Nitrazine Yellow

Other Names Nitrazine yellow C.1.14890 Delta Paper Nitrazol Yellow 

CA Index Name 2,7-Naphthalenedisulfomc acid, 3-[(2,4-dmitrophenyl)azo]-4-hydroxy-, disodium salt 

Chemical/Dye Class Azo Molecular Formula Ci6H8N40nS2Na2 Molecular Weight 542.37 pH Range 6.0-7.2 

Color Change at pH Bright yellow (6.0) to bright blue (7.2) 

Physical Form Red-brown powder Solubility Soluble in water, acetic acid ethanol UV-Visible (A, ,ax) 586 nm Melting Point 250°C Synthesis Synthetic methodsi-  

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Nitrazine Yellow (C.I. 14 890) [5423-07-4] brownish yellow-blue-violet 0.05 (in 70% ethanol)... 

Add CaCl2 solution (equal in volume to that of the solution) and allow to stand for several minutes. A white precipitate indicates fluoride, oxalate, phosphate, arsenate, and tartrate t a precipitate which separates on boiling for 1-2 minutes is citrate. Of these only oxalate and fluoride are insoluble in dilute acetic acid. Hence extract the white precipitate with dilute acetic acid and filter. A residue (R) insoluble in dilute acetic acid, indicates oxalate and/or fluoride. Exactly neutralize the acetic acid solution by adding sodium hydroxide solution from a dropper and testing with an indicator paper or solution (bromothymol blue or nitrazine yellow is suitable) a white precipitate indicates the presence of phosphate, arsenate, and/or tartrate. The precipitate often separates slowly. Add a little silver nitrate solution to the suspension or solution a yellow precipitate indicates the presence of phosphate a brownish-red precipitate indicates arsenate or arsenate plus phosphate. 

The introduction of 1 drop of nitrazine yellow indicator into the solution is to be preferred. (This indicator covers the pH range 5-5-72 and the colour change is from yellow to blue.) The addition of NaOH solution is continued until the solution just assumes a pale-blue colour. 

Nitrazine yellow (0-1 %). Dissolve 0-1 g of nitrazine yellow (2,4-dinitro-benzeneazo)-l-naphthol-4,8-disulphonic acid, disodium salt, (Colour Index 14890) in 100 ml water. 

Zhang, Y. Deng, R Liu, G. Determination of nitrazine yellow by high performance liquid chromatography. Huaxue Shiji 1997,19, 95-97 Chem. Abstr. 1997,127, 96558. 

Zhang, Y. Synthetic technology of nitrazine yellow. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1110696,1995 Chem. Abstr. 1996,124, 263380. 

Van der Schueren L, De Meyer T, Steyaert 1, Ceyltm O, Hemelsoet K, Van Speybroeck V, De Clerck K (2013) Polycaprolactone and polycaprolactone/chitosan ntmofibres functionalised with the pH-sensitive dye Nitrazine Yellow. Caibohyd Polym 91(l) 284-293. doi 10.1016/j.caibpol.2012.08.003... 

Acid dye. Strictly, the name Nitrazine yellow refers to the disodium salt. 

Nipagin A, in H-00113 >Nipagin M, in H-00113 Nitchromazo, see D-00558 o-Nitral green, N-00072 p-Nitral green, N-00073 Nitrazine yellow, see D-00965 Nitrazol yellow, see D-00965 5,5 -Nitrilodibarbituric acid, see P-00281... 

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