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Buffer solution

(citric acid/sodium hydroxide/hydrogen chloride), traceable to SRM from NIST and PTB pH 4.00 (20°C) Certipur®

Quality Level


certified reference material

product line



4.0 (25 °C in H2O)


1.01 g/cm3 at 20 °C

Featured Industry

Food and Beverages
General Analytical
Industrial QC



storage temp.


General description

The buffer solution (citric acid/sodium hydroxide/hydrogen chloride) is gravimetrically prepared using high-quality reagents in high-purity water. It is quality controlled and qualified in an ISO/IEC 17025 accredited calibration lab. Its pH value of 4.00 at 20°C is qualified using a combined glass electrode following a 5-point calibration method, in accordance with DIN 19268, against certified primary reference standards as per DIN 19266, IUPAC, NIST, USP, and Ph. Eur.


It is used in analytical procedures for calibration, qualification, and monitoring of pH measuring instruments and as a control for testing other buffer solutions.

Features and Benefits

  • Measured and qualified in 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 an innovative Titripac® packaging for positive environmental impact due to reduced waste generation
  • Long-lasting with a shelf life of 3 years
  • Accompanied with a batch-specific and detailed certificate of analysis (CoA) for an effective audit

Legal Information

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

Storage Class Code

12 - Non Combustible Liquids

WGK Germany


Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

Certificate of Origin

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

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