0 adjust

see Zero adjust


or single wavelength is a scan mode used by the HPTLC Scanner 3 to scan an HPTLC/TLC plate with one selected wavelength.


or dual wavelength is a scan mode used by the HPTLC Scanner 3 to scan an HPTLC/TLC plate with two different wavelengths.


FDA 21 CFR Part 11: Requirements for Electronic Records and Electronic Signatures


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

2D chromatography

a square HPTLC/TLC is first chromatographed in one direction and afterward turned 90° and chromatographed for a second time


a three-dimensional representation of geometric data.


in visionCATS: refers to the amount and/or concentration of a component available for calibration on the plate.


is a scan-mode of the HPTLC Scanner 3 to determine the amount of a substance on an HPTLC plate as difference in absorption between the empty HPTLC plate and the signal of the fraction on that plate.


in physics is the take-up of light, heat, or other radiant energy by molecules. Absorption in chemistry is the penetration of one substance into another. For example, a gas such as oxygen may be absorbed (dissolved) in water.


Automatic Developing Chamber is a fully automatic developing chamber for HPTLC/TLC plates using the standard Twin Trough Chamber allowing an easy transfer of existing methods. A CCD monitors the solvent front and the separation is terminated when the front has reached the pre-set distance. The HPTLC/TLC plate is dried afterwards with high speed cold air. The option humidity control allows controlling of the most important environmental condition.


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 substance in a fraction (weight, volume, %, ppm, etc.).

Analog offset

the value of the AD converter that represents the measurement at the zeroing position. Unless this value is set to zero, the range below the offset value allows the AD converter the 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 HPTLC/TLC 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.


An unknown substance in a sample, which needs to be measured, determined or quantified.


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


camera lens opening mostly expressed in F-Stops. (F16, F11, F8, F5.6, F4.0, F3.5, F2.8)


Dosing a certain sample volume onto the HPTLC/TLC layer.

Application mode

indicates how the samples are applied e.g. spotwise, bandwise or rectangular

Application pattern

the application geometry of the samples of an HPTLC/TLC plate (see also Sequence)

Application position

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

Application sequence

describes the relation between tracks and samples/standards applied. The sequence is defined at sample application and used during for evaluation (see also Sequence)

Application volume

the volume in μL or nL, which will be applied onto the HPTLC/TLC plate


the sum of all data values between peak start and peak end.


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

Assign a substance

Assigning a peak to a substance window means the peak in question will be given the name of the substance (and all other properties available in the Substance dialog).


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


In HPTLC/TLC the signal from the untreated or derivatized plate that does not contain sample.

Background subtraction

a mathematical procedure to subtract the background data.

Band application

Samples are applied onto the HPTLC/TLC plate in form of narrow bands of defined length by the spray-on technique.

Band length

length of the applied band in X-direction in mm.

Band width

with the ATS4 the spray-on technique also allows sample application in form or rectangles. In this case band width defines the dimension of the applied area in y-direction.


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

The HPTLC Scanner 3 can use a bandwidth of 20 or 5nm. The 5nm setting is mostly used for the spectrum scan mode.

Bandwise application

see Band application.


a series of lines of different thickness representing numbers. This code is read and translated by a barcode reader, e.g. for identification of a product or sample.

Barcode reader

a device to read barcodes.


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 slopes”, a routine developed for HPTLC measurements where the plate background is an important factor during detection.

Baseline marker

is a graphical tool to show the position of the baseline. During Video-Integration visionCATS allows to add, eliminate, and move baseline markers and thus to influence the way of integration.


mostly a number to identify a production lot.

Bitmap or .bmp

a file format used to store graphic information. Images captured with a digital or video camera can be exported in this format.

Blank track

an empty track or a track running only matrix is used for ‘blank track’-type background subtraction. Blank track subtraction is useful to eliminate irregularities in the background, e.g. from secondary fronts.

Blind sample

a sample without an analyte.


is used in quantitative HPTLC/TLC relate the measured signal from a given standard substance on the plate to the amount of substance present.

Calibration curve

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

Calibration mode

offers a selection of different calculation modes for quantitative HPTLC/TLC evaluation. Available are reproducibility (which is not really a calibration mode), single level calibration, and multi level calibration via linear, polynomial or Michaelis-Menten regression.

CAMAG Linomat 5

a devise for application of samples as narrow bands onto an HPTLC/TLC plate by means of the spray-on technique.

Camera settings

parameters required to capture an image.


a Charge Coupled Device is normally used for light detection. With a CCD images can be captured and the signal can be transferred in analog or digital form for further processing.


a device in which the HPTLC/TLC plate is developed (or chromatographed). Depending on the separation task, the appropriate chamber can be a very simple glass tank or a highly sophisticated automatic developing device.

Chamber type

type of device used for chromatography. The selection offers flat bottom glass tanks, twin trough glass tanks, horizontal chambers etc.


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 evaporated molecules in the gas phase, liquid chromatography (liquid mobile phase) such as HPLC and Planar Chromatography will separate substances in solution.

Clean Plate Correction

lets you subtract an image of the clean plate from images after chromatography. There is already some structure on the plate before chromatography (like background noise in an audio recording). The subtraction will result in a cleaner, sharpened image of the plate.


used by Microsoft Window programs as a temporary place to store information, pictures, graphics, etc.

Coef. of Variance (CV)

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


a comparison contains individual tracks from the same or different plates to permits a side-by-side comparison. The file extension is .pcf.

Compartment Illumination

is a UV lamp located inside the Scanner measuring compartment and used to illuminate the HPTLC/TLC plate with 254nm UV light. Compartment illumination is used to locate (see) substances quenching the UV indicator on the plate.


used in photography to compensate for backlight situations.


a substance as part of a mixture.


application of pressure to the liquid inside the syringe / capillary in order to dissolve small gas bubbles or to check leaks.

Compression time

time of compression of liquid inside the capillary in seconds.

Compression volume

volume by which the liquid in the capillary is compressed to dissolve possible gas bubbles in the solvent or sample.

Computer Science

Numerical or other information represented in a form suitable for processing by computer.


adjustment of the chromatographic properties of the stationary phase in HPTLC/TLC through exposure to a defined gas phase (relative humidity, solvent composition, etc.).

Confidence Interval (CI)

is calculated as a function of standard deviation of the calibration, standard deviation of the analysis and the error probability. The ci values reported are relative, i.e. divided by the result and expressed in %.


pre-arrangement of parts and/or elements for proper operation.

Contact transfer needle

is used with an ATS4 syringe to apply spots onto the HPTLC/TLC plate by contact.

Content Uniformity Test

is a test procedure described in USP/EuPh. etc. describing a procedure to assure the uniformity within a production batch.

Correlation (r)

the correlation coefficient describes a mathematical relationship between two data vectors. In visionCATS it is used to compare e.g. spectra. If the correlation coefficient r = 1 the coefficient describes a straight line.

By comparing the correlation of two standards with the correlation of a standard to 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.

Comma-separated values

A comma-separated values (CSV) (also sometimes called character-separated values, because the separator character does not have to be a comma) file stores tabular data (numbers and text) in plain-text form. Plain text means that the file is a sequence of characters, with no data that has to be interpreted instead, as binary numbers. A CSV file consists of any number of records, separated by line breaks of some kind; each record consists of fields, separated by some other character or string, most commonly a literal comma or tab. Usually, all records have an identical sequence of fields.

Comma-separated values. (2014, July 23). In Wikipedia, The Free Encyclopedia. Retrieved 08:11, July 30, 2014, from

Cut-off filter

is used to block or eliminate light below a certain wavelength entering the detector, photo- or video camera.

D2 lamp

a Deuterium lamp is used in the HPTLC Scanner 3 as continuous light source with a wavelength in the range of 190 ~ 400 nm.


Factual information, especially information organized for analysis or used to reason or make decisions. Values derived from scientific or analytical experiments.

Data resolution

the distance between two measured values during scan. With HPTLC Scanner 3 this resolution can be selected 25/50/100 and 200µm. For HPTLC plates 100µm and for HPTLC plates 200µm is usually recommended.

Declaration of conformity

see visionCATS support of GLP / GMP


a particular value for a variable automatically assigned by the system.


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.


originally a device or instrument to determine the degree of darkening of photographic film or other semitransparent objects. Modern densitometers use powerful light source and a photomultiplier (PM).

The CAMAG HPTLC Scanner 3 determines the amount of a substance on an HPTLC plate as a function of the difference in amount of light reflected/emitted from the substance on the plate and the light reflected/emitted from the empty plate. A plot of the resulting signal against the migration distance yields an analog curve of the chromatogram, which can be integrated to report results as peak area, peak height, area% and height%.


a chemical reaction used to visualize the separated fractions. The derivatization reagent required for a specific chemical reaction can be applied to the HPTLC/TLC by spraying or by plate immersion.

Design Qualification

verifies that the rigorous specifications and design review methods defined in the Quality Management System of the manufacturer have been followed.

CAMAG’s ISO 9000 certified Quality Management System ascertains defined testing procedures, error reporting and controlled updating of documents. Compliance is documented, e.g. by the “Declaration of System Validation” and “Declaration of Conformity” supplied with specific products.

“Design Qualification” is sometimes used with a different meaning, e. g. it may be confused with “suitability of the laboratory equipment for a specific task”.


measurement of the object, e.g. using an HPTLC Scanner

Detector mode

AUTOMATIC or MANUAL is used to describe how the detector is adjusted to the current light conditions.

Developing Solvent

in Planar Chromatography commonly used as synonym for the mobile phase. However, developing solvent is actually the liquid (mixture of liquids) that is placed into the developing chamber. The composition of the developing solvent changes during chromatography due to interaction with the stationary phase and 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 in HPTLC/TLC during which the mobile phase (developing solvent/eluent) is moving through the layer. (See also Planar-Chromatography)

Deviation [%]

in visionCATS the “permitted deviation” is the extension of the calibration curve on both ends by a given percentage.


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), weight (gram, milligram, microgram, nanogram).

Dimetric projection

In dimetric projection, the direction of viewing is such that two of the three axes of space appear equally foreshortened, of which the attendant scale and angles of presentation are determined according to the angle of viewing; the scale of the third direction (vertical) is determined separately.

ometric projection. (2014, May 12). In Wikipedia, The Free Encyclopedia. Retrieved 07:21, July 30, 2014, from


Device such as computer screen to show information or data.

Display scaling

the value entered as display scaling will determine the value of the vertical display axis (AU). Normal setting is 1000 AU - a lower value will increase the height of the measured signal (peaks) on the monitor.

Distance between tracks

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

Drying device

equipment used to dry the HPTLC/TLC plate after pre-washing, after chromatography or after derivatization.


synonym for mobile phase.


in column chromatography the process of moving a substance through and out of the column. Also used as synonym for chromatography. In planar chromatography the process of moving a substance off the application position. Also, incorrectly, used as synonym for development.


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

Emission wavelength

the wavelength of the emitted light.

Environmental specs

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


Mathematics: the error is the difference between an observed (i.e. computed or measured) value and the true value.

Error propagation

Mathematics: the rules for treating the error of individual values during mathematical operations.


calculation of results, e.g. by means of polynomial regression for peak-height.


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 wavelength of the light that causes the excitation.


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

Exposure time

the shutter opening time needed to capture an image.


an electronic component, a mathematical formula or an optical device 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.

First application pos.

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


light emission from a substance caused by electrons falling back from excited states in the shell.

in the HPTLC Scanner 3 fluorescence is a scan-mode to measure the intensity based on the fluorescent behavior of the substances on an HPTLC plate.

Filling quality

the way the ATS4 syringe is rinsed and filled when shifting to another sample.


electronic amplification.

Gas phase

the vapor phase in the developing chamber. The gas phase can heavily affect the chromatographic result. See also Conditioning.

Glass sprayer

a simple and inexpensive device to apply the derivatization reagent to the HPTLC/TLC plate.

Glass tank

a simple and inexpensive device for development of HPTLC/TLC plates.

Global defaults

standard setting required for daily use of visionCATS, e.g. stationary phases, solvent names, etc.

Global settings

a set of parameter repeatedly used in visionCATS.

GLP Code

a unique code added to some Merck HPTLC plates to positively identify this specific plate


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, i.e. FDA (Federal Drug Administration, USA).

Grey filter

is used in the HPTLC Scanner 3 with transmission measurements to reduce excessive light.


a type of User Management account in visionCATS. Guest users are limited to the root’s Guest folder, therefore, it prevents them from accessing to any sensitive information you may have in other visionCATS folders.

Hair dryer

may be used to dry an HPTLC/TLC plate after development.


High-dynamic-range imaging 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 images can only be made for R366 illumination (the other illuminations have a smaller dynamic-range, which fit in a standard-dynamic-range image).


the height of a single peak as percentage of the total height of all peaks on one specific track.

Hg lamp

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

Holographic grid

as an alternative to a prism used in the monochromator (TLC Scanner 3) to break up the incoming light into a spectrum.


uniformly, evenly distributed.

Horizontal chamber

a separation device in which the HPTLC/TLC plate is developed horizontally.


High Performance Thin Layer Chromatography, new name Planar Chromatography.


HPTLC plate coated with Silica Gel of smaller and more homogenous particle size (main fraction of distribution within 5-7µm) and thinner layer (200µm).

This plate type allows higher separation performance and requires application of lower amounts of sample.


device for spraying on reagents onto the layer, e.g. for derivatization reactions.


a set of characteristics by which two or more substance are recognizable as identical. In HPTLC/TLC two criteria need to be fulfilled for a positive identification, i.e. same migration distance (or RF) and same spectra.

Image size

the size of the electronically captured image, mostly expressed in number of pixels (e.g. 1024 x 768 pixels)


or dipping technique used to apply the derivatization reagent to an HPTLC/TLC plate. Immersion is preferred over spraying since the layer is more uniformly coated with the derivatization reagent.

Immersion device

is used for reproducible application of the derivatization reagent.

Instrument Service

a Windows service responsible for the communication with CAMAG instruments


a check box in the Scanner sequence table to select if a track should be integrated or not.


in chromatography used for peak detection, i.e. the procedure of finding peaks and calculating the height and area of these peaks.

During integration the raw data is filtered, the baseline is established, peaks are detected, and height and area of each peak is calculated.

Integration end

the position (MD or RF) where the peak detection terminates.

Integration start

the position (MD or RF) where the peak detection starts.

Internal standard

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

Installation Qualification

or IQ 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 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 is to be performed by a Product Specialist, certified by CAMAG.


International Standard organization.

In case of photography (incl. digital cameras) the term ISO is used for film speed. Higher values represent higher film speed and at the same time, more grain in the image.

Isometric projection

Isometric projection is a method for visually representing three-dimensional objects in two dimensions in technical and engineering drawings. It is an axonometric projection in which the three coordinate axes appear equally foreshortened and the angles between any two of them are 120 degrees.

Isometric projection. (2014, July 23). In Wikipedia, The Free Encyclopedia. Retrieved 07:06, July 30, 2014, from


the two scientists who formulated the mathematical expression on light scattering in solid materials.

Luminance (relative)

Relative luminance follows the photometric definition of luminance, but with the values normalized to 1 for a reference white.


a source for light. The HPTLC Scanner uses D2, W and Hg lamps.

Layer Modification

changing the properties of the HPTLC/TLC for a special analytical task (e.g. by impregnating).


in visionCATS: a display showing how the samples are applied to the HPTLC/TLC plate

License Key

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

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). 3 to 4 standard levels are required for linear regression. See also Regression.

Locked evaluation

an evaluation which results are locked, therefore setting the evaluation in read-only mode.


Limit of detection, the lowest amount of a substance, which the detection device, e.g. HPTLC Scanner, can detect.


when starting visionCATS each user should login with his/her user name in order to let visionCATS recognize the user.


for switching of user, a logout is needed.


Limit of quantification is the lowest amount, which can be used for quantification. Generally the LOQ is 2~4 times LOD.

Lowest slope

a way how the integration routine draws the baseline

a calculation routine offered by the 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.

USP/EuroPh uses the name “related compounds” and specifies that the weight sum of all there compounds may not pass 2% of the amount of the main substance.


the producer of the HPTLC/TLC plates / solvents / reagents etc.


the blank space at the top, bottom, left and right of a printed page.


indicates which type of stationary phase was used for plate coating.


inactive components of the sample used to add volume or stability.

Measuring mode

the way how the Scanner measures the signal from the HPTLC/TLC plate. Commonly used are absorption or fluorescence modes.

Measuring PM

photo-multiplier, which picks-up the signal reflected by the HPTLC/TLC plate or measuring object. In the HPTLC Scanner 3 the sensitivity of the measuring PM is automatically controlled by the reference PM.


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


10 -3 gram


two scientists who formulated the saturation curve.

In visionCATS there are two regression curves based on the Michaelis-Menten theory available: the ‘normal saturation curve’ through the origin, also called Michaelis-Menten1 and the ‘optimizing saturation curve’ which is not forced through the origin, also called Michaelis-Menten 2.

Migration Distance (MD)

migration distance is measured from the lower edge of the HPTLC/TLC plate to the center of the separated fraction.


10 -3 liter

Mobile phase

the mobile phase is the solvent or solvent mixture moving through the stationary phase on the HPTLC/TLC plate during development.


a device that separates incoming light into a spectrum of individual wavelength. 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.

Multi level calibration

is a ‘wide range’ calibration mode using standards of several different levels (amounts).


10 -3 volt


multi wavelength is a scan mode used by the HPTLC Scanner 3 to scan an HPTLC/TLC plate with several individually selected wavelengths (one after the other).


a manually operated device for spotwise sample application.

ng (nanogram)

10 -9 gram


an inert gas required for running several CAMAG instruments.

nL (nanoliter)

10 -9 liter

nm (nanometer)

10 -9 meter


random signal produced by any electronic equipment.


comments, explanation, observation and/or notice in brief written format


the spraying outlet used on the Linomat 5 and ATS4. The inert gas - mostly N2 - will pass through this nozzle and will nebulize the sample in to a fine spray and apply it to the HPTLC/TLC plates in form of narrow bands.

Nozzle temperature
the temperature at which the nozzle is operated. Selection is possible for 30 / 40 / 50 / 60 degrees Celsius.

Heating is useful if high volumes of non volatile solutions, e.g. aqueous samples are to be applied AND the substances involved are not sensitive to heat.

Number of tracks

indicates the number of applications on an HPTLC/TLC plate, according the sequence table.


electronic procedure to shift the detector zero point.

Operation Qualification

or OQ is a procedure performed at the site of and following installation with the purpose of being able to use the instrument under the regulations of GLP/GMP. The OQ is repeated at certain intervals recommended by the manufacturer or defined by the customer’s QC department. It documents that all modules of the equipment perform consistently throughout the specified operating ranges.

The person responsible for the IQ usually performs the initial OQ. In order to qualify for a CAMAG OQ Certificate, this procedure is to be performed by a Product Specialist, certified by CAMAG.

Optical filter

device to affect the bandwidth and thus the intensity of transmitted light. See also Cut-off filter and Grey filter.

Optimize optical system

selects between the monochromator bandwidth 20 and 5 nm. Normal scanning is done at 20 nm with more light, while spectra scanning with 5 nm will assure a better optical resolution.


result, which is considered to be outside the statistically possible error range. Statistics theory does not reference outliers because the normal Gauss distribution is defined for all values although the probability is very low for a value outside of 3 sigma.


laboratory equipment for heating/drying glass ware, HPTLC/TLC plates and other items at elevated temperature.


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


O3, is formed from oxygen during operation of the D2 and Hg lamps of the HPTLC Scanner 3. The concentration has been measured to be below 1ppm in a room of approximately 32m3 after running the Scanner during 8 hours using either lamp.


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 noise level). Peaks are detected during integration.

Peak area

sum of all data values between peak start and end.

Peak data

processed numerical information produced during integration of raw data and made available for further processing. Peak data include position, peak area, peak height, area%, height%, etc.

Peak height

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

Peak marker

is a sign on the analog curve showing the start and end of a peak. During manual integration in visionCATS peak markers can be inserted, deleted or moved.

Peak purity

see Purity.

Peak window

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

Performance Qualification

or PQ is a procedure performed with the complete system in order to ascertain proper operating performance under the regulations of GLP/GMP. The PQ has to be performed with the samples, standards and procedures used during normal operating conditions.

The PQ documents that procedure performs consistently in conjunction with the operating environment and all related processes.

Photo multiplier (PM)

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


new name for modern instrumental HPTLC.


a general expression for the stationary phase in HPTLC/TLC. A plate can be an ordinary glass backed HPTLC plate, an HPTLC plate, aluminum or plastic backed HPTLC sheets or any other kind of stationary phase.

Plate Heater

an instrument deigned to uniformly heat the plate, mostly used for derivatization.

Plate size

dimension of an HPTLC/TLC plate, e.g. 20 x 10 cm. The first measure is for the horizontal edge next to which the samples are applied (X-direction on the plate).


Mathematics: An algebraic expression consisting of one or more summed terms, each term consisting of a constant multiplier and one or more variables raised to integral powers.

Polynomial regression

the 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.


after development / chromatography.


before development / chromatography.


exposure of the stationary phase to a defined gas phase (humidity, solvent composition, etc.) prior to development. Pre-conditioning is utilized to affect the chromatographic result.


washing or cleaning procedure of the stationary phase before applying the sample to the HPTLC/TLC plate.

Pre-washing is especially recommended for analysis in low concentrations.

Print preview

a software tool to present on-screen how a protocol or print-out will look. WYSIWYG = what you see is what you get.


is used as output device to print a report (hardcopy).


value, that determines the quality of being a pure chemical substance.

Purity scanning

a spectrum scan mode to determine peak purity. Spectra are scanned in both peak flanks and at peak max.


most modern CAMAG instruments can be qualified. For more information see the respective instrument description.

See also: Design Qualification, Installation Qualification, Operation Qualification, Performance Qualification.


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


or fluorescence quenching is the reduction of UV light cause by substances absorbing UV at or about the wavelength necessary for exiting the fluorescence indicator.


a technique used in the HPTLC Scanner 3 to determine automatically the optimum gain and sensitivity setting for the detector for fluorescence measurement.

r (M,E)

this represents the spectral correlation used for a peak purity check calculated between the spectrum measured at the end of a peak (E) and a spectrum measured at peak max. (M).

r (S,A)

this represents the spectral correlation used for a peak identity check calculated between spectra – both inside the same peak window - measured at peak max. on a standard track (S) and an analysis track (A).

r (S,M)

this represents the spectral correlation used for a peak purity check calculated between the spectrum measured at the start of a peak (S) and a spectrum measured at peak max. (M).


a device holding the sample vials. The ATS4 standard rack can hold 66 sample vials (and the micro titer plate holds 96 wells or positions).

Rack column/row

the position of a sample vial in column A, B, C ….F and row 1, 2, 3….

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.


reagents - mostly in liquid form – are used in derivatization to visualize fractions on an HPTLC/TLC plate. These liquids can be applied to the layer by spraying or immersion.

Rectangular application

an application mode, by which the sample is applied to the HPTLC/TLC plate in rectangular pattern(s). Application of rectangular patterns is possible only by the spray-on technique.

Reference amount

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

Reference PM

the second PM in the HPTLC Scanner 3 used for monitoring and adjusting for changes in light intensity.

Reference spectrum

the lamp and plate material spectrum measured before real spectrum measurement starts. This spectrum is used for scaling the measured spectrum properly.


a scanning mode of the HPTLC scanner. Light diffusely reflected by the plate is measured in this mode. See also Transmission.


ratio of the amount of light being diffusely reflected by the plate and the amount of light being supplied to the object.


a mathematical procedure to fit a function to a data vector (set of x/y values) based on minimization of squared differences, also called least squares fit.

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 or polynomial regression to calculate the results.

Rel. Response factor

the response of the internal standard related to the response of the unknown. This calculation is used during internal standard calculation (classical mode) only. In order to use it correctly the response (AU/unit weight) of all substances involved has to be known.

Normally the difference in response between the substances is ignored and the factor 1.00 is used.

Spectra used to calculate the correlation.

  • For ‘purity’ the spectra measured at the peak slopes are “related spectra”

  • For ‘identity’ the spectra of the same substance measured on the next left and right standard tracks are used as “related spectra”

Report defaults

customer settings for including/excluding parts of the report.

a heading logo on the report which can represent your company & laboratory.

Report template

saved report settings that can be reused in different analysis

  1. Physics & Chemistry. The act or process of separating or reducing something into its constituent parts.

  2. The fineness of detail attained by a printer or a monitor in producing an image. For printers that form characters from small, closely spaced dots, resolution is measured in dots per inch, or dpi. For a video display the resolution is taken as the total number of pixels displayed horizontally and vertically.

Retention Factor

the relative distance the substance has travelled compared to the distance the solvent front has travelled. Rf = (peak position – application position) / (solvent front position – application position).

RF Tool

a tool to show the RF value of fractions on the digital image.


cleaning of the application syringe, needle or capillary.

Rinsing bottle

a bottle containing the rinsing liquid.

Rinsing solvent

solvent used for syringe or capillary cleaning.

Rinsing time

the time the rinsing solvent flows through the object, i.e. capillary of syringe (in seconds).

S/N ratio

signal to noise ratio.


also named unknown: a mixture of analytes, which needs to be analyzed

Sample ID

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

Sample solvent type

the closest default for the solvent in which the samples are diluted. The applicator needs this information to adapt the dosage speed and other parameters for viscosity and volatility.


an input field in visionCATS for entering data or information about the unknown sample(s)


the mathematical formulas for curve smoothing or filtering defined by these two persons.


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

Scan compartment

the dark room inside the HPTLC Scanner 3 used to measure the HPTLC/TLC plate or other object.

Scan display scaling

describes how the data is displayed on the computer screen.

Scan end pos. Y

the position of the last measurement on all tracks in direction of chromatography, measured in mm from the lower plate edge.

Scan mode

the way how an HPTLC/TLC plate is scanned, e.g. single wavelength scan, dual-wavelength and multi-wavelength scan.

Scan settings

a selection of parameters used to measure the HPTLC/TLC plate.

Scan start pos. X

the start position of the first scan, measured in mm from the left plate edge to the center of the first track.

Scan start pos. Y

the start position of the (all) scan(s) in direction of chromatography, measured in mm from the lower plate edge (usually before the application position).


a device or instrument used to scan / measure the HPTLC/TLC plate or other object. A monochromatic light beam in form of an illuminated slit is used to illuminate the fractions on the plate. The difference between the diffusely reflected light of the plate background and the absorption or fluorescent behavior of the fractions is measured.

Scanning speed

the speed of moving the HPTLC/TLC plate or object underneath the light beam.


search for specific substances without desire for quantification.

Second order filter

optical filters used to suppress secondary order harmonic wavelengths during scan.


the ability to discriminate between two levels of the same property.


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


describes the relation between tracks and samples/standards applied. The sequence is defined at sample application and used during for evaluation.


the light beam, used to illuminate the measuring position on the HPTLC/TLC plate with monochromatic light during measurement.

Slit dimension

length and width of the light beam.

Slit length

the length of the light beam.

  • For spotwise-applied samples the slit length should be larger than the width of the largest fraction.

  • For bandwise applied samples the slit length should be 80% of the band length.

Slit width

the width of the light beam. For HPTLC/TLC applications a slit width of 0.3 ~ 0.4 mm is commonly used since it gives the best S/N ration. Smaller slit widths (0.05 ~ 0.1 mm) are used to scan electrophoresis objects.


the up- or down-’hill’ part of a peak. The steepness of the peak slope is used during peak detection.


serial number. The SN of your visionCATS license is the Product ID in the about dialog, the SN of your instrument is on the rating plate.


is a liquid used for several tasks:

  1. dilution of the sample

  2. as mobile phase during development

  3. cleaning/rinsing.

See also Mobile phase.

Solvent bottle

a bottle containing the solvents to be used for the separation. The AMD uses several solvent bottles, each of them containing another solvent or solvent mixture.

Solvent front

the position of the solvent at the end of a development is measured in mm from the lower plate edge.


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


the application mode used by contact applicators.

Spot application

an application mode, by which the sample is applied to the HPTLC/TLC plate in from of spots. Contact transfer technique is used to apply spots - i.e. the needle or capillary of the application device will touch the HPTLC/TLC layer surface.

Spot check

the procedure of assigning peaks to substance windows.

Spray area

an application mode used by the ATS4 to apply the samples in a rectangular form.

Spray band

an application mode used by the Linomat 5 and ATS4 to apply the samples in the form of a narrow band.

Spray gas

a gas - mostly inert gas, e.g. N2 - used for the spray-on technique during sample application.

Spray-on needle

special tapered needle used for the spray-on technique in Linomat and ATS4.

System suitability test

test to monitor the suitability of the running analysis for the designed task. The visionCATS option System Suitability Test offers a set of tools for this task.


substance of known amount running on a standard track. For quantitative HPTLC (calibration) a different number of standard tracks and levels are necessary.

Stationary phase

the plate material on the HPTLC/TLC plate, usually Silica Gel.


used in the application sequence table to indicate if the parameters are correct. If the parameters are correct, the software will show “OK” if they are not correct “Not OK”.

Note: the sample application will only start, if the Status is OK.

Std Level

a known substance amount (in mg, μg or ng) required for quantitative evaluation. For a single-level only one known amount is required, while with multi-level calibration 3~10 different amounts (levels) are needed.

Stock solution

the solution in which the samples or standards have been dissolved.


impurity, degradation- or by-product. The routine for calibrating sub-components by means of the diluted main component is described in USP as “related compounds”.


represent a chemical substance (a form of matter that has constant chemical composition and characteristic properties).

Substance assignment

a routine in visionCATS used to link a fraction on the plate to a substance in the substances 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 system.

Substance table

input fields for the substance(s) i.e. purity, manufacturer, expire date, etc. in Definition.


used in applicators to apply defined volumes of sample onto the HPTLC/TLC layer. Depending on the application volume, different sizes of syringes are available.

Syringe needle

is fixed in or mounted to the syringe and used to pick-up the sample. During application the sample is applied from the needle tip onto the layer by either contact transfer or by the spray-on technique.

With ATS4 different needles are available for those tasks.


an entry for temperature is used for drying an HPTLC/TLC plate after pre-washing, chromatography or during derivatization.


see Method or Report template


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

Threshold area

peaks with an area lower than this limit will be discarded.

Threshold height

peaks with a height lower than this limit will be discarded.

Threshold slope

peaks with a (start) slope less steep than met by this limit will be discarded.


Thin Layer Chromatography, see also HPTLC.


range on the HPTLC/TLC plate representing one chromatogram. A track can be either of type sample (unknown) or standard.

Track optimization

procedure to scan tracks several times with small positioning differences and then optimize the data. Available as an option with visionCATS.


the amount of light passing through an object.

Transmission mode

a scanning mode of the HPTLC Scanner 3 for measuring transparent objects.


the left pane of the document view showing an explorer like tree of the active HPTLC steps.

Twin Through Chamber

a device for development of HPTLC/TLC plates.

Ultraviolet Radiation

UV is the region of the electromagnetic wavelength (light) spectrum between of 400 and 10nm.

Ultraviolet radiation is often divided into three categories based on wavelength, UV-A (400 – 315nm), UV-B (315-280nm), and UV-C (280-10nm).


a unit of electrical tension (Volt).


is a procedure, ensuring that a procedure is suitable to perform a certain analytical task. Qualified staff using qualified equipment can use a validated method (see also Qualification).


a glass container holding a small amount of the dissolved sample or standard, usually placed in a vial rack.

Vial rack

a device holding one or more vials.

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 range of the light covering wavelengths between approx. 400 – 750nm


“visionCATS – next generation HPTLC software for qualitative analysis” is the next generation software for qualitative 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. visionCATS software supports chromatographers who use HPTLC for quality control, identification, and detection of adulteration, as well as stability studies in various fields of application. For the moment the software is geared to qualitative work including all aspects of qualitative HPTLC be it for cGMP compliant routine work or flexible scientific research.


a measure for the amount of liquids


a message to indicate an abnormal condition.


material/liquid that is being disposed of.

Waste bottle

a bottle to collect the waste liquids.


in densitometry the wavelength is measured in nm (nanometer).

White balance

an electronic adjustment used by digital- or video-cameras to best display a white area. This “white balance” depends on what type of illumination is used.

  • <Auto> will try to find a optimum white balance, but is best suited for outdoor photography.

  • <Daylight> is used with outdoor daylight illumination,

  • <Fluorescent> is to be used with all kind of artificial light (fluorescent tubes).

Window size [mm]

a range in millimeters in which peaks are identified (assigned) as belonging to the same component (substance).


the X direction on the HPTLC/TLC plate is the direction perpendicular to the direction of chromatography. X positions represent the positions of different tracks on the plate.


the Y direction on the HPTLC/TLC plate is the direction of chromatography. Y positions represent positions within a track of 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 value 0. The scaling of the data values to the analog cure’s offset or zero line is done at display time.

ZERO adjust

zero adjust is the procedure of automatically adjusting the PM current to a preset value.


in HPTLC/TLC also used for substances or fractions on the chromatographed plate.


procedure to enlarge (magnify) or reduce a window.

Zooming In

enlarges the size of the image.

Zooming Out

reduces the size of the image.

µg (microgram)

10 -6 gram

µL (microliter)

10 -6 liter

µm (micrometer)

10 -6 meter

µV (microvolt)

10 -6 Volt


The α-front is the actual visible front during development of the HPTLC/TLC plate.

Possible de-mixing of the eluent can cause secondary horizontal front lines (β-, γ-fronts, etc.).


during development of the HPTLC/TLC plate de-mixing of the eluent will cause horizontal front lines. The first secondary front below the actual solvent front is called the β-front.


half Peak window, from Peak max to top or bottom of the window.