Lactose Standard 5 %

solid water standard for coulometric/volumetric Karl Fischer Titration and Karl Fischer oven method Aquastar®

Milk sugar, Lactobiose, Lactose Standard 5 %
Empirical Formula (Hill Notation):
C12H22O11 · xH2O
CAS Number:
Molecular Weight:
342.30 (anhydrous basis)
EC Index Number:

storage conditions

Store at +15°C to +25°C.

Quality Level


ISO 17025, 17034

product line




autoignition temp.

390 °C


>10000 mg/kg LD50, oral (Rat)


Karl-Fischer titration: suitable
titration: suitable


4.0-6.5 (20 °C, 100 g/L in H2O)


202 °C

bulk density

500 kg/m3

storage temp.


General description

The lactose standard 5% is solid standard, prepared gravimetrically from high-purity reagents. It is analyzed in an ISO/IEC 17025 and ISO guide 34 accredited calibration laboratory. Its water content of 5% is measured by the coulometric Karl Fischer oven method at 150°C with an extraction time of 300 seconds, in accordance with ISO 760.


Lactose standard 5% is used as a certified reference material (CRM) for both the coulometric and volumetric Karl Fischer water determinations, with or without the Karl Fischer oven. It is particularly suitable when the working medium used consists of solvents mixtures in which sodium tartrate dihydrate is slightly soluble. And it is used as an oven standard in the preferred temperature range of 140°C -190°C.

Features and Benefits

  • Available in a secure plastic bottle with the material subjected to stability and homogeneity studies, following ISO 17034 and ISO Guide 35
  • High-quality offering accurate and reliable results
  • Accompanied with a comprehensive and batch-specific certificate of analysis (CoA) for an effective quality management system
  • Measured and qualified in an ISO/IEC 17025 and ISO 17034 accredited laboratory


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


Replaces: 1.12939.0010

Analysis Note

Water content: 5.00 - 5.20 %
Measurement method: coulometric according Karl Fischer
extended measuring uncertainly: +/- 0.05 %

Legal Information

AQUASTAR is a registered trademark of Merck KGaA, Darmstadt, Germany
SmartChemicals enable wireless transfer of CoA data stored on an RFID tag on the consumable bottle to the titrator, reducing effort and chance for human error. Crucial data required for the application is transmitted safely, reliably and intelligently to the instrument.
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