What is the main principle behind liquid chromatography?
Explanation: The correct answer is D) Separation based on differential interaction between the analyte and stationary/mobile phases. Liquid chromatography separates components of a mixture based on their differential interaction with the stationary phase (e.g., solid support or liquid immobilized on a solid support) and the mobile phase (liquid solvent). The components in the mixture interact differently with the stationary and mobile phases, leading to their separation.
What is the stationary phase in liquid chromatography?
Explanation: The correct answer is C) Solid support or liquid immobilized on a solid support. In liquid chromatography, the stationary phase is typically a solid support or a liquid immobilized on a solid support. The stationary phase provides selectivity for separating components based on their chemical properties. Different types of stationary phases can be used, such as reversed-phase (non-polar) or normal-phase (polar) columns, depending on the analytes of interest.
Which type of liquid chromatography uses a non-polar stationary phase and a polar mobile phase?
Explanation: The correct answer is A) Reversed-phase chromatography. Reversed-phase chromatography uses a non-polar stationary phase (e.g., hydrophobic) and a polar mobile phase (e.g., water or organic solvent). The analytes in the mixture interact more with the mobile phase than the stationary phase, leading to their separation based on their hydrophobicity. Reversed-phase chromatography is widely used in various applications, including pharmaceutical analysis and protein purification.
What is the purpose of the detector in liquid chromatography?
Explanation: The correct answer is D) Detecting and measuring the analytes. The detector in liquid chromatography is responsible for detecting and measuring the analytes as they elute from the column. It detects the presence and quantity of analytes based on their chemical or physical properties. Common types of detectors used in liquid chromatography include UV-Visible detectors, fluorescence detectors, refractive index detectors, and mass spectrometry detectors.
What does the retention time represent in liquid chromatography?
Explanation: The correct answer is C) The time it takes for the analyte to interact with the stationary phase. Retention time in liquid chromatography represents the time it takes for an analyte to interact with the stationary phase and travel through the column to reach the detector. It is a characteristic property of each analyte and can be used for identification and quantification purposes. The retention time depends on various factors, including the analyte's chemical properties and the column conditions.