Sigma-Aldrich Buffer Solution pH 4.00 (2

Grade

certified reference material

Quality Level

300

Product Line

Certipur^®

pH

4.0 (25 °C in H₂O)

Density

1.01 g/cm³at 20 °C

Application(S)

environmental
food and beverages
general analytical
industrial QC
pharmaceutical

Format

mixture

Storage Temp.

15-25°C

Related Categories

Physical & Chemical Property Standards

General Description

The citric acid/sodium hydroxide/hydrogen chloride buffer solution is gravimetrically prepared at a registered calibration laboratory with high-quality reagents and water. Its pH value of 4.00 at 25°C is measured using a combined glass electrode following a 5-point calibration method. The measurement is made following DIN 19268 using reference buffer solutions compliant to DIN 19266, NIST, IUPAC, pH. Eur, and USP. The buffer pH is temperature dependent 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.

Application

The buffer is used as a standard to calibrate pH measuring instruments or pH electrodes and as a control 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 standard from NIST and primary certified reference standard from PTB
• Available as a ready-to-use solution 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
• An uncertainty of +/- 0.02 in the pH value at 25°C

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