HPTLC is a very advanced planar chromatography method that has developed out of the conventional Thin Layer Chromatography (TLC) on a very high standard of automation, reproducibility, and data analysis. These services are important in identity checking, purity analysis, stability analysis, and adulteration analysis, particularly with natural products whose chemical structure is complicated.
Fundamental Principles
HPTLC works under these same principles as TLC: separation by differences in the movement of compounds between a stationary phase (a high-quality silica gel or any other adsorbent layer on a plate) and a mobile phase (solvent system). The high-performance element is due to a smaller particle size (5-7 µm) and a smaller size distribution of the adsorbent, resulting in high efficiency and resolution. High throughput nanolitre volumes with automated and accurate spray-on deposition of the sample, removing human error regarding manual spotting. Development in the uniform development of solvents, in either twins or automated developing chambers (ADC) with saturation pads to allow uniform solid front development.
Limitations and Service Considerations
Poor Separation of Highly Complex Mixtures: Although it is better than TLC, it does not have high peak capacity in samples with hundreds of closely related compounds, as compared to HPLC or GC. Limitations of quantification: The sensitivity (usually in the microgram range) is normally lower than that of HPLC-MS. This is because method development requires the skill of the chromatographer to develop the method. Plate-to-Plate Variability: Despite automation, some variability may exist, whereby standards have to be used on every plate. The clients will have to screen the service providers based on their experience with the sample type in question.
Selecting an HPTLC Testing Service Provider
The crucial selection criteria include Accreditation: A certification of some of the test methods is granted by ISO/IEC 17025. The time in the industry: The record of success in dealing with the product line of the client (e.g., herbal supplements, spices). Instrumentation: Current, modern-day HPTLC systems (e.g., CAMAG). Validity of methods Capability: Capability to establish and validate methods based on ICH or other guidelines. Data Delivery and Reporting: Report transparency, electronic pictures, and raw data delivery. Turnaround Time & Cost Structure. Regulatory Support: The information on the methods of data preparation to be provided to the FDA or the EU, among other regulatory authorities.
