we are studying the production of mannitol by lactobacillus and we have to determine manitol yeild ,we have some proplems with clorometric method ,there is no yellow color appeare ,i need the protocols of this method and a ,ready standard curve with low concetrations ie; 25 ,50 100,150 nmol
Dear Sir. Concerning your issue about the chemical method for determination of mannitol. There are two types of method for determination of mannitol concentration. One of them depend on the reduction of ferricyanide by mannitol in strongly alkaline solution requires correction of glucose content of the sample. The other disposes glucose by treatment with yeast. Also cab determined spectrophotometrically by enzymatic method. The following below links may help you in your analysis:
http://www.jbc.org/content/170/1/165.full.pdf
http://edoc.hu-berlin.de/oa/degruyter/cclm.1981.19.3.139.pdf
http://www.fao.org/ag/agn/jecfa-additives/specs/Monograph1/Additive-275.pdf
Thanks
Thin-layer chromatography (2.2.27).
Test solution Dissolve 25 mg of the substance to be examined in water R and dilute to 10 mL with the same solvent.
Reference solution (a) Dissolve 25 mg of mannitol CRS in water R and dilute to 10 mL with the same solvent.
Reference solution (b) Dissolve 25 mg of mannitol R and 25 mg of sorbitol R in water R and dilute to 10 mL with the same solvent.
Plate TLC silica gel plate R.
Mobile phase water R, ethyl acetate R, propanol R (10:20:70 V/V/V).
Application 2 µL.
Development Over 2/3 of the plate.
Drying In air.
Detection Spray with 4-aminobenzoic acid solution R and dry in a current of cold air until the acetone is removed; heat at 100 °C for 15 min, allow to cool then spray with a 2 g/L solution of sodium periodate R; dry in a current of cold air and heat at 100 °C for 15 min.
System suitability: reference solution (b): — the chromatogram shows 2 clearly separated spots.
Results The principal spot in the chromatogram obtained with the test solution is similar in position, colour and size to the principal spot in the chromatogram obtained with reference solution (a).◊
Maybe it can be done this way: Biochemical Engineering Journal 42(1):77-83 · October 2008, DOI: 10.1016/j.bej.2008.05.020
It is not specific but it worked in culture medium for sorbitol and glycerin if the concentration is high against other substances.
Good luck
