Bucci et. al. show that bitrex, can be identified using UV-vis spectrophotometry by reaction with disulphine blue VN-150, with which it forms an intensely colored complex that is easily extracted into chloroform, see link.

http://www.sciencedirect.com/science/article/pii/S0039914005003292

Thanks Bruce..

can any other method too.

For an HPLC method for Bitrex see the attached link.

Article Determination of Bitrex, Quassia Powder and Sucrose Octaacet...

Dear Sir. Concerning your issue about how to determine BITREX in ethanol. BITREX  can be determined by different methods such as tandem technique, mass spectroscopy with atmospheric-pressure chemical ionization (APCI-MS) coupled with direct flow injection,  or  can be determined by  dissolving it in glacial acetic acid and addition of Mercuric acetate solution and then titrated with perchloric acid in the presence of crystal violet . For more details see the following below links which may help you in your analysis:

http://onlinelibrary.wiley.com/doi/10.1002/jhrc.1240200605/abstract

http://www.forensicscience.pl/pfs/63_buszewicz.pdf

https://law.resource.org/pub/in/bis/S11/is.4117.2008.pdf

Thanks

Thanks Mr Isam Eldin.