1.01965

Potassium hydrogen phthalate

certified secondary standard reference material for pH measurement; directly traceable to primary SRM from NIST/PTB pH(S) = 4.00₅ (25°C) Certipur^®

• Synonym(s): Potassium hydrogen phthalate, KHP, Monopotassium phthalate, Phthalic acid monopotassium salt, Potassium biphthalate, Potassium phthalate monobasic
• Empirical Formula (Hill Notation): C₈H₅KO₄
• CAS Number: 877-24-7
• Molecular Weight: 204.22
• MDL number: MFCD00013070
• UNSPSC Code: 41116107
• EC Index Number: 212-889-4
• NACRES: NA.24

Properties

• grade: certified reference material
• Quality Level: 300
• Agency: complies with DIN 19266
• product line: Certipur^®
• potency: >3200 mg/kg LD₅₀, oral (Rat)
• pH: 4.0 (20 °C, 50 g/L in H₂O)
• mp: 295-300 °C
• solubility: 80 g/L
• density: 1.636 g/cm³
• bulk density: 900 kg/m³
• application(s): environmental; food and beverages; general analytical; industrial qc; pharmaceutical
• format: neat
• storage temp.: 15-25°C
• InChI: 1S/C8H6O4.K/c9-7(10)5-3-1-2-4-6(5)8(11)12;/h1-4H,(H,9,10)(H,11,12);/q;+1/p-1
• InChI key: IWZKICVEHNUQTL-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 hydrogen phthalate [KHP; pH(S) = 4.00₅ (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) = 4.00₅ (25 °C)].
• This buffer standard has a guaranteed shelf life of 4 years.
• Potassium hydrogen phthalate buffer is a Certified Reference Material (CRM) offered in neat format. Solution of this standard can be prepared in-house per 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.

Legal Information

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

Safety Information

• Storage Class Code: 13 - Non Combustible Solids
• WGK: WGK 1
• Flash Point(F): 387.1 °F - Pensky-Martens closed cup
• Flash Point(C): 197.3 °C - Pensky-Martens closed cup