It is a solid standard prepared gravimetrically from high-purity potassium sulfate and sodium tungsten dihydrate. The water content of it is determined by coulometric Karl Fischer oven method at 170°C with an extraction time of 600 seconds following ISO 760. Additionally, its measured water content is verified by thermogravimetric analysis. Unlike other solid standards such as tartrate, lactose, or citrate, the water standard oven 1% has significantly lower water content and can be used over a broad temperature range of 150°C to 400°C due to its inorganic composition. It is characterized in accredited quality control (QC) laboratory according to DIN EN ISO/IEC 17025.
Water standard oven 1% is used as certified reference material to check the accuracy of coulometric and volumetric water determinations, according to ISO 9001 chapter 7.1.5 “Monitoring and measuring resources”, using Karl Fischer oven and thermobalances. But its low water content of 1% makes it particularly suitable for water determinations using Karl Fischer oven with a coulometer.
Features and Benefits
- Packed in convenient glass bottles with the material subjected to stability and homogeneity studies following ISO 17034 and ISO Guide 35
- Supplied with a batch-specific certificate of analysis (CoA) having data on exact measured water, uncertainty, method of analysis, measuring method, and minimum shelf life
- Characterized in an ISO/IEC 17025 and ISO 17034 accredited calibration laboratory
- Directly traceable to SI unit (kg)
SKU-pack size numbers ending with a "3" are SmartChemicals with an RFID tag on the label for seamless data transfer to the instrument, e.g. xxxxxx1003 or xxxxxxx 4003. More information on www.sigmaaldrich.com/SmartChemicals
AQUASTAR is a registered trademark of Merck KGaA, Darmstadt, Germany