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Author: Subject: Digitally Enhanced Thin-Layer Chromatography (DE-TLC)
Mush
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[*] posted on 4-12-2016 at 14:40
Digitally Enhanced Thin-Layer Chromatography (DE-TLC)


Cheap and relatively easy tool for quantitative determination by TLC. :D

Digitally Enhanced Thin-Layer Chromatography: An Inexpensive, New Technique for Qualitative and Quantitative Analysis

Amber Victoria Irish Hess

Massachusetts Institute of Technology, Cambridge, MA 02139-4310
J. Chem. Educ., 2007, 84 (5), p 842
DOI: 10.1021/ed084p842
Publication Date (Web): May 1, 2007


The objective: Thin-layer chromatography (TLC) is a widely used method for qualitative analysis to determine the number of components in a mixture, to determine the identity of two substances, or to monitor the progress of a reaction.

The more accurate high-performance TLC (HPTLC) is better suited for quantitative analysis. Unfortunately, HPTLC requires expensive equipment which most high schools and colleges cannot afford.

I demonstrate that if digital photography is combined with regular TLC, it can perform highly improved qualitative analysis as well as make accurate quantitative analysis possible.

Methods/Materials
This novel, "digitally-enhanced" TLC (DE TLC) is very easy to use. A fluorescent TLC plate is illuminated with UV light and a picture of the plate is taken with a digital camera. Then, on a computer, using either TLC Analyzer, the public domain software I wrote, or common photo-editing software, one can quickly produce multi-spectral scans, densitograms, and calibration curves--output previously available only from more expensive equipment or complex procedures

Results
With high linearity (R^2 ~ 0.97 - 0.99), good repeatability RSD < 5%), and detection limits approaching those of HPTLC, DE TLC produces surprisingly good results for such inexpensive equipment..

Conclusions/Discussion
Digitally-Enhanced TLC is a valuable tool that can be added to every chemist's TLC toolbox. Since this technique is much less expensive than other quantitative chromatographic methods, DE TLC is ideal for high school and college labs.

This project developed an inexpensive technique using digital photography that is an alternative to a $30,000 piece of equipment for chemical analysis.

This is her blog:

http://www.sciencebuddies.org/science-research-papers/tlc_an...

Anyone can contact her by email for further questions regarding to this method.

J Labelled Comp Radiopharm. 2013 Sep;56(11):544-52. doi: 10.1002/jlcr.3052. Epub 2013 Jul 23.

Digitally enhanced thin layer chromatography: further development and some applications in isotopic chemistry.

Improvements to thin layer chromatography (TLC) analysis can be made easily and cheaply by the application of digital colour photography and image analysis. The combined technique, digitally enhanced TLC (DE-TLC), is applicable to the accurate quantification of analytes in mixtures, to reaction monitoring and to other typical uses of TLC. Examples are given of the application of digitally enhanced TLC to: the deuteromethylations of theophylline to [methyl-(2)H3]caffeine and of umbelliferone to [(2)H3]7-methoxycoumarin; the selection of tertiary amine bases in deuterodechlorination reactions; stoichiometry optimisation in the borodeuteride reduction of quinizarin (1,4-dihydroxyanthraquinone) and to the assessment of xanthophyll yields in Lepidium sativum seedlings grown in deuterated media.

DE-TLC; Lepidium sativum carotenoids; [2H3]7-methoxycoumarin; [9,10−2H2]1,4-anthraquinone; deuteromethylation; digitally enhanced TLC; methyl−2H3]caffeine; quinizarin; umbelliferone


Less advanced technic but based on the same principle.

Quantitative and Qualitative TLC Analysis of 5meo DMT
By Clear Light and Desert Sun
https://erowid.org/archive/rhodium/pdf/5-meo-dmt.quant-qual....

Attachment: 10.1002@jlcr.3052_Digitally enhanced thin layer chromatography.pdf (775kB)
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[Edited on 4-12-2016 by Mush]
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[*] posted on 11-9-2019 at 15:06


12-2018

Studies in hydrogel microfluidics and developmentof low cost imaging for quantitative TLC in the undergraduate teaching laboratory

Alexandra Marie
Anderson University of Tennessee

....For this undergraduate lab, we chose the approach of digitally-enhanced TLC (DE-TLC), which combines a digital camera with regular TLC equipment to enable quantitative analysis (10). DE-TLC was introduced in 2007 with an accompanying public domain analysis software, but the softwareis now obsolete and inoperable on many modern computer systems. In this work, the DE-TLC method was revisited using free public domain software(i.e.NIH ImageJ) for quantitative TLC analysis using indirect fluorescence detection. To interest students, counterfeiting of the anti-malarial drug chloroquine was chosen as the proposed application.

https://trace.tennessee.edu/cgi/viewcontent.cgi?article=6772...


An Image Analysis System for Thin-Layer Chromatography Quantification and Its Validation

Tang Tie-xin and Wu Hong*

Abstract

Quantitation of thin-layer chromatography (TLC) using image analysis is attractive for its low cost and convenience. The image analysis is investigated by designing a digital imaging system with simple equipment, developing an image analysis software based on our algorithm, and validated the system in the TLC quantitative assay of cichoric acid present in Echinacea purpurea (L.) Moench. TLC used a polyamide thin-layer plate with chloroform-methanol formic acid-water (3:6:1:1) as the mobile phase and 3% (m/v) aqueous aluminum chloride solution as the visualization reagent. Images are acquired with a standard digital camera under a UV viewing lamp (365 nm) in a dark room. The three-dimensional grayscale digital image dataset (x, y, gray) is reduced to twodimensional dataset (distance, accumulative gray) and then plotted as a curve. The area under the peak corresponding to the cichoric acid spot is integrated and used for quantitation. The whole method was validated by the assay tests of detection limit, calibration curve, repeatability, reproducibility, and recovery. The results showed that our digital imaging method and image analysis algorithm were applicable for the quantification of TLC. The whole method is convenient, efficient, and moderately accurate for the quantitative assay of cichoric acid present in Echinacea purpurea (L.) Moench.

Attachment: tie-xin2008.pdf (341kB)
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Software for Image Analysis
Profiles of five programs for quantifying data from Westerns, dot blots, gels, and colony cultures

https://www.the-scientist.com/lab-tools/software-for-image-a...

[Edited on 12-9-2019 by Mush]
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[*] posted on 2-8-2021 at 15:13


A Toolkit to Quantify Target Compounds in Thin-Layer-Chromatography Experiments

Niamh Mac Fhionnlaoich, Stuart Ibsen, Luis A. Serrano, Alaric Taylor, Runzhang Qi, and Stefan Guldin*

J. Chem. Educ. 2018, 95, 12, 2191–2196
Code:
https://pubs.acs.org/doi/10.1021/acs.jchemed.8b00144

Abstract
Thin-layer chromatography (TLC) is one of the basic analytical procedures in chemistry and allows the demonstration of various chemical principles in an educational setting. An often-overlooked aspect of TLC is the capability to quantify isolated target compounds in an unknown sample. Here, we present a suitable route to implement quantitative analysis in a lesson plan. We provide both a stand-alone software and an online webapp that allow students to obtain quantitative information from a developed TLC plate and present two suitable experiments, namely, the absorbance-based quantification of the colorant Sudan IV and the fluorescence-based quantification of rhodamine 6G, a fluorophore widely used in biotechnology. Students conduct TLC experiments following established protocols, take pictures of their TLC plates with mobile phones, and subsequently quantify the different compounds in the separate bands they observe.

The Supporting Information is available on the ACS Publications website at DOI: 10.1021/acs.jchemed.8b00144.

Supporting Information with qTLC software and webapp tutorials; details on MinPeakProm, Divisor, the signal-integration process, and background subtraction; image-acquisition guidelines; choice of concentration range; and overview of experimental errors (PDF)
Student handout with instructions on experimental TLC (PDF)
Student handout with instructions on image analysis and data acquisition with the qTLC software (PDF)
Student handout with instructions on image analysis and data acquisition with the qTLC webapp (PDF)
All MATLAB components for customization and further development of the qTLC software (ZIP)
Links for installation of the qTLC software on MacOS with separate MATLAB Runtime installation, standalone installation of the qTLC software on MacOS, installation of the qTLC software on Windows with separate MATLAB Runtime installation, and standalone installation of the qTLC software on Windows (PDF)

Video

Code:
https://www.youtube.com/watch?v=rSNVhVJRvws



qTLC A webapp to quantify chemical compounds via thin layer chromatography.
Code:
https://qtlc.app/


Attachment: acs.jchemed.8b00144.pdf (3.4MB)
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Application of smartphone in detection of thin-layer chromatography: Case of salvia miltiorrhiza

Journal of Chromatography A 1637 (2021) 461826

Abstract
In this work, a smartphone-based device was constructed for thin-layer chromatography (TLC) detection and semi-quantitative analysis of the components of Salvia miltiorrhiza . The key construction and shoot- ing parameters were investigated by the relative peak area and signal-to-noise ratio. The best conditions were as follows: shooting height, 17 cm; angle between the UV lamp and TLC plate, 58 °; exposure com- pensation, 0~0.2 EV; and shutter speed under daylight and UV 365 nm, 1/50 s and 1/5 s, respectively. These ideal conditions could be replicated by smartphones from different brands with different versions of software. With good precision, repeatability and stability, the developed device was used for the semi- quantitative analysis of salvianolic acid B, rosmarinic acid, cryptotanshinone, tanshinone I, tanshinone IIA, and miltirone in the TLC analysis of 10 batches of S. miltiorrhiza . The results were compared with those obtained by a TLC densitometric scanner and two common types of image processing software, i.e., Gel- analyzer and ImageJ . Except for salvianolic acid B in the TLC densitometric scanner, all results were not significantly different among these methods, which suggested that smartphones might be a useful tool for the quality control of traditional Chinese medicines.

Attachment: j.chroma.2020.461826.pdf (1.6MB)
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Attachment: j.chroma.2020.461826.sup.docx (1.9MB)
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[Edited on 2-8-2021 by Mush]
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