microburettes

Microburettes are miniature burettes designed for the precise dispensing of small volumes of titrant in quantitative chemical analyses. They provide a compact capacity and fine graduations, enabling titrations where only microliter to low-milliliter additions are needed or where sample conservation is important. Microburettes are used in microtitrations, trace analysis, pharmaceutical testing, and automated systems that require small-volume titration steps.

Construction and operation: Microburettes resemble standard burettes but on a smaller scale. They are typically made of borosilicate glass with a narrow bore and a controlled-volume tip, and they are equipped with a stopcock to regulate flow. Graduations commonly range from 0.01 mL to 0.1 mL, depending on model. Users fill the instrument with titrant, ensure the absence of air bubbles, and deliver the liquid by opening the stopcock. Readings are taken from the bottom of the meniscus at eye level; graduation marks usually increase downward.

Applications and performance: Microburettes are used in acid–base, redox, complexometric, and other titrations when small, accurate additions are required. They can be integrated into automatic titration systems or operated manually. The advantages include reduced reagent consumption and improved control over small-volume additions; limitations include sensitivity to leaks, diffusion of the titrant into the sample, and the need for careful calibration and temperature control.

Care and calibration: Regular calibration against a reference standard helps ensure accuracy. Maintenance includes cleaning with appropriate solvents, lubricating the stopcock with compatible grease if required, and storing the device upright to prevent contamination. Users should verify zero and consider potential parallax errors and temperature effects to maintain precision.