Buffer solutions

General description
It includes a pack of three certified buffer solutions, gravimetrically prepared using high-quality reagents and water at a registered calibration laboratory. Their pH values of 4.01 (phthalate), 7.00 (phosphate), and 9.00 (borate) at 25°C are measured using combined glass electrode as per the 5-point calibration method. The measurements are made following DIN 19268 using reference buffer solutions compliant to DIN 19266, NIST, IUPAC, Ph. Eur, and USP. The pH of buffers is strongly dependent on the temperature and therefore a constant temperature must be maintained during their use.
Please visit ISO certificates and Site Quality Self-Assessments to access the current certificates of accreditation.
Download your certificate at http://www.sigma-aldrich.com to view certified values, including uncertainty and expiry date.
Application
They are used as standards to calibrate pH measuring instruments or pH electrodes and as controls to measure the pH of other solutions.
Features and Benefits
Measured and qualified at an ISO/IEC 17025 and ISO 17034 accredited laboratory
Traceable to secondary reference standards from NIST and primary certified reference standards from PTB
Ready-to-use solutions available in 30 mL sachets
Accompanied with a detailed and batch-specific certificate of analysis (CoA) for an effective audit
Product label follows the ISO Guide 31 and contains information about ordering number, article description, lot number, safety data, and expiry date
Packaging material subjected to comprehensive stability studies as per ISO Guide 35
pH 4.00 and pH 6.99 buffer CRMs in the pack are accurate upto +/- 0.02 at 25 °C and the pH 9.00 buffer CRM is accurate upto +/-0.03 at 25 °C
Legal Information
CERTIPUR is a registered trademark of Merck KGaA, Darmstadt, Germany