Patent Blue V: Difference between revisions

| CASNo_Ref = {{cascite|correct|CAS}}

| ChEBI = 59601

| EC_numberEINECS = 243-654-4

| EINECSEC_number1 = 222-573-8

| KEGGKEGG1 = D11704

| PubChem = 77074

'''Patent Blue V''', also called '''Food Blue 5''', '''Sulphan Blue''', Acid Blue 3, L-Blau 3, C-Blau 20, Patentblau V, Sky Blue, or C.I. 42051 and, is a darksky bluishblue synthetic [[triphenylmethane dye]] used as a [[food coloring]].<ref name=Ull>{{Ullmann's | last1 = Gessner | first1 = Thomas | last2 = Mayer | first2 = Udo | title = Triarylmethane and Diarylmethane Dyes | year = 2000 | doi = 10.1002/14356007.a27_179}}</ref> As a [[food additive]], it has [[E number]] '''E131'''. It is a sodium or calcium salt of [4-(α-(4-diethylaminophenyl)-5-hydroxy- 2,4-disulfophenylmethylidene)-2,5-cyclohexadien-1-ylidene] diethylammonium hydroxide [[inner salt]].

It is not widely used, but in Europe it can be found in [[Scotch egg]]s,{{cn|date=November 2017}} certain [[Gummiesgummies|jelly sweets]], [[Curaçao (liqueur)|blue Curaçao]], certain [[jellogelatin dessert]] varieties (though not in actual Jell-O brand products)s, among others. An important advantage is the very deep color it produces even at low concentration, a disadvantage is that it fades fairly quickly when exposed to light.

In medicine, Patent Blue V is used in [[lymphangiography]] and [[sentinel node biopsy]] as a dye to color [[lymph vessel]]s.<ref>[http://jnm.snmjournals.org/cgi/content/full/44/4/649 Erratum - 44 (4): 649 - The Journal of Nuclear Medicine<!-- Bot generated title -->]</ref> <!--Though there is lot of ambiguity of the name patent blue v and it is different than food blue 5.-->{{clarify|date=January 2014}} It is also used in dental [[disclosing tablets]] as a stain to show [[dental plaque]] on teeth.

conditions. It is useful as a [[pH indicator]] for the range 0.8–3.0.<ref>{{cite book |title= Handbook of Acid–Base Indicators |url= https://archive.org/details/handbookacidbase00sabn |url-access= limited |first= R. W. |last= Sabnis |publisher= CRC Press |year= 2008 |pages= 295–297[https://archive.org/details/handbookacidbase00sabn/page/n311 295]–297 |chapter= Patent Blue V |isbn= 9780849382185 }}</ref> The structure is also [[redox]]-sensitive, changing from a reduced yellow form to an oxidized red form in solution. The [[reduction potential]] of around 0.77&nbsp;[[volt]]s is similar to that of other triphenylmethane dyes. It is usable as a [[Reversible reaction|reversible]] redox indicator in some analytical methods.<ref>{{cite journal |title= Patent blue V as a pH and redox indicator |first1= John H. |last1= Yoe |first2= George R. |last2= Boyd |journal= Ind. Eng. Chem. Anal. Ed. |year= 1939 |volume= 11 |issue= 9 |pages= 492–493 |doi= 10.1021/ac50137a008 }}</ref>

Patent Blue V is banned as a [[food dye]] in [[Australia]] and [[US]], because health officials in these countries suspect that it may cause allergic reactions, with symptoms ranging from itching<ref name=Barthelmes2010>L. Barthelmes, A. Goyal, R.G. Newcombe, F. McNeill, R.E. Mansel, [http://dx.doi.org/10.1016/j.ejso.2009.10.007 Adverse reactions to patent blue V dye – The NEW START and ALMANAC experience], European Journal of Surgical Oncology (EJSO), Volume 36, Issue 4, April 2010, Pages 399-403, ISSN 0748-7983[[doi:10.1016/j.ejso.2009.10.007]].</ref> and [[nettle rash]] to [[nausea]], [[hypotension]], and in rare cases [[anaphylactic shock]]; it is therefore not recommended for children in those countries for children.