In scientific laboratories, precision and accuracy are paramount. Phenolphthalein (CAS 77-09-8) stands as a cornerstone reagent, most famously utilized as a pH indicator in titrations. For R&D scientists and laboratory technicians, understanding the nuances of this chemical, particularly its purity and sourcing, is critical for achieving reliable experimental outcomes. This article highlights the importance of high-quality Phenolphthalein for laboratory applications and how to secure it from trusted suppliers.

The Indispensable pH Indicator

Phenolphthalein's utility as a pH indicator stems from its distinct color transition. In acidic to neutral solutions (pH < 8.5), it remains colorless. As the solution becomes alkaline, it transitions through a faint pink to a deep red color in strongly alkaline conditions (pH > 9). This clear visual cue makes it ideal for determining the endpoint in acid-base titrations, a fundamental technique in quantitative chemical analysis. The range of its color change (pH 8.5–10.0) is precisely suited for titrating weak acids with strong bases.

For laboratory use, the purity of Phenolphthalein directly impacts the accuracy of results. Impurities can interfere with the color transition, leading to erroneous endpoint determination. Therefore, when you seek to buy Phenolphthalein USP grade, you are opting for a standard that guarantees a high level of purity and minimal interference. This is especially important for qualitative and quantitative analytical reagents used in critical testing and research.

Choosing the Right Phenolphthalein Supplier

When sourcing laboratory reagents, consider the following:

  • Grade and Purity: Opt for USP, AR (Analytical Reagent), or equivalent grades. High assay percentages (e.g., 99% or higher) are desirable.
  • Supplier Reliability: Partner with established chemical suppliers known for consistent quality and dependable delivery.
  • Certificates of Analysis (CoA): Request a CoA with each batch to verify purity, physical properties, and adherence to specifications.
  • Traceability: Ensure the product has proper labeling and batch traceability for quality assurance purposes.

For those looking for a reliable Phenolphthalein chemical intermediate supplier, researching manufacturers who also cater to the laboratory reagent market is beneficial. Understanding the 77-09-8 price for laboratory reagents requires comparing offerings from various reputable sources. By focusing on quality and consistency, researchers can ensure their laboratory work, from routine titrations to complex analytical procedures, is performed with the utmost accuracy and reliability, underpinned by superior reagents sourced from a trusted high purity Phenolphthalein manufacturer.