The precise control of pH is a cornerstone of successful experimentation in chemistry, biochemistry, and molecular biology. Among the arsenal of buffering agents available to scientists, N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES) stands out due to its advantageous chemical characteristics. As a zwitterionic compound, BES exhibits amphoteric properties, meaning it can act as both an acid and a base, making it highly effective at resisting changes in pH. This article delves into the fundamental chemical properties of BES that contribute to its widespread use and reliability.

At its core, BES is an organic compound with the molecular formula C6H15NO5S and a molecular weight of 213.25 g/mol. Its structure features a central amino group flanked by two hydroxyethyl groups, and an ethanesulfonic acid moiety. This unique arrangement gives rise to its zwitterionic nature, where the sulfonic acid group is deprotonated (carrying a negative charge) and the amino group can be protonated (carrying a positive charge) within a certain pH range. This internal charge separation contributes to its high water solubility and its effectiveness as a buffer.

The most critical chemical property of BES for buffering applications is its pKa, which is approximately 7.15 at 20°C. The pKa represents the pH at which the concentration of the protonated form of the buffer equals the concentration of its deprotonated form. Buffers are most effective at maintaining pH close to their pKa, typically within one pH unit above or below. Therefore, BES is an excellent choice for experiments requiring a stable pH in the range of approximately 6.4 to 7.8. This range encompasses the physiological pH of many biological systems, making BES particularly valuable in life science research. The ability to buy BES of high purity ensures that this critical pKa value is accurate and consistent.

Beyond its pKa, the chemical stability of BES is another key attribute. It is generally stable under normal laboratory conditions and does not readily decompose or react with other common reagents, which is vital for long-term experiments or for use in complex reaction mixtures. Its low UV absorbance is also a significant chemical property, as it minimizes interference with spectroscopic measurements, a common detection method in many biochemical assays. Understanding the chemical synthesis of BES can also provide insight into its purity and potential impurities, which is important when considering price and source from manufacturers like NINGBO INNO PHARMCHEM CO.,LTD.

In conclusion, the chemical structure and properties of N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES) – its zwitterionic nature, precise pKa, chemical stability, and low UV absorbance – collectively make it a superior buffering agent. These attributes are foundational to its successful application in demanding scientific disciplines, enabling researchers to achieve accurate and reproducible results by providing robust pH control. The consistent availability of BES from reputable suppliers ensures that these critical chemical properties remain accessible to the scientific community.