone at a hazardous waste dump mentioned it when i was volunteering there Link to comment Share on other sites More sharing options...
weldermanx Posted July 5, 2005 Share Posted July 5, 2005 im pretty sure that would dissolve wheat... im new here if this is just a really random factoid than just ignore me Link to comment Share on other sites More sharing options...
EL Posted July 5, 2005 Share Posted July 5, 2005 You are ignor ..... ed. Link to comment Share on other sites More sharing options...
weldermanx Posted July 7, 2005 Share Posted July 7, 2005 thankyou... yah i just like to talk... type whatever you know how kids are today... they never shut up Link to comment Share on other sites More sharing options...
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