Q.4 In reverse-phase liquid chromatography, stationary phase is:
- Polar
- Non-polar
- Hydrophilic
- Ionic
In reverse-phase liquid chromatography (RPLC), the stationary phase is non-polar, typically featuring hydrophobic alkyl chains like C18 bonded to silica.
Introduction
Reverse-phase liquid chromatography stationary phase relies on non-polar materials for separating polar to non-polar analytes in molecular biology and biotech applications. This technique reverses normal-phase setups, using polar mobile phases with hydrophobic columns.
RPLC Fundamentals
RPLC uses a non-polar stationary phase (e.g., C18 or C8 alkyl silica) and polar mobile phase (water-acetonitrile mix). Non-polar analytes interact strongly with the stationary phase via hydrophobic forces, eluting later; polar ones elute first. This setup excels in protein purification and PCR product analysis.
Option Breakdown
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Polar: False. Polar stationary phases suit normal-phase chromatography, not RPLC where hydrophobicity drives retention.
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Non-polar: True. Alkyl chains (C18) on silica create a hydrophobic, non-polar surface for reversed-phase separations.
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Hydrophilic: False. Hydrophilic phases attract water; RPLC requires the opposite for non-polar retention.
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Ionic: False. Ionic phases enable ion-exchange chromatography, not the hydrophobic mechanism of RPLC.
Option Property Correct for RPLC? Role in Chromatography Polar Water-attracting No Normal-phase use Non-polar Hydrophobic alkyl chains Yes RPLC retention Hydrophilic Water-loving No HILIC alternative Ionic Charge-based No Ion-exchange Applications in Biotech
RPLC separates biomolecules like peptides in proteomics or nucleotides in genetic analysis, aiding exam prep in plant sciences and molecular biology.
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