21 CFR Part 11

FDA 21 CFR Part 11: requirements for electronic records and electronic signatures

2D view

a two-dimensional representation of geometric data. It is a planar representation.

3D view

a three-dimensional representation of geometric data.


is a scan-mode of the CAMAG® TLC Scanner 4 to determine the amount of a substance on a plate or to record a UV/VIS spectrum of a substance zone. The difference in absorbance between a reference position (no substance) and the sample track on the same plate is measured.


in physics is the take-up of electromagnetic radiation by molecules.


interaction with water molecules from the laboratory atmosphere changes the activity (the ability to adsorb molecules during chromatography) of silica gel (most common stationary phase) and thus affects the chromatographic results. A high amount of water in the atmosphere deactivates the plate, a dry atmosphere activates the plate. To standardize its chromatographic behavior, the plate is exposed to a defined relative humidity during “activation”. Activation at 33% relative humidity as available from a saturated MgCl2 solution is a standard procedure of HPTLC according to USP and Ph.Eur.


refers to the collection of molecules from gases or liquids on the surface of (porous) solids. Adsorption, a surface phenomenon, is often confused with absorption, which results in a mixture of substances.


is the quantity of a substance in a zone (expressed as mass, concentration, amount etc.).

analog offset

the value of the analog-digital converter (AD) that represents the measurement at the zero position. Unless this value is set to zero, the range below the offset value allows the AD converter to accept measurements of absorption and fluorescence values, which are below the zeroing position. This parameter is active only if detector mode has been set to manual.


in chromatography is the separation of a sample to determine identity (qualitative analysis) and proportions (quantitative analysis) of the sample components. In planar chromatography several samples / standards can be analyzed on one plate. In visionCATS the term Analysis covers the complete HPTLC procedure including sample preparation / definition / application / plate development / derivatization / chromatogram evaluation / documentation with respect to one specific plate. The resulting file is called analysis (data) file and has the file extension .paf.

analysis file

is the data file containing all information about one analysis. In visionCATS, the file has the extension “.paf”


the target compound(s) of an analysis


is used to add text, lines, rectangles, ellipses to the electronically captured image.


transfer of a defined sample volume onto a defined position of the plate.

application pattern

the geometrical application parameters like e.g. number of tracks, band length and track distance are defined (see also plate layout)

application position

is the distance in mm from the lower edge of the plate to the center of the applied spot / band in direction of chromatography (Y).

application type

indicates how the samples are applied: as spots, bands, or rectangles

application volume

the volume in μL which will be applied onto the plate


the area of a single peak in percentage of the total area of all peaks on the same track


is the arbitrary unit used in visionCATS to represent either the relative absorbance, fluorescence or luminance measured by the CAMAG® TLC Scanner 4 and the CAMAG® TLC Visualizer.


in HPTLC/TLC the detector signal obtained from the untreated, developed or derivatized plate, where it does not contain sample.


in scanning densitometry the bandwidth determines the range of wavelengths selected from the monochromator. At a selected wavelength of 540 nm and with a bandwidth of 20 nm, light between 530 and 550 nm will reach the plate.


is the calculated “zero” line from integration start to integration end. There are various mathematical routines to calculate a baseline for a chromatogram.

baseline correction

a routine or method to connect and align (straighten) the bases of all peaks in a chromatogram. visionCATS uses “lowest slope”, as default baseline correction algorithm.


either a polymeric or gypsum based additive added to the adsorbent, e.g. silica gel. It ensures a uniform and hard surface of the HPTLC/TLC plate that will not crack or blister.


is used in quantitative evaluation of chromatograms. It determines the functional correlation between the mass (concentration, amount) of analyte in the zone and the measured signal.

calibration curve

a graphical plot of the mathematical function calculated for a given calibration.

calibration mode

offers a selection of different calibration modes for quantitative evaluation. Available modes: single level calibration, and multi level calibration via linear, polynomial or Michaelis-Menten regression.

CAMAG ® Derivatizer

the CAMAG ® Derivatizer is an instrument for reproducible, automatic spraying of derivatization reagents onto the plate .

CAMAG® AMD 2 System Automated Multiple Development

the CAMAG® AMD 2 System Automated Multiple Development (AMD 2) is a software-controlled HPTLC chamber for gradient development. It is used for difficult analytical tasks that cannot be solved by isocratic HPTLC.

CAMAG® Automatic Developing Chamber 2 (ADC 2)

the CAMAG® Automatic Developing Chamber 2 is a fully automatic instrument for automatic conditioning, developing, and drying of HPTLC plates. The ADC 2 uses a 20x10 cm CAMAG® Twin Trough Chamber, controls chamber saturation and measures developing distances with a sensor. For conditioning the plate to a fixed relative humidity (the option “humidity control” allows reproducible chromatography at defined activity of the silica gel layer) and drying of the plate, the ADC 2 features a special compartment. Chromatography is terminated when the solvent front has reached the pre-set migration distance. The plate is then dried with high speed cold air.

CAMAG® Automatic TLC Sampler 4 (ATS 4)

the CAMAG® Automatic TLC Sampler 4 (ATS 4) is an instrument for fully-automated sample application onto TLC and HPTLC plates. Samples can be applied as bands, spots or rectangles.

CAMAG® Horizontal Developing Chamber

the CAMAG® Horizontal Developing Chamber is a separation device in which the plate is developed horizontally.


fully automated sample analysis and evaluation instruments using HPTLC plates (20 x 10 cm). CAMAG® HPTLC PRO is best suited for routine quality control of analytes extracted from complex matrices, providing reproducible and reliable results. It supports up to 75 samples, up to 5 plates, and up to 3 independent developing solvents without interference.


The CAMAG® HPTLC PRO SYSTEM consists of:


the CAMAG® HPTLC PRO Module APPLICATION is part of the HPTLC PRO - Fully-automated sample analysis and evaluation for routine quality control. It is used for spray application as bands of up to 75 sample extracts onto HPTLC plates (20 x 10 cm).


the CAMAG® HPTLC PRO Module DERIVATIZATION is part of the HPTLC PRO - Fully-automated sample analysis and evaluation for routine quality control. Derivatization is often used to visualize specific substance classes after separation on HPTLC glass plates (20 x 10 cm). Due to its unique and patented “micro droplet” spraying technology, the fully-automated HPTLC PRO Module DERIVATIZATION ensures homogeneity and reproducibility in applying derivatization reagents.


the CAMAG® HPTLC PRO Module DEVELOPMENT is part of the HPTLC PRO - Fully-automated sample analysis and evaluation for routine quality control. The chamber of the CAMAG® HPTLC PRO Module DEVELOPMENT is designed to separate analytes using optimized parameters (activation and pre-conditioning of the HPTLC glass plate (20 x 10 cm) before, conditioning during, and drying after development).


the CAMAG® HPTLC PRO Module PLATE STORAGE is part of the HPTLC PRO - Fully-automated sample analysis and evaluation for routine quality control. It is used to automate the execution of a sequence.


the CAMAG® HPTLC PRO SYSTEM consists of all CAMAG® HPTLC PRO Modules (order is important) and the software visionCATS connected to each other. The definition of the CAMAG® HPTLC PRO SYSTEM in visionCATS must match the way CAMAG® HPTLC PRO Modules are physically arranged.

CAMAG® Nanomat 4

the CAMAG® Nanomat 4 is a device for contact transfer application using capillaries.

CAMAG® TLC Plate Heater 3

the CAMAG® TLC Plate Heater 3 is a device to uniformly heat the plate, it is mostly used for post-chromatographic derivatization.

CAMAG® TLC Scanner 4

the CAMAG® TLC Scanner 4 is an instrument for scanning densitometry. A monochromatic light beam in form of a rectangle of adjustable size is moved across the individual tracks on the plate. The difference between the diffusely reflected light of the plate background and the absorbance or fluorescence behavior of the zones is measured.

CAMAG® Twin Trough Chamber

the CAMAG® Twin Trough Chamber is a glass tank with two compartments which reduce the amount of developing solvent required for development of a plate. While one trough is used for development the other may be used for saturating the chamber with developing solvent or another liquid.

CAMAG®certified product specialist

person trained and certified by CAMAG® to perform qualification and to support the customer at qualification related issues. The certificate has to be renewed every second year.


the carrier holds the plate on the conveyor of CAMAG® HPTLC PRO Modules.


a device in which the plate is developed (i.e. chromatography is performed). Depending on the separation task, the appropriate chamber can be a very simple glass tank or a highly sophisticated automatic developing instrument.

chamber target temperature

target temperature when performing the chamber temperature regulation.

chamber temperature

current temperature of the HPTLC PRO Module DEVELOPMENT chamber.

chamber temperature regulation (automatic or manual)

the HPTLC PRO Module DEVELOPMENT regulates the temperature of the development chamber from its current temperature to the target temperature.


the visual result of a separation, with different spots/bands or patterns corresponding to different components of the separated mixture.


is a separation technique using the different affinities of the components of a mixture to the stationary and the mobile phase of the chromatographic system. The distribution of the sample components between the two phases is based on adsorption -, partition-, ion exchange- or other criteria. While gas chromatography (mobile phase is a gas) is generally used to separate volatile molecules in the gas phase, liquid chromatography (liquid mobile phase) such as HPLC and planar chromatography will separate substances in solution.

clean plate correction

subtracts the image of the clean plate from images after chromatography. This procedure corrects the noise of the image and irregularities due to the plate structure. A cleaner, sharper image of the plate is the result.


automated process of removing of left over solvents or solutions from an instrument or module either subsequent to a step (cleaning) or before a step (pre-cleaning).

cleaning bottle

bottle assigned to the automated cleaning step.


used by Microsoft Windows programs as a temporary place to store information, pictures, graphics, etc. visionCATS supports this for all captured images (copy image to clipboard).

coefficient of variation

also called RSD (relative standard deviation), is the standard deviation of repeated measurements divided by the mean value of those measurements expressed in %.

comma-separated values

in computing, a comma-separated values (CSV) file is a delimited text file that uses a comma to separate values. A CSV file stores tabular data (numbers and text) in plain text. Each line of the file is a data record. Each record consists of one or more fields, separated by commas. The use of the comma as a field separator is the source of the name for this file format. For visionCATS the option “export of data” is available which allows the user to export “raw data” as .csv files.

comparison viewer

a comparison viewer file contains individual tracks from the same or different plates for side by side comparison. The file extension is .pcf.


a substance as part of a sample/mixture.


special feature of the CAMAG® HPTLC PRO Module DEVELOPMENT, which allows flow of a defined gas phase over the stationary phase during development.


consumables are products that consumers use recurrently, i.e., items which “get used up” by the process of using them or discarded. Therefore they do not fall under the regular warranty terms. CAMAG® HPTLC PRO Modules operate with a set of consumables such as bottle contents and rack contents

  • visionCATS documents consumables for all CAMAG devices.

  • visionCATS manages and check consumables for CAMAG® HPTLC PRO Modules only.


the transport unit in the front part of the CAMAG® HPTLC PRO Module:

conveyor manager

the software component belonging to the visionCATS server which:


the correlation coefficient describes a mathematical relationship between two data vectors. In visionCATS it is used to compare e.g. spectra. The correlation coefficient r = 1 describes a straight line. By comparing the correlation of a standard and an unknown, a statistical hypothesis on identity can be set up. By comparing the correlation of peak start to peak center with the correlation of peak center to peak end a statistical hypothesis on purity can be set up.

cut-off filter

is used to block or eliminate light below a certain wavelength, and preventing it from entering the detector.

data integrity

the degree to which a collection of data is complete, consistent, and accurate.

data resolution

the distance between two data points. In scanning densitometry (CAMAG® TLC Scanner 4) resolution of 25, 50, 100 or 200 µm can be selected. In image evaluation the resolution of the sensor and the quality of the optical system define the resolution. The CAMAG® Visualizer 2 can achieve a resolution of 82 µm.

data security

data security in terms of altering existing data as well as recovery of lost data and the respective traceability.

declaration of conformity

the declaration of conformity is a legal document issued by the manufacturer, demonstrating the fulfillment of the EU requirements relating to a product bearing the CE marking.


a process in which a substance or component is chemically changed to form degradation products.

degradation products

are impurities as results of degradation of substances.


a chemical reaction used to visualize the chromatogram. The derivatization reagent can be transferred onto the plate by spraying or immersion.


recording of the chromatogram (data acquisition) by scanning densitometry or capturing electronic images

detector mode

automatic or manual is used to describe how the detector is adjusted to the current light conditions and the region of interest.

deuterium lamp

a deuterium lamp is used in the CAMAG® TLC Scanner 4 as continuous light source with a wavelength in the range of 190 ~ 400 nm.

developing distance

distance from the lower edge of the plate to the solvent front.

developing solvent

is the solvent (or solvent mixture of known composition) that is placed into the developing chamber. The composition of the developing solvent changes during chamber saturation and chromatography due to interaction with the stationary phase and the gas phase in the chamber. Therefore, the composition of the mobile phase – the liquid moving through the stationary phase – can be different from the composition of the developing solvent.


is the step of actual chromatography, during which the mobile phase migrates through the layer on the plate (see also term planar chromatography).


a procedure in visionCATS to check the current condition of an instrument / software.


the process of decreasing the concentration of a component through addition of solvent.

dilution factor

the ratio of concentration of sample solution to stock solution.


term used for unit, e.g. volume (liter, milliliter, microliter, nanoliter), mass (gram, milligram, microgram, nanogram).

dual wavelength

a scan mode used by the CAMAG® TLC Scanner 4 to scan a plate at two different wavelengths. Both wavelengths can be subtracted from each other by using “profile subtraction”


in column chromatography the process of moving a substance through and out of the column. In Planar Chromatography the process of moving a substance off the application position.


in spectroscopy the release of light, e.g. from a lamp. Often used also in connection with fluorescence.

environmental specifications

set of specifications/conditions for the laboratory environment (humidity, ventilation, power supply etc.) required for proper installation/operation of the equipment.


the process of balancing the saturation level of the HPTLC/TLC layer by the mobile phase vapor prior to chromatography.


calculation of results, e.g. by means of polynomial regression via peak area.


in fluorescence spectroscopy the process in which a molecule absorbs a certain amount of energy (light of the excitation wavelength) to reach the excited state. Part of that energy is re-emitted as light of a longer wavelength (usually visible) if the molecule fluoresces.

excitation wavelength

in fluorescence spectroscopy the wavelength of light used for excitation.


a visionCATS function to send data to another visionCATS instrument or another software (e.g. excel) or to send graphics into other applications.

exposure time

the shutter opening time needed to capture an image.


the component within each CAMAG® HPTLC PRO Module, which moves the carrier between the feeding position on the conveyor (front), the park position, reference position and the processing position in each CAMAG® HPTLC PRO Module (rear).

feeding position

this refers to the position in the front of the conveyor of each CAMAG® HPTLC PRO Module, where the feeder fetches the carrier to feed it into the rear of each CAMAG® HPTLC PRO Module or unload it back to the conveyor.


the way the syringe of the CAMAG® Automatic TLC Sampler 4 (ATS 4) or the CAMAG® HPTLC PRO Module APPLICATION is filled and rinsed.


an electronic component, a mathematical formula or an optical instrument to refine or smooth the output. For example: an electronic filter is used to suppress electronic noise, a mathematical filter is used for smoothing data, an optical filter is applied to block, limit or reduce transmitted amount of light.


the electronic image of an HPTLC chromatogram (one track, including application position and front position), consisting of a sequence of (colored) zones. In HPTLC, fingerprints are qualified by the system suitability test (SST) on the same plate and can include information from different detection modes. HPTLC fingerprints can be converted into peak profiles from images (PPI) which resemble chromatograms generated by scanning densitometry (peak profiles from densitometry, PPD).

first track position X [mm]

the position of the very first application of the plate. The position is entered as distance in mm from the left plate edge to the center of the spot or band.

Flat Bottom Chamber

the CAMAG® Flat Bottom Chamber is a simple and inexpensive device for development.


light emission from a substance caused by electrons falling back from excited states in the shell. In the CAMAG® TLC Scanner 4 fluorescence is a scan-mode to measure the intensity based on the fluorescent behavior of the substances on an HPTLC plate.


electronic amplification

gas phase

the vapor phase in the developing chamber. The gas phase can heavily affect the chromatographic result (see also pre-conditioning).

Gaussian distribution (normal distribution)

a continuous distribution that is symmetrical around its mean. The mean, median, and mode of a Gaussian distribution are equal.

global settings

a set of parameter repeatedly used in visionCATS.


good laboratory practice / good manufacturing practice. Set of rules on how laboratory work is to be performed in order to get accepted by the regulatory agencies, e.g. FDA (Federal Drug Administration, USA).


a type of user management account in visionCATS. Guest users are limited to the root’s guest folder, therefore, they are unable to access any sensitive information in other visionCATS folders.

high dynamic range imaging

high dynamic range imaging (HDRI) is a technique used to reproduce a greater dynamic range of luminosity, more data in the shadows and highlights will be captured than for a standard dynamic range image. Several standard dynamic range images at different exposures are taken to capture shadows, normal and highlighted details. Then all these images are combined in one. In visionCATS, HDRI can only be taken for illumination under UV 366 nm (the other illuminations have a smaller dynamic range, which fits in a standard dynamic range image).

high-performance thin-layer chromatography

high-performance thin-layer chromatography (HPTLC) is the most advanced and reproducible form of planar chromatography. It is based on a standardized methodology, suitable instruments and software, and validated methods. HPTLC is described in the USP general chapter <203> and Ph. Eur. general chapter 2.8.25

HPTLC instrument

instruments which can be operated with visionCATS.

HPTLC PRO administrator

New visionCATS user role which can setup CAMAG® HPTLC PRO SYSTEM in the CAMAG® HPTLC PRO SYSTEM Configuration view.

HPTLC PRO maintenance tool

the tool installed together with the visionCATS HPTLC PRO instrument service. This tool gives direct access and full control of CAMAG® HPTLC PRO Modules connected to the computer.


new visionCATS user role defining the ability to trigger the execution of sequences in the CAMAG® HPTLC PRO SYSTEM in system mode after having prepared all the necessary consumables.


a set of characteristics by which two or more substances are recognizable as identical. Identity of a substance can be established by comparison to a reference standard taking into account the position (same RF values), spectral information (same spectra and/or color), and behavior during derivatization. For identification of complex and variable multicomponent mixtures such as herbal drugs, the entire chromatogram (fingerprint) is considered and evaluated against a set of acceptance criteria defined by a (pharmacopoeial) monograph.


or dipping is a technique used for reagent transfer onto plates.

installation qualification

is a procedure performed at the site and time of installation with the purpose of being able to use the instrument under the regulations of GLP/GMP. The IQ procedure verifies and documents that all key aspects of the installation comply with the manufacturer’s specifications, codes, safety and design parameters. In order to qualify for a CAMAG IQ certificate, this procedure has to be performed by a CAMAG®certified product specialist.


in chromatography used for peak detection, i.e. the procedure of finding peaks and calculating the height and area of those peaks. During integration the raw data are filtered, the baseline is established, peaks are detected, and height and area of each peak is calculated.

integration end

the position (RF) where the peak detection terminates.

integration start

the position (RF) where the peak detection starts.

license key

license file for the system, including all devices and options, which is required to enable these functionalities in the visionCATS software.

linear regression

the mathematical function describing the straight line that best fits a set of x/y values (e.g. standard amounts vs. measured values). 5 standard levels are recommended for linear regression (see also regression).


the CAMAG® Linomat 5 is a semi-automated instrument for application of samples as narrow bands or spots using the spray-on technique.

liquid chromatography

a separation technique in which the mobile phase is a liquid. Liquid chromatography can be performed in a column or on a plate.

locked evaluation

an evaluation with locked results is available in read only mode.


Limit Of Detection is the lowest amount of analyte in a sample that can be detected, but not necessarily quantitated; under the stated experimental conditions.


when starting visionCATS each user should login with a user name for visionCATS to recognize the user.


Limit Of Quantification is the lowest amount of analyte in a sample that can be determined with acceptable precision and accuracy under the stated experimental conditions.

lowest slope

a way how the integration routine draws the baseline (baseline correction)


relative luminance follows the photometric definition of luminance, but with the values normalized to 1 for a reference white. (L=1/3R+1/3G+1/3B)

a calculation routine offered by visionCATS to calculate the amount of impurities and/or degradation products (related substances) by means of the main substance – if standardized reference substances are not available. Usually it is used for calculating the amount or % of impurities within the product (main substance).

manual loading position

if the CAMAG® HPTLC PRO Module or CAMAG® HPTLC PRO SYSTEM is run without the CAMAG® HPTLC PRO Module PLATE STORAGE, the carrier transporting the HPTLC plates has to be inserted into the CAMAG® HPTLC PRO SYSTEM manually. The manual loading position is located on the left hand side of the CAMAG® HPTLC PRO Module or the CAMAG® HPTLC PRO SYSTEM.

manual unloading position

if the CAMAG® HPTLC PRO Module or SYSTEM is run without the CAMAG® HPTLC PRO Module PLATE STORAGE, the carrier transporting the HPTLC plates has to be removed from the SYSTEM manually. The manual unloading position is located on the right hand side of the module or the System.

mass spectrometry

a technique used for qualitative and quantitative analysis of chemicals in a sample by measuring the mass-to-charge ratio and extent of gas-phase ions.


components within the sample besides the analyte(s). Matrix can cause changes in the chromatographic results, e.g. shifted RF values or different signal response (matrix effects)

mercury lamp

a high power light source based on ionization of mercury vapor.


a method is a set of parameters required to perform an analytical task. In visionCATS the file containing parameters only is called method and has the file extension .pmf.

metric position (mm)

the metric position from the lower edge of the plate to the center of the separated zone can be displayed instead of the RF value.


a regression mode in visionCATS applicable for a wide concentration range (saturation curve). It is usually used during method development as a starting point. In the next step the working range is determined and adjusted to a smaller concentration range. For quantification, the linear working range is recommended.

migration distance

the distance (relative to the application position) a zone has moved during chromatography. See also retardation factor and metric position.

mobile phase

the mobile phase is the solvent or solvent mixture migrating through the stationary phase during development.


a device that separates incoming light into a spectrum of individual wavelengths. A range (see bandwidth) can be selected for densitometry. The mid wavelength of this range is called the measuring wavelength and the resulting light is called monochromatic.


Transport of a carrier between any given defined position within a CAMAG® HPTLC PRO Module or a CAMAG® HPTLC PRO SYSTEM.

A run is divided into several moves. Each move consists in:

  • Loading the carrier for the first move, or unparking from previous CAMAG® HPTLC PRO Module for subsequent moves

  • Moving the carrier though the conveyors (to the left or to the right) until reaching the unpark position of the step’s CAMAG® HPTLC PRO Module being executed by the move

  • Parking the carrier

  • Executing the step associated with the move

  • For the last move only, unparking and moving the carrier to the last CAMAG® HPTLC PRO Module of the line and ejecting it

multi level calibration

is a calibration mode using standards of different concentrations of which the same volume is applied (or one standard concentration applied at different volume).

multi-wavelength scan

multi-wavelength scan is a detection mode of the CAMAG® TLC Scanner 4 to scan a plate at several selected wavelengths in one step (one after the other).


random signal produced by any electronic equipment as well as the structure of the HPTLC/TLC layer.

normal-phase chromatography

a development method used in chromatography in which the stationary phase is more polar than the mobile phase.

nozzle (application)

the spraying outlet used for the syringe in the CAMAG® Linomat 5 and CAMAG® Automatic TLC Sampler 4 (ATS 4). The used gas (compressed air or N2) passes through this nozzle, nebulizes the sample into a fine spray and applies it onto the plate as narrow bands or small spots.

nozzle (derivatization)

to meet the divergent physicochemical properties, four color-coded nozzles are available for the CAMAG® Derivatizer. The information about the selected nozzle and spraying level can be entered in the instrument step in the visionCATS method/analysis file.

number of tracks

indicates the number of applications on a plate, according to the track assignment.


electronic procedure to shift the detector zero point.

operation qualification

is a procedure at customers site with the purpose of being able to use the instrument under the regulation of GLP/GMP. The OQ procedure verifies and documents that the instrument performs according to the manufacturer’s specification at the customer’s site. This qualification is performed subsequent to installation and is repeated at certain intervals recommended by the manufacturer or defined by the customer. In order to qualify for a CAMAG® OQ Certificate, this procedure has to be performed by a CAMAG®certified product specialist.


application of two or more samples (from different vials) consecutively onto the same position on the plate. Overspotting can be used for spiking a sample, pre-chromatographic derivatization, etc.

park position

refers to the position inside of each CAMAG® HPTLC PRO Module, where the conveyor manager temporarily parks a carrier to let pass other carriers on the conveyor. When the conveyor manager parks a carrier, the feeder of the CAMAG® HPTLC PRO Module moves the carrier inside the instrument. The carrier is then in park position. The park position is the starting point of the execution of a step by the instrument. Once in park position, the module is ready to move the conveyor if another carrier must go through the instrument.

partition chromatography

a separation method that is based on differences between the solubilities of the sample components in the stationary phase (gas chromatography), or on differences between the solubilities of the components in the mobile and stationary phases (liquid chromatography).


part of the measured analog curve corresponding to a fraction on the plate. The peak detection level is usually defined as a “significant deviation” of the signal from the baseline (typically at least 2-3 times the background noise level). Peaks are detected during integration.

peak area

sum of all data values between peak start and end.

peak height

“vertical” distance in AU between the baseline and the peak maximum.

peak profile from densitometry

densitogram, plot of the Scanner signal obtained from a track against the RF value.

peak profile from image

chromatogram (analog curve) generated from electronic images by plotting the luminance calculated from the RGB values of pixels per line of the track against their RF values ( L = 1/3 R + 1/3 G + 1/3 B)

peak purity

value of the quality of the purity of a chemical substance. By purity scanning (spectrum scan of three points within a peak) co-eluting substances can be detected.

peak resolution

the separation of two peaks in terms of their average peak width at base

peak window

a distance (∆RF required) in direction of chromatography within which peaks are identified (assigned) as belonging to the same component (substance).

photo-multiplier (PM)

instrument consisting of a photo-voltaic cell and an amplifier. The PM converts light (amount of photons) into a current.

planar chromatography

a separation technique in which the stationary phase is a flat surface. This can be a paper (paper chromatography), or a layer of solid particles spread on a support, such as a glass plate (thin-layer chromatography).


actually, the carrier of the stationary phase, made from glass, aluminium, or plastic. Also a general expression for the stationary phase. In HPTLC, a 20x10 cm glass plate coated with a 200 µm layer of 2-10 µm irregular particles of silica gel 60 with an F 254 indicator is generally used. A polymeric binder is used in manufacturing such plates.

plate format

dimension of a plate, e.g. 20 x 10 cm for a standard HPTLC plate. The first measure is for the horizontal edge (X-direction on the plate).

plate layout

in visionCATS: a display showing the application pattern for a plate, also tab that includes information about the stationary phase, plate size, geometry of applied zones and solvent front position

polynomial regression

a mathematical function describing the curved line that best fits a set of x/y values (e.g. standard amounts vs. measured values). 4 to 5 standard levels are required for polynomial regression (see also regression).

pre-chromatographic derivatization

derivatization before development during sample preparation or by overspotting of the sample tracks with the reagent.


pre-loading of the stationary phase with molecules from the gas phase (water, solvent, acid, base) prior to development. Pre-conditioning may be utilized to affect the chromatographic result and to reduce the formation of secondary fronts. Pre-conditioning (with water molecules) at a defined relative humidity see activation.


the time any loaded plate is processed in the module (e.g. samples are applied, plate is developed or derivatized etc.).

processing position

the effective position of the carrier during the processing of the plate, which may differ between modules.

profile subtraction

a feature that allows to subtract the profile obtained from a single track from those of all other tracks or to subtract the profiles measured at one wavelength from that measured at another wavelength (dual wavelength scan)

pump power

in % nominal pump power (CAMAG® HPTLC PRO Module DEVELOPMENT)

purity scan

a spectrum scan mode to determine the peak purity. Spectra are scanned in both peak flanks and at the maximum of the peak (maximum height).


a certificate of suitability which demonstrates that equipment is working properly and is actually producing the expected results. It is usually a multi-stage process consisting of design qualification (DQ), installation qualification (IQ) and operational qualification (OQ).


determination of the amount of a given substance in a sample.

quick scan

a technique used for the CAMAG® TLC Scanner 4 to automatically adjust the PM to the optimum gain and sensitivity. In manual mode a selected track and region of interest can be selected for PM adjustment, useful for trace analysis.


a holding device in which the sample vials can be placed. The standard rack for the CAMAG® Automatic TLC Sampler 4 (ATS 4) holds up to 66 sample vials. The standard rack for the CAMAG® HPTLC PRO Module APPLICATION holds up to 75 vials.

raw data

unprocessed numerical information (data) produced by an analytical measuring system. According to GLP/GMP all raw data must be available – the definition of “raw data” is thus a little different between manufacturers of analytical instruments. In visionCATS all data acquired during analysis is saved as raw data.

reference amount

the amount of sample the result is to be given for, e.g. the average weight of a tablet.

reference spectrum

the lamp and plate material spectrum measured before and then subtracted from the actual spectrum recorded from a zone. This spectrum is used for scaling the measured spectrum properly.

regression mode

also called “least squares fit” is a procedure approximating a series of data points by means of a curve. visionCATS uses a linear, polynomial or Michaelis-Menten regression to calculate the results.

report defaults

customer settings for including/excluding parts of the report.

a heading logo on the report, which represents the user’s company / laboratory.

report template

saved report settings that can be reused in different analysis


a carrier is identified by its RFID tag when it reaches the feeding position on the conveyor.


the run represents a set of automated steps to execute for a given analysis in a given CAMAG® HPTLC PRO SYSTEM. If an analysis contains CAMAG® HPTLC/TLC and CAMAG® HPTLC PRO steps, the software allows to execute the CAMAG® HPTLC/TLC steps, until the first CAMAG® HPTLC PRO steps are reached. Then the user will have to add these steps to a sequence and execute it to be able to perform the next manual CAMAG® HPTLC/TLC steps.

S/N ratio

is the signal to noise ratio.

sample ID (vial ID)

identification (text or number) of the unknown sample(s)

sample solvent type (application step)

the closest default for the solvent, in which the samples are dissolved. Based on the solvent type (viscosity and volatility), the dosage speed for the application instrument is set.


equilibration of the gas phase in a closed chamber with the vapor of the developing solvent.


a measurement performed by the CAMAG® TLC Scanner 4. During the scan the plate is moved beneath the light beam in a pattern suitable for measuring all tracks of the plate.

scanning speed

the speed of moving the plate underneath the light beam in the CAMAG® TLC Scanner 4.


in analysis the degree of change in the measured value (AU) in response to a change of the measured property, usually mass.


the runs added to a CAMAG® HPTLC PRO SYSTEM are grouped into sequences. The runs placed in the same sequence are compatible in term of consumables and there are up to 5 runs pro sequence.

serial number

the serial number of the visionCATS license is the Product ID shown in the “about visionCATS” dialog, the SN of the instrument is on the rating plate.

single wavelength

a scan mode used by the CAMAG® TLC Scanner 4 to scan a plate at one selected wavelength.


the light beam, used to illuminate the measuring position on the plate with monochromatic light during measurement with the CAMAG® TLC Scanner 4.

slit length

the length of the light beam. For samples applied as bands the slit length should be between 50-80% of the band length. For samples applied as spots the slit length should be larger than the width of the largest spot (120% recommended).

slit size

length and width of the light beam.

slit width

the width of the light beam. For HPTLC applications a slit width of 0.2 mm is commonly used for best S/N ratio.

solvent front

the leading edge of the mobile phase as it travels along the stationary phase. The position is measured in mm relative to the lower edge of the plate (see also alpha -front)

spectrum comparison

a visionCATS feature used to save and compare spectra recorded on tracks from the same or different plates.

spectrum correlation

calculation of the correlation coefficient of spectra on different tracks (identity) and/or within the same peak (purity).

spectrum scan

spectrum scan is a scan mode of the CAMAG® TLC Scanner 4 used to obtain a spectrum from zones on the plate.


addition of a substance to an already available amount of the same substance. If only standards are concerned the procedure is usually called “standard addition”.

spot (application type)

an application type, in which the sample is applied to the plate in form of spots by the spray-on or contact technique.

spraying level

setting for CAMAG® Derivatizer


the container of up to 5 carriers. The CAMAG® HPTLC PRO Module PLATE STORAGE contains two stackers. One for the clean plates and one for the processed plates. When adding a run to a sequence, the user has to define whether the plate is clean. This will determine in which stacker to place it. When a run is finished, the carrier is always placed into the processed stacker.

standard for error correction

substance of known amount available on each track against which all other substances on the same track are quantified.

stationary phase

is the thin-layer of particles on the plate, which separate the sample during chromatography. HPTLC Silica 60 F254 coated onto 20x10 cm glass plates is the most widely used stationary phase for HPTLC.

substance assignment

a routine in visionCATS used to link a zone on the plate to a substance in the substance table. Substance assignment is performed based on the RF position and peak window entered in the substance table.

substance name

name of a substance, is unique for the whole analysis.

substance table

contains the input fields for the substance(s) like substance name, concentration, and purity.


used in the application devices to apply defined volumes of sample solutions onto plates.

system suitability test

test to evaluate, whether the results of an analysis meet certain criteria such as minimum resolution of two peak, detectability of analyte at the LOD, reproducibility of RF . In HPTLC the test is required to ensure plate to plate comparability of results.


limit, at which the peak detection routine decides to use or discard a peak.

TLC Visualizer
CAMAG® TLC Visualizer
CAMAG® TLC Visualizer 2
CAMAG® TLC Visualizer 3

the CAMAG® TLC Visualizer is a high-end imaging and documentation instrument for TLC/HPTLC plates. Three different illuminations (UV 254 nm, UV 366 nm, and white light) are available. The generic term TLC Visualizer is used in the software when it could cover any version of the instrument.

track assignment

describes the relation between tracks and samples/standards applied. The track assignment is a separate part of the analysis file and affects the application and the evaluation step.

track distance

is the distance measured from center to center of two neighboring tracks.

track subtraction

a feature that allows to subtract the profile obtained from a single track from those of all other tracks


area of the plate that corresponds to the chromatogram of a sample, reference, or a blank.

ultraviolet light

electromagnetic radiation with a wavelength of 10 nm to 400 nm, which is shorter than that of visible light but longer than X-rays.

view angle

the viewing or display angle of the 3D view. This angle can be changed by dragging with the mouse while holding the <CTRL> key.

visible light

electromagnetic radiation with a wavelength of 400 nm to 800 nm


CAMAG® HPTLC software visionCATS is the most advanced software for HPTLC analysis. Based on a state-of-the-art three-tier architecture, visionCATS can either be run on a single workstation or in a multi-user lab network. The software organizes the workflow of HPTLC, controls the involved CAMAG® instruments, and manages the data.

visionCATS client installation

visionCATS client installation without server.

visionCATS cluster

a visionCATS installation including the server and all connected clients and instruments.

visionCATS evaluation

interpretation and documentation of acquired data by visionCATS.

visionCATS full installation

visionCATS client and server on one PC.

visionCATS HPTLC instrument service

a windows service responsible for the communication with CAMAG® instruments RS232 supported under visionCATS.

visionCATS HPTLC PRO instrument service

CAMAG® HPTLC instruments communicate with visionCATS through the visionCATS HPTLC instrument service whereas CAMAG® HPTLC PRO Modules communicate with visionCATS through the new visionCATS HPTLC PRO instrument service. The visionCATS HPTLC PRO instrument service detects and establishes USB connections with the CAMAG® HPTLC PRO Modules. It executes requests coming from the conveyor manager and gives feedback. The visionCATS HPTLC PRO instrument service is installed by the visionCATS installer.

visionCATS server installation

visionCATS server installation without client.


according the CAMAG® homepage: We warrant to you that title to all products sold to you is good and the transfer rightful, subject to the paragraph entitled “contingencies.” We warrant to you that each product manufactured by or for us will be free from defects in material and workmanship in normal use and service for two (2) years from the date of delivery to you as the original purchaser, if used according to the user manual delivered with CAMAG® products.


the X-direction on the plate is the direction perpendicular to the direction of chromatography. X positions represent the positions of different tracks on the plate.


the offset line of the detector is usually referenced as the zero line although the offset level does not correspond to the AD (analog-digital converter) value 0. The scaling of the data values to the analog offset of the curve or zero line is done at display time.


acceptable range for a peak maximum to be located at.

retardation factor
the relative distance the substance has migrated compared to the distance the solvent front has migrated.

𝑅ꜰ = (peak position – application position) / (solvent front position – application position).

𝑅ꜰ tool

a tool to show the 𝑅ꜰ value of zones on the digital image.