Micro Planar Liquid Chromatography has been developed in 2007 at Institute for Chromatography.
It was published in special parts at certain international symposia in 2008 and 2009 -
one paper as ppt/pdf file is available through this link:
A series of three further ppt/pdf based papers are now available by a click on HERE .
Select after loading the chapter PAPER. The ppt/pdf files tell about the stepwise development of µ-PLC.
NOTE: you should have ADOBE Reader 9.0 or higher on your computer to faster load and see the papers as ppt/pdf file. MS IE7 and higher, Firefox 3.5.3 or higher, Safari 4.04 or higher are browsers which load the material together with the pdf-reader program from ADOBE.

µ-PLC offers a completely unexpected way to get 100% safe analytical data by a “one shot” compare analysis of two samples: an authentic one A and a questionable one Q. For a quick information click here.

The first Internet book of the author which mainly contains µ-PLC information but also former instructions about TLC and linear HPTLC is published.
Just click on the underlined word “published”

We are still working on the detailed concept of the new micro technique µ-PLC, its fundamental difference to TLC, and HPTLC, its qualitative and quantitative application and its up-to-now not believed quantitative precision and accuracy (often a factor ten better than with top instrumental HPTLC of today). µ-PLC is the only planar chromatography technique with a sampling volume range from nl to one full ml. It is up to now the only technique which allows for 100% save critical sample comparison. This is possible as the samples overlap locally each other but by part only in bow areas within a limited plate range, where physics, chemistry and time is absolutely identical for the chromatography of to be compared neighboring samples. This situation never exists with any other technique in chromatography. Thus if in µ-PLC samples differ than they differ by 100 % guarantee. In all other chromatography techniques a difference may be caused by time or any of the very many physical and chemical differences of and inside columns, capillaries or plates. Thus there is always a certain range of systematic errors possible causing false differences ending up this way with open questions in analytical results. Of course: absolute correct taking treating and giving samples is a condition sine qua non - a real analyst is able to do it.


One pair of to be compared samples - an authentic one (named A) with a questionable one (named Q) - is sampled and focused in such a way, that about 10 to 20 % of the sample bows overlap. Note: per plate three of such compare pairs could be sampled or two differing samples Q touching one sample A - but see the figure below. The chromatographic separation is selected in such a way, that important parts of the compare samples reach a relative position
Pr of above 0.2 and below 0.8. NOTE: Pr is used instead of the classical Rf. Pr means relative position. The radius of the circular chromatogram has the value Pr = 1.0

In the “overlap area” of the chromatograms there exists a special analytical condition not available by any other analytical procedure (at least not known to the author prior to 2009), where all physical and chemical conditions are strictly equal to the overlapped substances. As the separation is strictly simultaneous, there is also no any time effect active, which otherwise could easily produce systematically falsifying effects to the compare samples. If the chromatograms for the questionable sample differs qualitatively and / or quantitatively from the authentic sample, sample Q is NOT equal to the sample A. Product Q differs from product A.
This result has the highest possible safety: it is 100 % sure. No repetition, no statistics necessary in case the samples have been taken, prepared and given totally error free. This however is the professional condition sine qua non for a trained analyst, as everything he/she has to know about correct sampling is standard knowledge since more than hundred years,


In sector 1, 3, 5, and 6 are samples A or Q. Sectors 2, 4 and 7 are
µ-PLC “overlap areas” in which the physics and chemistry for the neighboring samples is strictly equal. As there is also no time difference for the chromatography of the neighboring substances there is no way to see any falsifying systematic effect changing the chromatography conditions so that we realize: NO systematically falsifying influences, which could be responsible for not really existing “differences”.
Compare sector 3 with 4 and 5 : The sample composition in 3 has nothing to do with the composition in 5. It may be, the main substance in 5 - the more dark one - may (or may not) be equal to the weaker one at a lower Pr value in 3. But this is of no importance. The analytical question was: is 3 equal 5 ? NO, definitively not, for sure. If the pharma product showing some substances in 5 has been reproduced by a sister company and they got the product from which only the detectable substances are visible in 3, for 100 % sureness the sister company failed. 5 is not 3. There is NO full (complete) analysis necessary. Production errors, quality control and hundred other market, competitor or falsifier questions can be checked this way quick, extremely economical, 100 % safe.

NOTE: what about with HPLC or GC ? Forget 100% safety in a one shot analysis. Just the time difference between a
Q-analysis to be compared with an A- analysis could produce differences by all the effects which are correlated with time in Chromatography. What about with TLC, HPTLC ? There are no compare areas. The run tracks are locally isolated from each other. We know of gradients along X as well as Y axes in standard TLC / HPTLC, OPLC...

Latest  Micro-HPTLC news Aug. 2013:
We found, that “multi focussing” can drastically enlarge the separation power so that substance circles at position Rf(circular) = 0.50 can be base line separated from substance circles at position Rf(circular) = 0.52. This results in a separation number of 48 to 50, which is standard of good classically packed HPLC columns. The following figure shows a compare analysis of an authentic Viagra pill versus a product called KAMAGRA. No comments with respect of clearly visual by products in a concentration level of 50% relative to the content of Sildenafil. The substance circlre which is exactly going round through the overlapped sample area as well as to the only attached circle part is the Viagra effective substance Sildenafil. See the figure here below. About the procedure of ‘multi focussing’ we will report in

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[Home] [We can help] [Systematic C-Errors] [Statistics] [Error Detector "sf4"] [Sampling/Calibration] [Qual.Error GC] [Quant.Error GC] [Qual.Error HPLC] [Quant.Error HPLC] [Qual.Error PLC] [Quant.Error PLC] [Integration] [Chrom. Combination] [µPLC Micro Planar LC] [Altern.Chrom.Theory] [Contact IfC] [About the Author]