HPTLC |
HPTLC (high-performance thin layer chromatography) is a sophisticated form of TLC, which provides superior separation efficiency. The HPTLC concept includes validated methods for qualitative and quantitative analysis, and fulfills all quality requirements for use in fully regulated environments.
The process steps of HPTLC are identical to classical TLC. The main difference between them is in the characteristics of the separation plate. HPTLC plates are based on optimized silica gel 60 with a significantly smaller particle size than used for classical TLC. This allows a higher packing density and a smoother surface. Hence, sample diffusion is reduced, resulting in compact bands or spots. Furthermore, the smaller particle size and thinner layer significantly increase detection sensitivity and analysis speed.
Features of HPTLC versus classical TLC |
HPTLC |
Classical TLC | |
---|---|---|---|
Mean particle size | 5 - 6 µm | 10 - 12 µm | |
Particle size distribution | 4 - 8 µm | 5 - 20 µm | |
Layer thickness | 200 µm (100 µm) | 250 µm | |
Plate height | 12 µm | 30 µm | |
Typical migration distance | 3 - 6 cm | 10 - 15 cm | |
Typical separation time | 3 - 20 min | 20 - 200 min | |
Number of samples per plate | < 36 (72) | < 10 | |
Sample volume | 0.1 - 0.5 µl | 1 - 5 µl | |
Detection limits: absorption | 100 - 500 pg | 1 - 5 ng | |
Detection limits: fluorescence | 5 - 10 pg | 50 - 100 pg |
The separations below demonstrate the advantages of HPTLC over TLC.
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Comparison of the separation of dansyl amino acids under identical conditions. The comparison clearly demonstrates that the HPTLC plate delivers sharper zones with shorter migration distances and faster analysis times. In addition the HPTLC plate allows these separation of twice the number of samples simultaneously.
HPTLC plates offer superior separation performance for quantitative evaluation of highly complex samples in:
Comparison of detection limits on HPTLC LiChrospher® Si 60 F254s plates and normal HPTLC Si 60 F254 plates (Detection Limits, UV 254 nm, ng/spot).
Substance |
Visually |
Spectrophotometrically | ||
---|---|---|---|---|
Silica gel 60 F254 |
LiChrospher® Si 60 F254s |
Silica gel 60 F254 |
LiChrospher® Si 60 F254s | |
Ascorbic acid | 100 | 100 | 100 | 25 |
Cortisone | 50 | 25 | 25 | 10 |
Atrazine | 50 | 25 | 10 | 5 |
Prometryne | 25 | 10 | 10 | 5 |
Theophylline | 50 | 25 | 25 | 10 |
o-Aminophenol | 50 | 25 | 25 | 5 |
m-Aminophenol | 10 | 5 | 10 | 5 |
p-Aminophenol | >100 | 50 | 50 | 25 |
Scanning electron pictures of the cross-section
Pesticide separation | ||
---|---|---|
Sample | 1. Hexazinone | |
2. Metoxuron | ||
3. Monuron | ||
4. Aldicarb | ||
5. Azinphos-methyl | ||
6. Prometryn | ||
7. Pyridate | ||
8. Trifluralin | ||
Sample volume | 50 nl | |
Mobile phase | Petroleum benzene 40 - 60°C / acetone 70/80 | |
Detection | 5 - 10pg |
CAMAG HPTLC Application Tutorial