Thin layer chromatography is one of the simplest and cheapest approach of separation, widely used in for the separation purpose. Thin layer chromatography (TLC) is the most widely used technique for separating phytochemical compounds in plant extracts and has been coupled with mass spectrometry to provide sensitive and specific analysis. However, several analytical issues affect these methods, making them non-viable for long term and high-throughput analysis. A simple and cheap design for interfacing thin layer chromatography (TLC) with electrospray ionization mass spectrometry (ESI/MS) was developed to scan and characterize compounds on TLC plate termed as sawtooth thin layer chromatography-electrospray ionization/mass spectrometry (sawtooth TLC-ESI/MS) to directly scan and characterize compounds on developed TLC plates that were modified into sawtooth pieces to facilitate rapid analysis. The developed TLC plate was rapidly and easily modified into two sawtooth-edged pieces that were positioned on an XYZ stage so that one of the triangular tips was pointed toward the MS inlet. A drop of methanol and high DC voltage was applied at the tip to induce ESI. After the analytes in the first tip were analyzed, the TLC piece was moved so that the second triangular tip was pointed toward the MS inlet for analysis. The process was repeated until all the triangular tips on the piece were analyzed. In this manner, the analytes, no matter visible or non-visible bands, were scanned and characterized. A mixture of dye standards and Datura metel flower extract, common adulterant’s in chines herbal medicine, illegal dyes in food stuff was analyzed to demonstrate the capability of sawtooth TLC-ESI/MS on scanning and characterizing chemical compounds on the TLC plates.

Thin layer chromatography is one of the simplest and cheapest approach of separation, widely used in for the separation purpose. Thin layer chromatography (TLC) is the most widely used technique for separating phytochemical compounds in plant extracts and has been coupled with mass spectrometry to provide sensitive and specific analysis. However, several analytical issues affect these methods, making them non-viable for long term and high-throughput analysis. A simple and cheap design for interfacing thin layer chromatography (TLC) with electrospray ionization mass spectrometry (ESI/MS) was developed to scan and characterize compounds on TLC plate termed as sawtooth thin layer chromatography-electrospray ionization/mass spectrometry (sawtooth TLC-ESI/MS) to directly scan and characterize compounds on developed TLC plates that were modified into sawtooth pieces to facilitate rapid analysis. The developed TLC plate was rapidly and easily modified into two sawtooth-edged pieces that were positioned on an XYZ stage so that one of the triangular tips was pointed toward the MS inlet. A drop of methanol and high DC voltage was applied at the tip to induce ESI. After the analytes in the first tip were analyzed, the TLC piece was moved so that the second triangular tip was pointed toward the MS inlet for analysis. The process was repeated until all the triangular tips on the piece were analyzed. In this manner, the analytes, no matter visible or non-visible bands, were scanned and characterized. A mixture of dye standards and Datura metel flower extract, common adulterant’s in chines herbal medicine, illegal dyes in food stuff was analyzed to demonstrate the capability of sawtooth TLC-ESI/MS on scanning and characterizing chemical compounds on the TLC plates.

Paper review..................................................................................i
Acknowledgements......................................................................ii
Chinese Abstract.......................................................................... iii
English Abstract............................................................................iv
Content..........................................................................................v
Figure content...............................................................................vi
Table content ................................................................................xi
List of Abbreviations.....................................................................xii
Chapter 1 Introduction......................................................................... 1
1.1 Thin layer chromatography (Historical sketch) ……………….……... 1
1.2 General description of TLC………………………………….……..... 3
1.3 Retention factor ……………………………….…………………….. 4
1.4 Apparatus ………………………….……………………………….....5
1.5 Thin-Layer Chromatography Derivatization…………………………. 14
1.6 TLC Derivatization Methods………………………………………… 15
1.7 Thin layer Chromatogram Evaluation………….……………………. 16
1.8 TLC Evaluation with Derivatization………………………………….. 17
1.9 Detection and Characterization by TLC-MS …………………………22
1.10 TLC-MS Techniques…………………………………………….......................22
1.11 Ambient TLC–MS using ESI-based ion sources......................... 24
1.12 Study Aims...................................................................... 28
Chapter 2 Materials & Methods......................................................... 38
2.1 Reagents, standards, & samples............................................. 38
Chapter 3 Instrumentation............................................................. 42
3.1 TLC separation Mixture of dyes.............................................42
Thin-Layer Chromatography Derivatization............................... 14
TLC Derivatization Methods................................................ 15
Thin layer Chromatogram Evaluation...................................... 16
TLC Evaluation with Derivatization......................................... 17
Detection and Characterization by TLC-MS ..............................22
TLC-MS Techniques...................................................... .22
3.2 TLC separation D. metelflower...........................................................42
3.3 TLC analysis of A. carmichaelii...........................................................43
3.4 TLC analysis of Panax ginseng............................................................43
3.5 TLC Separation of drugs in Herb.........................................................43
3.6 TLC separation of Viagra and herb.......................................................43
Chapter 4. Results and Discussion..............................................................45
4.1 Sawtooth TLC-ESI-MS system.........................................................45
4.2 Application of sawtooth TLC-ESI/MS system for the study of dyes............. 48
4.3 Application of sawtooth TLC-ESI/MS system Dried Datura metel (D. metel)... 57
4.4 Application of sawtooth TLC-ESI/MS system TLC analysis of A. carmichaelii.................................................................................... 60
4.5 Sawtooth TLC-ESI/MS analysis of the A. carmichaelii extract.....................62
4.6 Application of sawtooth TLC-ESI/MS system TLC analysis of Panax ginseng..........................................................................................66
4.7 Sawtooth TLC-ESI/MS analysis of P. ginseng extract..............................68
4.8 Sawtooth TLC-ESI/MS analysis of Drugs in herbal extract........................72
4.9 Sawtooth TLC-ESI/MS analysis of Viagra in herbal extract........................77
4.10 Sawtooth TLC-ESI/MS analysis of food dyes........................................80
4.11 Sawtooth TLC-ESI/MS analysis of illegal food dyes............................... 85
Chapter 5 Conclusion........................................................................... 88
References ....................................................................................... 90

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