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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

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About This Item

Empirical Formula (Hill Notation):
C8H5KO4
CAS Number:
877-24-7
Molecular Weight:
204.22
UNSPSC Code:
41116107
EC Index Number:
212-889-4
NACRES:
NA.24
MDL number:
MFCD00013070
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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

SMILES string

[K+].[O-]C(=O)c1c(cccc1)C(=O)[O-].[H+]

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

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

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Storage Class

11 - 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

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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