{"product_id":"horiba-ion-standard-solutions","title":"Horiba Ion Standard Solutions","description":"\u003cp\u003eGenuine HORIBA ion standard solutions for calibrating ion-selective electrodes on LAQUA handheld and benchtop meters. Each 500 mL bottle is supplied at a certified concentration so you can build a two-point calibration across the range you actually measure.\u003c\/p\u003e\n\n\u003cp\u003eEvery ion is available in two strengths — \u003cstrong\u003e1000 mg\/L\u003c\/strong\u003e (suffix SH, high) and \u003cstrong\u003e100 mg\/L\u003c\/strong\u003e (suffix SL, low). Ion-selective electrodes respond logarithmically to concentration, so calibrating at two points a decade apart is what establishes the slope of that response. A single-point calibration only sets an offset and will give increasingly wrong answers the further your sample sits from that one point.\u003c\/p\u003e\n\n\u003ch3\u003eAvailable ions\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eAmmonium\u003c\/strong\u003e (NH₄⁺) — 1000 and 100 mg\/L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCalcium\u003c\/strong\u003e (Ca²⁺) — 1000 and 100 mg\/L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChloride\u003c\/strong\u003e (Cl⁻) — 1000 and 100 mg\/L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFluoride\u003c\/strong\u003e (F⁻) — 1000 and 100 mg\/L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNitrate\u003c\/strong\u003e (NO₃⁻) — 1000 and 100 mg\/L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePotassium\u003c\/strong\u003e (K⁺) — 1000 and 100 mg\/L\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSodium\u003c\/strong\u003e (Na⁺) — 1000 and 100 mg\/L\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eBracket your samples\u003c\/h3\u003e\n\u003cp\u003eChoose the pair of standards that spans your expected sample concentrations. If your samples typically fall between 5 and 50 mg\/L, calibrate with the 100 mg\/L standard and a dilution of it rather than with the 1000 mg\/L standard — extrapolating well below the calibrated range is where ISE measurements most often go wrong. Prepare dilutions with deionized water and use them the same day.\u003c\/p\u003e\n\n\u003ch3\u003eUse an ionic strength adjustor\u003c\/h3\u003e\n\u003cp\u003eAn ISE responds to ion \u003cem\u003eactivity\u003c\/em\u003e, not total concentration, and activity depends on the ionic strength of the solution. Adding the matching ionic strength adjustor (ISA, or TISAB for fluoride) to both your standards and your samples in equal proportion brings them to a common ionic strength so the comparison is valid. Skipping this step is the most common cause of ISE results that look plausible but read consistently low. Adjustors are listed separately.\u003c\/p\u003e\n\n\u003ch3\u003eApplications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eNutrient monitoring — nitrate and ammonium in surface water, groundwater and effluent\u003c\/li\u003e\n\u003cli\u003eDrinking water fluoride compliance monitoring\u003c\/li\u003e\n\u003cli\u003eChloride determination in water, brines and process streams\u003c\/li\u003e\n\u003cli\u003eCalcium and hardness-related measurements in treatment and boiler water\u003c\/li\u003e\n\u003cli\u003eSodium monitoring in high-purity water, boiler feed and condensate\u003c\/li\u003e\n\u003cli\u003ePotassium and nutrient analysis in agriculture, soil extracts and hydroponics\u003c\/li\u003e\n\u003cli\u003eRoutine ISE verification under a laboratory quality system\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eRelated items\u003c\/h3\u003e\n\u003cp\u003eIon-selective electrode kits, replacement ISE cartridges and membranes, ionic strength adjustors and ISE filling solutions are all stocked — see the \u003ca href=\"https:\/\/envirotechonline.com\/collections\/horiba-parts-accessories\"\u003eHoriba Parts \u0026amp; Accessories\u003c\/a\u003e collection.\u003c\/p\u003e\n\n\u003cp\u003eBrowse all \u003ca href=\"https:\/\/envirotechonline.com\/collections\/horiba\"\u003eHORIBA instruments\u003c\/a\u003e.\u003c\/p\u003e","brand":"Horiba","offers":[{"title":"500-NH4-SH - Ammonium Ion Standard, 1000 mg\/L, 500 mL - 3200697171","offer_id":48226471084222,"sku":"3200697171","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-NH4-SL - Ammonium Ion Standard, 100 mg\/L, 500 mL - 3200697172","offer_id":48226471116990,"sku":"3200697172","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-CA-SH - Calcium Ion Standard, 1000 mg\/L, 500 mL - 3200697175","offer_id":48226471149758,"sku":"3200697175","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-CA-SL - Calcium Ion Standard, 100 mg\/L, 500 mL - 3200697176","offer_id":48226471182526,"sku":"3200697176","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-CL-SH - Chloride Ion Standard, 1000 mg\/L, 500 mL - 3200697167","offer_id":48226471215294,"sku":"3200697167","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-CL-SL - Chloride Ion Standard, 100 mg\/L, 500 mL - 3200697168","offer_id":48226471248062,"sku":"3200697168","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-F-SH - Fluoride Ion Standard, 1000 mg\/L, 500 mL - 3200697163","offer_id":48226471280830,"sku":"3200697163","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-F-SL - Fluoride Ion Standard, 100 mg\/L, 500 mL - 3200697164","offer_id":48226471313598,"sku":"3200697164","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-NO3-SH - Nitrate Ion Standard, 1000 mg\/L, 500 mL - 3200697179","offer_id":48226471346366,"sku":"3200697179","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-NO3-SL - Nitrate Ion Standard, 100 mg\/L, 500 mL - 3200697180","offer_id":48226471379134,"sku":"3200697180","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-K-SH - Potassium Ion Standard, 1000 mg\/L, 500 mL - 3200697183","offer_id":48226471411902,"sku":"3200697183","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-K-SL - Potassium Ion Standard, 100 mg\/L, 500 mL - 3200697184","offer_id":48226471444670,"sku":"3200697184","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-NA-SH - Sodium Ion Standard, 1000 mg\/L, 500 mL - 3200987463","offer_id":48226471477438,"sku":"3200987463","price":92.0,"currency_code":"USD","in_stock":true},{"title":"500-NA-SL - Sodium Ion Standard, 100 mg\/L, 500 mL - 3200987464","offer_id":48226471510206,"sku":"3200987464","price":92.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0592\/9926\/6750\/files\/csm_1000_mg_L_Potassium_Ion_Standard_Solution_a30478e792.png?v=1785337209","url":"https:\/\/envirotechonline.com\/products\/horiba-ion-standard-solutions","provider":"EnviroTech Services","version":"1.0","type":"link"}