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When is a microscale boiling point determination using a capillary tube used?

Answer :

Final answer:

Microscale BP determination using a capillary tube is used in analytical chemistry to manage and analyze very small sample volumes with high precision, often in the range of microliters or picoliters.

Explanation:

A microscale BP (boiling point) determination using a capillary tube is often performed when dealing with very small quantities of a substance, particularly when the available sample size is on the scale of microliters (µL) or picoliters (pL). In such cases, a capillary tube, which typically has a small internal diameter ranging from 25-75 µm, is utilized to contain and manage the tiny sample volume effectively. The method relies on the capillary action of the tube to manipulate the sample. This procedure is instrumental in analytical chemistry, where precision and the ability to analyze small volumes are crucial.

Capillary tubes are also characterized by their mechanical strength, provided by a polyimide coating, and their use in various injection methods like hydrodynamic and electrokinetic injections. These methods ensure accurate sample introduction into analytical instruments such as capillary electrophoresis (CE) systems. However, due to the challenges in controlling the temperature and viscosity of solutions, the injection volume can vary, and therefore, internal standards are recommended for quantitative analysis.