Calmagite

{{Chembox

| Reference = [http://www.sigmaaldrich.com/catalog/ProductDetail.do?N4=C204|ALDRICH&N5=SEARCH_CONCAT_PNO|BRAND_KEY&F=SPEC Calmagite] at Sigma-Aldrich

| ImageFile = Calmagite.png

| ImageName = Skeletal formula

| ImageFile1 = Calmagite-3D-balls-A.png

| ImageSize1 = 220px

| ImageName1 = Ball-and-stick model

| IUPACName = 3-Hydroxy-4-[(2-hydroxy-5-methylphenyl)azo]-1-naphthalenesulfonic acid

|Section1={{Chembox Identifiers

| ChemSpiderID = 21159783

| InChI = 1/C17H14N2O5S/c1-10-6-7-14(20)13(8-10)18-19-17-12-5-3-2-4-11(12)16(9-15(17)21)25(22,23)24/h2-9,20-21H,1H3,(H,22,23,24)

| InChIKey = VBRNLOQCBCPPHL-UHFFFAOYAD

| CASNo = 3147-14-6

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

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 0A3KVV9HZC

| PubChem = 5483111

| SMILES = Oc3ccc(C)cc3N=Nc2c1ccccc1c(cc2O)S(O)(=O)=O

}}

|Section2={{Chembox Properties

| C=17 | H=14 | N=2 | O=5 | S=1

| Appearance = Red to black crystals

| Odor = Phenolic odor

| Density =

| MeltingPtC = 330

| BoilingPt =

| Solubility =

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|Section3={{Chembox Hazards

| MainHazards = May emit ammonia, oxides of sulfur, oxides of nitrogen, and oxides of carbon.

| FlashPt =

| AutoignitionPt =

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Calmagite is a complexometric indicator used in analytical chemistry to identify the presence of metal ions in solution. As with other metal ion indicators calmagite will change color when it is bound to an ion. Calmagite will be wine red when it is bound to a metal ion and may be blue, red, or orange when it is not bound to a metal ion. Calmagite is often used in conjunction with EDTA, a stronger metal binding agent.Harris, Daniel C. Quantitative Chemical Analysis, W.H. Freeman and Company ,2007. {{ISBN|0-7167-7041-5}} This chemical is also used in the quantitation of magnesium in the clinical laboratory.