1.01961

Potassium tetraoxalate dihydrate

certified secondary standard reference material for pH measurement; directly traceable to primary reference material from NIST/PTB pH (S) = 1.67₉ (25°C) Certipur^®

• Synonym(s): Potassium tetraoxalate dihydrate, Oxalic acid hemipotassium salt, Potassium hydrogen oxalate-oxalic acid-water (1/1/2)
• Empirical Formula (Hill Notation): C₄H₃KO₈ · 2H₂O
• CAS Number: 6100-20-5
• Molecular Weight: 254.19
• MDL number: MFCD00150443
• UNSPSC Code: 41116107
• EC Index Number: 204-874-6
• NACRES: NA.24

Properties

• grade: certified reference material
• Quality Level: 300
• agency: complies with DIN 19266
• product line: Certipur^®
• pH: 1.7 (25 °C, 12.6 g/L in H₂O)
• solubility: 25 g/L
• density: 1.84 g/cm³ at 20 °C
• bulk density: 860 kg/m³
• application(s): environmental; food and beverages; general analytical; industrial qc; pharmaceutical
• format: neat
• storage temp.: 15-25°C
• InChI: 1S/2C2H2O4.K/c2*3-1(4)2(5)6;/h2*(H,3,4)(H,5,6);/q;;+1/p-1
• InChI key: GANDVAJEIJXBQJ-UHFFFAOYSA-M

Description

General description

Certipur^® certified secondary standard reference buffers are used to precisely calibrate and monitor pH measurement instruments and buffer solutions. They are quality controlled and qualified in our ISO/IEC 17025 and ISO 17034 accredited calibration laboratories against certified primary standard reference materials (SRM) in compliance with DIN 19266, IUPAC, NIST, Ph. Eur and USP. Certipur^® reference materials offer maximum accuracy, reliability and convenience and help avoid costly repeat analyses.

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

Potassium tetraoxalate dihydrate [pH (S) = 1.67₉ (25 °C)] is a certified secondary standard reference material used as a calibration buffer standard for pH instruments or pH electrodes.

Features and Benefits

• The product is delivered with a comprehensive, batch-specific Certificate of Analysis showing the relevant data for the quality management system.
• The pH value of this Certipur^® buffer solution is qualified using differential potentiometry with two platinum hydrogen electrodes against NIST & PTB primary reference materials [pH (S) = 1.679 (25 °C)].
• This buffer standard has a guaranteed shelf life of 4 years.
• Potassium tetraoxalate dihydrate buffer is a Certified Reference Material (CRM) offered in neat format. Solution of this standard is prepared in-house following instructions in European Pharmacopoeia (Ph. Eur. 2.2.3).
• Intended for extremely precise calibration, qualification and monitoring of pH instruments and routine assessment of their performance.

Analysis Note

pH-value (25 °C): 1.674 - 1.683

Legal Information

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

Safety Information

• pictograms: GHS07
• signalword: Warning
• hcodes: H302 + H312 - H319
• pcodes: P264 - P270 - P280 - P301 + P312 - P302 + P352 + P312 - P305 + P351 + P338
• Hazard Classifications: Acute Tox. 4 Dermal - Acute Tox. 4 Oral - Eye Irrit. 2
• Storage Class: 11 - Combustible Solids
• wgk_germany: WGK 1