Dear Greeta:

Here is a most reliable and most inexpensive TEST:

D-Mannose has a slightly SWEET taste (and it is used as sweetener in soft drinks.

By contrast:  Chitosan - has NO Taste at all .   

My very Best Regards to you,     Leonid

Another very reliable and very inexpensive test:

Chitosan - is insoluble in water, while Mannose - is well soluble.

Leonid

Thank you very much Sir 

Here is an easier method of synthesis of Man-Chitosan:

A new and practical laboratory approach to synthesize mannose modified chitosan (Man-chitosan) was developed via reductive amination reaction. Chitosan and mannose were used as raw materials. The reaction condition was mild and controllable. The overall yield was 47–52%. Each reaction products and Man-chitosan were characterized by 1H NMR, ESI-MS, FT-IR and TGA spectrum. FT-IR and 1H NMR results showed that mannose conjugated to chitosan via an alkane chain bridge (single bondCH2single bondCH2single bond). The degree of substitution was calculated by element analysis.

http://www.sciencedirect.com/science/article/pii/S0141813011004363

As to confirmation for the product obtained - I guess is the FTIR method, though you for some reason do not like it. BUT an appearance of any additional peak in the region 1100-1000cm-1 - will confirm the formation of your product. I realize that this region of IR-spectrum of polysaccarides is overcrowded by IR-bands, but ANY change, e.g. formation of shoulder, assymmetry of any band will speak in favor of Man-Chit formation.  Do not be too choosy.

Best Regards,   Leonid

Hello Sir 

I m highly thankful to you. it will definitely help me.

With regard, Geeta Arya 

Hello Leonid Sir 

I need your kind help, Sir. I m following a paper which have very simple and basic method for chitosan modification with mannose. I m also sending you a link of that paper. Sir but I m facing problems because e detailed protocol is not given. Sir can it is possible to do FTIR, with aqueous samples.

Article Mannose-conjugated chitosan nanoparticles loaded with rifamp...

As you know - water has only 3 main bands in IR-spectrum: appr. 3400 O-H stretching;

appr. 1640 H-O-H deformation (scissoring) and a broad much lower intensity band of out-of-plane deformation of O-H. Since the main changes due to your reaction are expected in the region of pyranose ring: stretching of C-O and C-O(H) bands in the region 1180-1020cm-1 [there are many peaks in this region and many of them are overlapped - to form an "envelope of bands" with several peaks and several shoulders] -----> this region of spectrum is NOT masked by water absobance bands !!!

So you can easily use this region as "analytical".  However some smooth , of low intensity background from distantly positioned bands of water - will give a very small contribution even in the region 1200-1000cm-1. 

That is why anyway it will be better to subtract the spectrum of neat water.

Also - as follows from my own experience - the most reliable and reproducible results you  wll get if the concentration of solute will be higher than 10%.

Good Luck,                           Leonid

thank u sir 

Sir, in the paper I attached, dialysis was performed after modification. what is the reason for the same.

I think dialysis was needed - for to separate the drug-product from ionic components

(salts, Na+...etc.) but I am rather spectroscopist than organic chemist. Sorry, can not give with surety an explanation about dialysis.

Leonid

Thank u sir for answering my queries.

Hello Leonid Sir

Can I use ninhydrin method to check whether my chitosan is modified or not if yes sir kindly provide me some information regarding the same