Organic solvents offer several key advantages compared to water in various applications, particularly in separation techniques.
Based on assertions in the literature, the general advantages of organic solvents over water include enhanced separation characteristics and the ability to utilize different electrical parameters.
Here are the primary benefits identified:
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Increased Separation Selectivity: Organic solvents can improve the ability to distinguish between different components in a mixture. This means that compounds with similar properties might be separated more effectively in an organic medium than in water. The interaction of the solvent with the sample molecules and the stationary phase (if applicable) differs significantly from water, leading to unique separation behaviors.
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Increased Separation Efficiency: Beyond just separating different components, organic solvents can also improve the overall efficiency of the separation process. This often translates to sharper peaks and better resolution in chromatographic or electrophoretic techniques, allowing for more accurate quantification and analysis of separated substances.
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Ability to Use High Separation Voltages and/or High BGE Ionic Strengths: In certain separation methods, such as capillary electrophoresis, the electrical properties of the solvent are crucial. Organic solvents generally have lower electrical conductivity than water. This property allows for the application of higher separation voltages without generating excessive heat (Joule heating), which can degrade the sample or the separation medium. Furthermore, higher background electrolyte (BGE) ionic strengths can sometimes be employed, offering greater control over migration times and peak shapes.
These advantages highlight why organic solvents are often preferred or necessary for specific applications, particularly when dealing with non-polar or weakly polar compounds that interact poorly with water, or when precise control over electrical parameters is required for optimal separation performance.
