{"product_id":"starch-indicator-soln-1-1-gl-zs0940-128","title":"Starch Indicator Solution 1%, 1 Gallon","description":"\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhat it is.\u003c\/strong\u003e This starch indicator is a 1% aqueous starch solution, supplied in a 1 gallon size. It is the standard endpoint indicator for iodometric and iodimetric titrations, forming an intense blue-black color with iodine.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHow it works.\u003c\/strong\u003e The amylose fraction of starch forms a helical structure that traps triiodide ions, producing a deep blue-black complex visible at extremely low iodine concentrations. When the last iodine is reduced by thiosulfate, the color disappears sharply, marking the endpoint.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhen to add it.\u003c\/strong\u003e In iodometric titrations, add starch near the endpoint, when the yellow iodine color has faded to pale straw. Adding it too early, at high iodine concentration, can bind iodine tightly and slow its release, blurring the endpoint.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIodimetric titrations.\u003c\/strong\u003e In iodimetry, where standard iodine is the titrant, starch is added at the start, and the endpoint is the first permanent blue color. Ascorbic acid, sulfite, and arsenite are classic analytes for this approach.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSensitivity.\u003c\/strong\u003e Starch makes iodine visible at concentrations far below what its yellow color alone reveals, which is why it improves accuracy in dilute titrations such as residual chlorine and dissolved oxygen.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReady-made convenience.\u003c\/strong\u003e Preparing starch indicator requires dispersing soluble starch in boiling water and cooling it, and homemade solutions spoil quickly. A ready-made 1% solution saves preparation time and gives consistent sensitivity.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStability.\u003c\/strong\u003e Starch solutions support microbial growth and slowly lose sensitivity. Keep the container closed, avoid contamination, and replace solution that becomes moldy, cloudy, or gives a reddish or brown color instead of blue.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThe iodometric system.\u003c\/strong\u003e Use starch with Lab Pro's Sodium Thiosulfate 0.1 N Solution, 1 Gallon and Potassium Iodide 10% (w\/v) Solution, 1 Quart for complete iodometric determinations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAlternative endpoint detection.\u003c\/strong\u003e For colored or turbid samples where the starch color is hard to see, potentiometric endpoint detection with a platinum electrode offers an alternative. Starch remains the simplest and most widely used visual indicator.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWhere it is used.\u003c\/strong\u003e Starch indicator is used in water and wastewater testing for chlorine and dissolved oxygen, in food labs for peroxide value and vitamin C, in bleach and disinfectant QC, and in teaching labs demonstrating redox titrations.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003ctable style=\"width:100%; border-collapse:collapse; border:1px solid #cfcfcf; margin-bottom:28px;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eProduct\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003eStarch indicator solution\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eConcentration\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003e1% starch\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eActive Component\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003eSoluble starch (amylose forms the iodine complex)\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eCAS Numbers\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003e9005-84-9 (soluble starch); 7732-18-5 (water).\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eEndpoint Color\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003eBlue-black with iodine; colorless when iodine is consumed\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eWhen to Add (iodometry)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003eNear the endpoint (pale yellow stage)\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eWhen to Add (iodimetry)\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003eAt the start of the titration\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eTypical Dose\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003eAbout 1 to 2 mL per titration\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eAppearance\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003eColorless to slightly opalescent liquid\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003eStability Note\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003eSupports microbial growth; replace if cloudy or moldy\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left; width:32%; background:#f5f5f5;\"\u003e\u003cstrong\u003ePackage Size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd style=\"border:1px solid #cfcfcf; padding:8px 12px; vertical-align:top; text-align:left;\"\u003e\u003cstrong\u003e1 gallon\u003c\/strong\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch4\u003eApplications \/ Common Uses\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIodometric endpoints:\u003c\/strong\u003e Signals iodine consumption in thiosulfate titrations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIodimetric titrations:\u003c\/strong\u003e Shows the first excess of standard iodine.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChlorine and oxygen testing:\u003c\/strong\u003e Improves endpoint detection in dilute samples.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVitamin C analysis:\u003c\/strong\u003e Indicates iodimetric ascorbic acid titrations.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTeaching labs:\u003c\/strong\u003e Demonstrates the starch-iodine reaction.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eStorage, Handling \u0026amp; Shipping\u003c\/h4\u003e\n\u003cp\u003eStore tightly closed at room temperature or as directed on the label, away from contamination. Starch solutions can support microbial growth, so dispense with clean tools and replace solution that becomes cloudy, moldy, or gives a weak or reddish color with iodine.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncompatible materials:\u003c\/strong\u003e Strong oxidizers.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePersonal protection:\u003c\/strong\u003e Standard laboratory gloves and eye protection.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpill response:\u003c\/strong\u003e Wipe up and rinse the area with water.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFirst aid:\u003c\/strong\u003e Eyes: rinse with water if irritation occurs.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eRelated Categories \u0026amp; Services\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eShop \u003ca href=\"https:\/\/labproinc.com\/pages\/buffers-standards-solutions\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eBuffers, Standards \u0026amp; Solutions\u003c\/a\u003e for related products in this category.\u003c\/li\u003e\n\u003cli\u003eExplore \u003ca href=\"https:\/\/labproinc.com\/collections\/general-chemistry\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eGeneral Chemistry\u003c\/a\u003e and \u003ca href=\"https:\/\/labproinc.com\/collections\/acs-grade-laboratory-chemicals\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eACS Grade Laboratory Chemicals\u003c\/a\u003e.\u003c\/li\u003e\n\u003cli\u003e\n\u003ca href=\"https:\/\/labproinc.com\/pages\/be-a-lab-pro-vmi-program\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eVendor Managed Inventory (VMI) Program\u003c\/a\u003e: Lab Pro can stock, track, and replenish this item on site so it never runs out. Contact info@labproinc.com or 888-452-2776 to set up a VMI assessment.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eRelated Articles\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/labproinc.com\/blogs\/news\/quantitative-analysis\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eTitration Methods for Precise Chemical Analysis in Labs\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/labproinc.com\/blogs\/chemicals-and-solvents\/ranking-oxidizing-agents-strongest-to-weakest-which-is-best-for-which-tasks\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eRanking Oxidizing Agents Strongest to Weakest: Which is Best For Which Tasks?\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"https:\/\/labproinc.com\/blogs\/chemicals-and-solvents\/the-importance-of-deionized-water-in-laboratory-applications\" target=\"_blank\" rel=\"noopener noreferrer\"\u003eThe Importance of Deionized Water in Laboratory Applications\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Lab Pro Inc","offers":[{"title":"Default Title","offer_id":47266339127445,"sku":"ZS0940-128","price":60.2,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0757\/2327\/6437\/files\/MainImage_fec13c26-2528-43b1-86ca-b5780b0d1e35.png?v=1791914407","url":"https:\/\/labproinc2.myshopify.com\/products\/starch-indicator-soln-1-1-gl-zs0940-128","provider":"Lab Pro Inc Plus","version":"1.0","type":"link"}