Merck, 1.09461.1000, Buffer solution

The boric acid/potassium chloride/sodium hydroxide certified buffer solution is gravimetrically prepared using high-quality reagents as per DIN EN ISO/IEC 17025. Its pH value of 9.00 at 20°C is measured following a 5-point calibration method, using a combined glass electrode. The measurement is made following DIN 19268 using reference buffer solutions compliant to DIN 19266, NIST, IUPAC, Ph. Eur, and USP. Its pH value is strongly dependent on the temperature and therefore a constant temperature must be maintained during its 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.