CAMAG® TLC Scanner 4

The TLC Scanner 4 is a scanning densitometer. It measures the reflection of separated compounds in absorption and/or fluorescence mode. Controlled by visionCATS software the TLC Scanner 4 enables quantitative evaluation of the generated densitometric data. The spectral range of light from 190 to 900 nm is available for selecting single or multiple wavelengths for scanning densitometry. Detection can thus be fine-tuned to match the spectral properties of the analyte to its optimized specificity and sensitivity of the detection.

Evaluation with visionCATS

visionCATS controls the TLC Scanner 4 and enables quantitative evaluation of the generated densitometric data. To determine the substance concentration in a sample, five different quantification functions (e.g. linear and polynomial) are available. Several scanning steps (e.g. scanning the plate after development and scanning the same plate after derivatization) and up to five different evaluations can be performed (with data obtained from single wavelength, multiple wavelengths or a combination of measurements in absorption and fluorescence detection mode).

The Scanner Ultimate Package:

• Multi Wavelength Scan: this feature offers the possibility to perform a multi-wavelength scan with up to 31 selected wavelengths or a combination of measurements in absorption and fluorescence detection mode.
• Scanner Quantification: this feature allows to quantify each individual substance on the plate. Five different quantification functions are available for evaluation to determine the concentration of the substance in a sample. In one analysis file up to five evaluation steps can be performed in multiple plate states (e.g. plate after development and same plate after derivatization).
• Spectrum Scan: this feature includes the measurement of the spectrum of each individual substance on the plate including the evaluation of the substance purity by comparison with reference standard.

The Optical System

• Any of the three light sources, high pressure mercury lamp, deuterium lamp, or halogen-tungsten lamp can be positioned in the light path by a motor drive. (1)
• The signal of the measuring photomultiplier is continuously offset against the signal of the reference photomultiplier. (4 and 5) This compensates for lamp aging and short-time fluctuations. It also reduces the warm-up time required to reach lamp stabilization.
• All components of the optical system, lamps, monochromator, scanning stage, and photomultiplier are mounted on one sturdy metal support. This ensures high precision of the detector signal.
• For scanning at wavelengths below 200 nm it is advisable to flush the monochromator with nitrogen. The TLC Scanner 4 is equipped to do this.
• A monochromator bandwidth of 5 nm or 20 nm can be selected. 5 nm bandwidth is used for spectra recording, multi-wavelength scanning, and when spectral selectivity is required. (2) 20 nm bandwidth offers higher light intensity (improves the signal to noise ratio and thus the reproducibility of the measurement) and enables measurement of several fractions with slightly different absorption maxima in one scan.
• The lens system with 190 – 900 nm transmission range features automatic positioning for micro and macro slit sizes. This ensures that the light energy available with small slits in the micro position is almost the same as that for the corresponding slit in the macro position, which is four times larger. (3)
• The light beam strikes the object at right angle. The photomultiplier is aligned at an angle of 30°. (5)