Nitrazine

Quality 0.50 · 1 view · Updated 2 months ago

title: "Nitrazine" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["stool-tests", "ph-indicators", "nitrobenzene-derivatives", "naphthalenesulfonic-acids", "anilines", "obstetric-drugs", "obstetrics"] topic_path: "general/stool-tests" source: "https://en.wikipedia.org/wiki/Nitrazine" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::callout[type=note] phenapthazine, a pH indicator dye ::

| verifiedrevid = 421100991 | ImageFile=Nitrazine.png | ImageSize=200px | ImageFile1=Nitrazine ball-and-stick.png | IUPACName=(3E)-3-[(2,4-Dinitrophenyl)hydrazono]-4-oxonaphthalene-2,7-disulfonic acid | OtherNames=Nitrazine yellow; Phenaphthazine |Section1={{Chembox Identifiers | ChemSpiderID_Ref = | ChemSpiderID = 5288340 | 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- | InChIKey = IHRSXGONVFFQQF-SDXDJHTJBN | StdInChI_Ref = | StdInChI = 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- | StdInChIKey_Ref = | StdInChIKey = IHRSXGONVFFQQF-SDXDJHTJSA-N | CASNo_Ref = | CASNo = 1716-22-9 | CASNo1_Ref = | CASNo1 = 5423-07-4 | CASNo1_Comment = (disodium) | UNII_Ref = | UNII = USH6E4Z2F7 | UNII1_Ref = | UNII1 = 4U1WVN6KUX | UNII1_Comment = (disodium) | PubChem=6911856 | SMILES = [O-]N+c1ccc(c(N+=O)c1)N/N=C3/C(=C\c2c(ccc(c2)S(=O)(=O)O)C3=O)S(=O)(=O)O |Section2={{Chembox Properties | Formula=C16H10N4O11S2 | MolarMass=498.40 g/mol | Appearance= | Density= | MeltingPt= | BoilingPt= | Solubility= |Section3={{Chembox Hazards | MainHazards= | FlashPt= | AutoignitionPt =

Nitrazine or phenaphthazine is a pH indicator dye often used in medicine. More sensitive than litmus, nitrazine indicates pH in the range of 4.5 to 7.5. Nitrazine is usually used as the disodium salt.

Use

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 a fecal pH test for diagnosing intestinal infections or other digestive problems
In civil engineering, to determine the carbonatation spread in concrete structures and therefore assess the state of the rebar's passivation film.

References

"Point-of-Care Testing, Fecal pH Measurement".

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::