The limitations of traditional NaOH titration method

In clinical biochemical testing, serum bicarbonate (HCO ∝⁻) content is one of the important indicators for evaluating the acid-base balance of the body. The measurement method usually uses acid-base titration, which involves adding an excess of standard hydrochloric acid solution to the serum sample to react HCO ∝⁻ with H ⁺ to generate carbon dioxide and water. Then, the remaining hydrochloric acid is titrated with standard alkaline solution to calculate the concentration of HCO ∝⁻.

Tris base powder

In traditional methods, 0.01mol/L sodium hydroxide (NaOH) is commonly used as the titrant. However, NaOH solution has obvious drawbacks: it easily absorbs carbon dioxide from the air, causing changes in solution concentration and affecting the accuracy of titration results. Therefore, NaOH solution requires daily calibration titration, which is cumbersome to operate and prone to introducing errors.

The advantages of Tris as an alternative titrant

In recent years, Tris base has been gradually applied in the determination of serum bicarbonate due to its excellent chemical stability and good titration performance, and has demonstrated significant technical advantages.

2.1 Tris is an ideal monovalent organic base

The molecular formula of Tris is C ₄ H ₁₁ NO3, with a molecular weight of 121.14. The pH value of its 0.1mol/L aqueous solution is about 10.36, and it can undergo complete neutralization reaction with strong acids such as hydrochloric acid, ensuring the thoroughness of titration reaction. This enables Tris to have high reaction efficiency and accuracy in acid-base titration.

2.2 Easy to weigh and prepare, low moisture absorption

Compared to NaOH (molecular weight 40), Tris has a larger molecular weight, lower hygroscopicity, and is less susceptible to environmental humidity. It can be accurately weighed without the need for drying treatment. In addition, Tris has a high solubility in water, with about 80g dissolved in 100mL of water at room temperature, which facilitates the rapid preparation of high concentration solutions and improves experimental efficiency.

2.3 Good solution stability, no need for frequent calibration

Tris solution is chemically stable at room temperature and does not react significantly with CO ₂ in the air, avoiding concentration changes caused by CO ₂ dissolution. Experimental results have shown that Tris solution does not require calibration within one month, and the color indicator endpoint is stable, simplifying the daily operation process.

2.4 Clear indicator endpoint, easy to judge

During the titration process, methyl red is used as an indicator, and the endpoint is when the solution changes from red to yellow. The color change is significant and lasts for a long time, with no fading or discoloration within 30 minutes. In contrast, NaOH titration often uses phenol red as an indicator, and it is difficult to grasp the color change of the endpoint. A slight delay may lead to misjudgment.

Desheng New Materials: A Professional TRIS Supplier

Behind this technological advancement, the support of high-quality raw materials is indispensable. As a professional domestic supplier of biological buffering agents, Desheng New Materials focuses on the research and production of high-performance biochemical reagents, covering various buffering system products such as Tris, HEPES, MOPS, etc. Desheng New Materials has a sound quality control system and advanced synthesis technology to ensure that each batch of products has high purity, high stability, and good batch consistency. Our company's products not only meet the needs of the domestic market, but are also exported overseas, winning the trust and praise of our customers.

Product packaging

Desheng New Materials: A Professional TRIS Supplier

Behind this technological advancement, the support of high-quality raw materials is indispensable. As a professional domestic supplier of biological buffering agents, Desheng New Materials focuses on the research and production of high-performance biochemical reagents, covering various buffering system products such as Tris, HEPES, MOPS, etc. Desheng New Materials has a sound quality control system and advanced synthesis technology to ensure that each batch of products has high purity, high stability, and good batch consistency. Our company's products not only meet the needs of the domestic market, but are also exported overseas, winning the trust and praise of our customers.