The buffer solution (di-sodium hydrogen phosphate/potassium dihydrogen phosphate) is gravimetrically prepared using high-quality salts in high-purity water. It is quality controlled and qualified in an ISO/IEC 17025 accredited calibration lab. Its pH value of 7.00 at 20°C is qualified following a 5-point calibration method, using a combined glass electrode, in accordance with DIN 19268, against reference buffer solutions following DIN 19266. 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.

The di-sodium hydrogen phosphate/potassium dihydrogen phosphate buffer solution finds applications in analytical procedures for the calibration, qualification, and monitoring of pH measuring instruments.

• Measured and qualified at an ISO/IEC 17025 and ISO 17034 accredited laboratory
• Traceable to SRMs from NIST and primary certified reference standards from PTB
• Ready-to-use solution available in a sealed bottle and the innovative Titripac^® packaging for positive environmental impact due to reduced waste generation
• Long-lasting with a shelf life of 3 years
• Accompanied with a detailed and batch-specific certificate of analysis (CoA) for an effective audit

CERTIPUR is a registered trademark of Merck KGaA, Darmstadt, Germany

Titripac is a registered trademark of Merck KGaA, Darmstadt, Germany