Nitrazine

Nitrazine

Names
IUPAC name (3E)-3-[(2,4-Dinitrophenyl)hydrazono]-4-oxonaphthalene-2,7-disulfonic acid
Other names Nitrazine yellow; Phenaphthazine
Identifiers
CAS Number	1716-22-9Y 5423-07-4(disodium)Y[CAS]
3D model (JSmol)	Interactive image
ChemSpider	5288340Y
PubChemCID	6911856
UNII	USH6E4Z2F7Y 4U1WVN6KUX(disodium)Y
InChI InChI=1S/C16H10N4O11S2/c21-16-11-3-2-10(32(26,27)28)5-8(11)6-14(33(29,30)31)15(16)18-17-12-4-1-9(19(22)23)7-13(12)20(24)25/h1-7,17H,(H,26,27,28)(H,29,30,31)/b18-15-Y Key: IHRSXGONVFFQQF-SDXDJHTJSA-NY InChI=1/C16H10N4O11S2/c21-16-11-3-2-10(32(26,27)28)5-8(11)6-14(33(29,30)31)15(16)18-17-12-4-1-9(19(22)23)7-13(12)20(24)25/h1-7,17H,(H,26,27,28)(H,29,30,31)/b18-15- Key: IHRSXGONVFFQQF-SDXDJHTJBN
SMILES [O-][N+](=O)c1ccc(c([N+]([O-])=O)c1)N/N=C3/C(=C\c2c(ccc(c2)S(=O)(=O)O)C3=O)S(=O)(=O)O
Properties
Chemical formula	C16H10N4O11S2
Molar mass	498.40 g/mol
Except where otherwise noted, data are given for materials in theirstandard state(at 25 °C [77 °F], 100 kPa). Yverify(what isYN?) Infobox references

Nitrazineorphenaphthazineis apH indicatordye often used inmedicine.More sensitive thanlitmus,nitrazine indicates pH in the range of 4.5 to 7.5. Nitrazine is usually used as the disodium salt.

Use

Nitrazine(pH indicator)
below pH 4.5		above pH 7.5
4.5	⇌	7.5

• This test is done to ascertain the nature of fluid in the vagina during pregnancy especially when premature rupture of membranes (PROM) is suspect. This test involves putting a drop of fluid obtained from the vagina onto paper strips containing nitrazine dye. The strips change color depending on the pH of the fluid. The strips will turn blue if the pH is greater than 6.0. A blue strip means it's more likely the membranes have ruptured.

This test, however, can produce false positives. If blood gets in the sample or if there is an infection present, the pH of the vaginal fluid may be higher than normal. Semen also has a higher pH, so recent vaginal intercourse can produce a false reading.

• To perform afecal pH testfor diagnosing intestinal infections or other digestive problems
• Incivil engineering,to determine thecarbonatationspread inconcretestructures and therefore assess the state of therebar'spassivationfilm.