1.99054

Buffer solution

(citric acid/sodium hydroxide/hydrogen chloride) colour: red, traceable to SRM from NIST and PTB pH 4.00 (25 °C), Certipur^®

• Synonym(s): Buffer solution pH 4.0 (25 °C in H2O) (citric acid/sodium hydroxide/hydrogen chloride)
• UNSPSC Code: 12161703
• NACRES: NA.25

Properties

• grade: certified reference material
• Quality Level: 300
• product line: Certipur^®
• pH: 4.0 (25 °C in H₂O)
• density: 1.00 g/cm³ at 20 °C
• application(s): environmental; food and beverages; general analytical; industrial qc; pharmaceutical
• format: mixture
• storage temp.: 15-25°C

Description

General description

This red-colored 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 in a secure 500 mL plastic bottle and 4 L innovative and sustainable Titripac^® PE/Aluminum packaging for a reduced waste generation
• 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

Legal Information

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

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

Safety Information

• Storage Class: 12 - Non Combustible Liquids
• wgk_germany: WGK 1
• flash_point_f: Not applicable
• flash_point_c: Not applicable