J. Planar Chromatogr. 26, 172-179 (2013). OPLC with on-line detection and fractionation, in-situ sample clean-up in the planar layer adsorbent bed, direct bioautography (DB), OPLC–MS, solid phase microextraction (SPME)–GC–MS, and LC–MS/MS for the bioassay-guided isolation and characterization of bioactive compounds from chamomile flower extract. The bioassay-guided isolation of antibacterial chamomile components was based on OPLC separation with on-line detection and fractionation combined with previous sample clean-up in-situ in the adsorbent bed after sample application. First the adsorbent layer was partially pre-weted between the edge of the layer and the sample application zone with the goal to fill up the “dead” area behind the trough, which leads the components to leave the adsorbent layer during the clean-up step. With this process, the zone behind the trough can be protected from stucking of any components in it, otherwise the stucked compounds could be detected continuously during the separation/detection/fraction collection. During the in-situ sample clean-up the mobile phase flow was in the opposite direction, from outlet toward inlet of the chamber. In this step the load of the adsorbent can be decreased for the fractionation, which is done in the normal direction of the mobile phase.

J. Planar Chromatogr. 26, 180-189 (2013). HPTLC of 2,4-dinitrophenyl-5-L-valine amide derivatives of some amino acids (leucine, isoleucine, valine, asparagine, cysteine, tryptophane) L and D-enantiomers on RP-18 with aqueous buffer pH 2.2 (1.47 mM citric acid, 0.06 mM disodium hydrogen phosphate) and acetonitrile 50 %. The statistic evaluation of the migration distance compared with pressurized planar electrochromatography (PPEC) shows similar RSD.

CBS 110, 5-7 (2013). HPTLC of extracts of (1) Nauclea diderrichii, (2) Sarcocephalus pobeguinii, (3) Hua gabonii, (4) Morinda lucida, and (5) Momordica foetida on silica gel with A) toluene - ethyl acetate 19:1; B) chloroform - methnaol - water 35:15:2; C) ethyl acetate - acetic acid - formic acid - water 100:11:11:27, D) acetonitrilie - water - formic acid 15:4:1, and E) 1-butanol - acetic acid - water 7:1:2. For (1) mobile phases B and C were best suited, for (2) mobile phase B, for lipophilic compounds of the essential oil of (3) mobile phase A and for (4) and (5) mobile phase B. Bioautographic analysis using alpha- and beta-glucosidase enzym assays, acetylcholinesterase inhibition assay, and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical reagent for detecting radical scavenging activity.

Chinese J. of Med. Guide 2 (9), 109-110 (2012). Coptis chinensis is a herbal TCM drug for relieving internal heat or fever. High speed countercurrent chromatography (HSCCC) is frequently applied to analyse the alkaloids of Coptis chinensis. To optimize the solvent system of HSCCC the method for determination of the partition coefficient of Coptis chinensis alkaloids was done by TLC and fluorescence spectrophotometry. The major alkaloids are coptisine, berberine, palmatine and epiberberine. The crude drug was extracted with ethanol and contained 9.2 % coptisine, 18.5 % berberine, 4.0 % palmatine and 3.5 % epiberberine. TLC on silica gel with cyclohexane – ethyl acetate – isopropanol – methanol – water – triethylamine 6:7:2:3:1 with chamber saturation for 20 min with ammonia vapors, detection at UV 366 nm. The zones were quantitatively scraped off the layer and eluted with ethanol for fluorescence spectrophotometry at UV 366 nm. Quantification by external standard calibration over the linearity range of 0.5-2.5 g/L for coptisine, berberine and epiberberine with standard addition recovery of 98.3 % (%RSD = 1.9 %, n=6), 95.3 % (%RSD = 3.4 %, n=6), 103.9 % (%RSD = 2.6 %, n=6), respectively; and 1.0-3.0 g/L for palmatine with standard addition recovery of 97.6 % (%RSD = 3.7 %, n=6). Calculation of the partition coefficient, i.e. the ratio of observed values of the analytes from the two phases, respectively, with the results for coptisine 2.20, berberine 0.29, palmatine 0.21 and epiberberine 0.61.

CBS 107, 11-12 (2011) HPTLC of tiliroside (a cosmetic active obtained by extraction from a plant of the family Sterculiaceae) and side components kaempferol-3-glucoside, kaempferol-3-rutinoside, kaempferol, and coumaric acid on silica gel with ethyl acetate - formic acid - acetic acid- water 100:11:11:27 + 1% heptane. Detection under UV 366 nm after spraying with natural products reagent (1 % diphenylborinic acid 2-aminoethylester in methanol) and under white light after spraying with anisaldehyde sulfuric acid reagent (0.5 mL anisaldehyde in 85 mL methanol with 10 mL acetic acid and 8 mL conc. sulfuric acid) and heating at 90-125 °C for 15 min. Quantitative absorption measurement of tiliroside at 315 nm using a 4-point calibration via peak area. The tiliroside contents in the sample extracts were determined as: 1 = 1.09 µg (RSD = 0.4 %), 2 = 0.93 µg (RSD = 0.8 %), 3 = 1.19 µg (RSD = 1.2 %) and 4 = 3.32 µg (RSD = 0.3 %). During the side component analysis no kaempferol, coumaric acid, and glucose were detected in the tiliroside samples. Small amounts of kaempferol-3-glucoside and kaempferol-3-rutinoside were found. HPTLC covers several tasks: quantification of the active ingredient in a complex plant matrix for determining the quality of the raw material, in-process control for monitoring the impurity profile during the manufacturing process and the quantification of the active ingredient in the final product.

J. Planar Chromatogr. 26, 299-305 (2013). The review described the main reasons that transformed standard TLC into a reliable and regulatory acceptable technique. Different aspects that allowed the incorporation of quantitative TLC to the QA systems such as automation, standardization of analytical procedures and operational qualification and performance qualification, as well as development of digital technology and new instruments are discussed.

ex O.Berg) for its major anthocyanins by densitometry. J. Planar Chromatogr. 26, 363-369 (2013). HPTLC of delphinidin-3,5-diglucoside (1), petunidin-3,5-diglucoside (2), and malvidin-3,5-diglucoside (3) in the fruits of Eugenia jambolana on silica gel with ethyl acetate - formic acid - acetic acid - water - methanol 126:19:10:32:12. Quantification by absorbance measurement at 529 nm. The hRf values for (1), (2) and (3) were 17, 24 and 34, respectively. Linearity was in the range of 400-1000 ng/zone for (1) and (2) and 200-500 ng/zone for (3). LOD and LOQ were 84 and 283 ng/zone for (1), 72 and 242 ng/zone for (2) and 43 and 154 ng/zone for (3), respectively. Average recoveries were 95.4 % for (1), 96.3 % for (2) and 97.3 % for (3). Intermediate/interday/intra-day precision was below 5 % (n=3).

J. Liq. Chromatogr. Relat. Technol. 37, 528-537 (2014). HPTLC of prednisolone acetate (1) and moxifloxacin hydrochloride (2) in pharmaceuticals on RP-18 with methanol - water 7:3 + 1 drop triethylamine. Quantitative determination by absorbance measurement at 274 nm. The hRf values for (1) and (2) were 50 and 72, respectively. Linearity was in the range of 600-3600 ng/zone for (1) and 300-1800 ng/zone for (2). LOD and LOQ were 57 and 173 ng/zone for (1) and 27 and 83 ng/zone for (2). Recoveries (by standard addition) were in the range of 100-102 % for (1) and (2). Intermediate intra- and inter-day precision was below 2 % (n=3).