J. Chinese Trad. Patent Med. 30 (12), Supl. 4-6 (2008). TLC of the TCM drug extracts on silica gel with 1) dichloromethane - ethyl acetate - methanol - water 15:40:22:10; 2) petroleum ether (60-90 °C) - diethyl ether 3:2; 3) petroleum ether (60-90 °C) - ethyl acetate 25:2; 4) n-butanol - acetic acid - water 4:1:2; 5) chloroform - diethyl ether 1:1. Detection 1) by spraying with 10 % sulfuric acid in ethanol followed by heating at 105 °C until coloration; 2) under UV 365 nm; 3) under UV 254 nm.

J. Chromatogr. A 1217 (23), 4655-4662 (2010). Development and application of electrospun glassy carbon nanofibers for ultra-thin layer chromatography (UTLC). The carbon nanofiber stationary phase was created through electrospinning and pyrolysis of SU-8 2100 photoresist, which resulted in glassy carbon nanofibers with diameters of 200-350 nm that form a mat structure with a thickness of 15 µm. The chromatographic properties of UTLC devices produced from pyrolyzed SU-8 heated to temperatures of 600, 800, and 1000 °C were investigated. By use of Raman spectroscopy and scanning electron microscopy the physical and molecular structure of the nanofibers at each temperature was determined. The carbon UTLC devices were suitable for the analysis various dye mixtures and also allowed separation of three FITC-labeled essential amino acids (lysine, threonine, phenylalanine). The electrospun glassy carbon UTLC plates showed good retention properties, plate number values above 10000, and physical and chemical robustness for a range of mobile phases.

J. Planar Chromatogr. 23, 201-207 (2010). TLC and HPTLC of 17 5,5-disubstituted hydantoins on silica gel with ethyl acetate - toluene (with 30-60 % ethyl acetate) and acetonitrile - toluene (with 30-50 % acetonitrile) and on RP18 with methanol - water (with 56-80 % methanol) and acetonitrile - water (with 30-60 % acetonitrile) at room temperature without chamber saturation. Detection under UV 254 nm. The effect of the structures of the derivatives on their retention in both normal and reversed-phase modes was investigated by use of QSRR and molecular descriptors. Cross-validation indicated the best models are reliable QSRR models.

J. Chromatogr. A 1217 (43), 6600-6609 (2010). A review on hyphenations of planar chromatography and its most important subcategory HPTLC. Examples from the field of natural product search, food, and lipid analysis point out the hyphenation with effect-directed analysis and mass spectrometry and illustrate the efficiency gain. Depending on the task at hand, hyphenations can readily be selected, for example with MS, bioassays etc. as required to reach the relevant information about the sample. At the same time, information is obtained for many samples in parallel. The flexibility and the unrivalled features through the planar format valuably assist separation scientists.

J. Chromatogr. B 878 (17-18), 1337-1345 (2010). Use of rabbit liver esterase, Bacillus subtilis esterase, and cutinase from Fusarium solani pisi for the detection of 21 organophosphorus and carbamate pesticides by HPTLC-enzyme inhibition assays (HPTLC-EI) on silica gel with n-hexane - ethyl acetate - dichloromethane 13:4:3. HPTLC-EI assay of three groups of organophosphate and carbamate insecticides with 1) n-hexane - ethyl acetate 63:37, 2) chloroform - ethyl acetate 9:1, 3) n-hexane - acetone - dichloromethane 15:2:3. Detection by treatment with Fast Blue Salt B and enzymatically coupling to alpha-naphthol released from the respective acetate used as substrate. Quantification by densitometry at 533 nm. Calculation of enzyme inhibition factors derived from HPTLC-EI using linear calibration curves. Comparison to published inhibition constants showed good correlation. The limits of detection ranged from a few pg/zone for organophosphates as strongest inhibitors to a few ng/zone for most carbamates and was around 60 ng/zone for chlorpyrifos and 14 ng/zone for parathion without oxidation. The CUT was able to detect insecticides of high and low inhibitory power in the range of ng to µg/zone. The HPTLC-EI with rabbit liver esterase was applied to the analysis of apple juice and drinking water samples spiked with paraoxon (0.001 mg/L), parathion (0.05 mg/L) and chlorpyrifos (0.5 mg/L). The mean recovery was 71-112 % with standard deviations of 2.0-18.3 %.

Talanta, 80 (5), 2007-2015 (2010). Presentation of a method for determination of oxybutynin hydrochloride (OX) in presence of its degradation product and additives in its pharmaceutical formulations. UV spectrophotometry using the first derivative of ratio spectra and measurment at 216 nm. Chemometric analysis using principal component regression and partial least-squares. HPTLC of OX and its degradation products methylparaben and propylparaben on silica gel with chloroform - methanol - ammonia - triethylamine 500:15:2.5:1. Quantitative determination by densitometry at 220 nm. Comparison of the results obtained with all three methods showed no significant differences.

Anal. Chim. Acta 690 (2), 148-161 (2011). Chromatographic fingerprinting has been generally accepted as analytical method for the quality control of herbal medicines. This review describes the evolution of the regulations and guidelines on the quality control of herbal medicines, and reviews the established analytical techniques in TLC, HPLC, UHPLC, hydrophilic interaction chromatography, and GC. Emphasis is put on the most recent developments, such as miniaturized techniques, new stationary phases, analysis at high temperatures and multi-dimensional chromatography. The new chemometric data handling techniques are discussed.

CBS 106, 5-6 (2011). HPTLC on 1) ProteoChrom silica gel with 2-butanol – pyridine – ammonia 25 % – water 39:34:10:26; on 2) ProteoChrom cellulose with 2-butanol – pyridine – acetic acid – water 15:10:3:12 by two-dimensional development and on 3) silica gel with the developing solvent from 2). Detection by spraying with ninhydrin, fluorescamine, or triethylamine reagent. Evaluation under daylight and UV 366 nm. Detection by mass spectrometry by scanning the plate with a self modified desorption electrospray beam. In one-dimensional HPTLC up to 20 bands can be separated. By two-dimensional separation this number can be increased. Particularly suited are cellulose HPTLC plates.