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Why don’t I see any spots on my TLC plate?
Possible causes:
- Sample concentration is too low.
- Analytes are not UV-active or lack chromophores.
Solution: Concentrate the sample or use a staining reagent.
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What could cause my TLC plate to develop unevenly?
- The plate is tilted during development.
- Solvent evaporation during development.
Solution: Ensure the plate is level and use a saturated chamber.
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Why do my spots streak or tail on the TLC plate?
Possible causes:
- Overloading the sample.
- Using an inappropriate solvent system.
- Poor sample solubility.
Solution: Dilute the sample, optimize the solvent system, or ensure complete dissolution.
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What is the maximum temperature the plates can withstand?
Most TLC plates can tolerate up to 200°C during drying. Always refer to the manufacturer’s guidelines.
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Do you offer TLC plates with fluorescent indicators?
Yes, many plates are pre-coated with UV254 or UV366 indicators to aid visualization under UV light.
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What is the typical particle size and thickness of the TLC layer?
Particle size is typically 5 – 20 µm. Analytical TLC layers are usually 250 µm (0.25 mm) thick, while preparative layers are 500 – 2,000 µm (0.5 – 2 mm) thick.
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What is the proper way to apply samples on a TLC plate?
Use a capillary tube or micropipette to spot small, consistent volumes (1 – 2 µL) on the baseline. Ensure spots are evenly spaced.
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How do I visualize the spots on the TLC plate?
Use UV light for fluorescent indicators, iodine vapors for certain organic compounds, or chemical stains like ninhydrin or sulfuric acid for others.
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Can I reuse TLC plates?
TLC plates are generally single-use due to contamination. For training or non-critical uses, plates can sometimes be cleaned and reused with solvents.
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How should I store TLC plates to maintain their quality?
Store plates in a dry, cool place, preferably in a desiccator, to prevent moisture absorption.
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What’s the difference between normal-phase and reverse-phase TLC plates?
- Normal phase: Silica or alumina adsorbents are used for non-polar to moderately polar compounds.
- Reverse phase: C18 or C8-coated silica is used for polar compounds or aqueous mobile phases.
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What is the sensitivity of TLC plates for my analytes?
Sensitivity depends on the detection method. With UV indicators, compounds absorbing at 254 nm or higher are easily detected.