Description

Potassium Hydrogen Phthalate (CAS NO 877-24-7) is a high-purity, crystalline salt of phthalic acid, widely recognized as a primary standard for acid-base titrations. Its exceptional purity, stability, and well-defined stoichiometry make it an indispensable reagent for ensuring analytical accuracy and method validation. This product is essential for laboratories and industries requiring precise calibration of pH meters and volumetric solutions, serving the pharmaceutical, chemical analysis, food testing, and educational sectors.

Application

• Primary Standard for Acid-Base Titrimetry: Used for the precise standardization of sodium hydroxide, potassium hydroxide, and other basic volumetric solutions.
• pH Meter Calibration: Serves as a key buffer component in standard buffer solutions for calibrating pH electrodes, especially in the pH range of approximately 4.0.
• Analytical Chemistry Reference Material: Employed in quality control laboratories to validate analytical methods and ensure the accuracy of titration equipment.
• Pharmaceutical Testing: Used in compendial testing (e.g., USP, EP) for assay methods and other quantitative analyses requiring a high-purity acidimetric standard.
• Food & Beverage Analysis: Applied in the determination of acidity and for calibrating instruments used in food safety and quality control protocols.
• Educational & Research Laboratories: A fundamental reagent for teaching principles of analytical chemistry, stoichiometry, and solution preparation.

Basic Information

Product Name	Potassium Hydrogen Phthalate
CAS No.	877-24-7
Molecular Formula	C8H5KO4
Molecular Weight	204.22 g/mol
Synonyms	Potassium Biphthalate; KHP; Phthalic Acid Monopotassium Salt; 1,2-Benzenedicarboxylic Acid Monopotassium Salt; Potassium Acid Phthalate; Potassium Hydrogen Phthalate, Primary Standard; Acid Potassium Phthalate; IUPAC: Potassium hydrogen benzene-1,2-dicarboxylate
EINECS	212-889-4

Quality Control

Our Potassium Hydrogen Phthalate is manufactured and tested to meet the stringent requirements of a primary standard. Production adheres to current Good Manufacturing Practices (cGMP) and is supported by a comprehensive quality management system. Each batch is accompanied by a detailed Certificate of Analysis (COA) providing full traceability and confirming compliance with relevant pharmacopoeial standards such as USP, EP, and ACS reagent grade specifications. Our products undergo rigorous quality testing to ensure compliance with industry standards. Certificates of Analysis (COA) are available upon request.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at a controlled room temperature (15-25°C). The product is hygroscopic (moisture-sensitive); the container must be kept tightly sealed to prevent absorption of atmospheric moisture, which can affect purity and weight.

Specification

Item	Specification
Appearance	White crystalline powder
Identification (IR)	Conforms
Assay (Titration)	≥ 99.95%
pH (5% solution, 25°C)	3.8 - 4.2
Loss on Drying	≤ 0.05%
Insoluble Matter	≤ 0.005%
Chloride (Cl)	≤ 0.001%
Sulfate (SO4)	≤ 0.003%
Heavy Metals (as Pb)	≤ 0.0005%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.