J. of Qilu Med. & Pharm. 29(11), 658-659 (2010). TLC on silica gel with 1) benzene – methanol 27:1; 2) toluene – methanol 17:1 ; 3) cyclohexane – propanone 10:3:4) petroleum ether (60-90 ºC) – ethyl acetate – formic acid 85:15:2, or 80:20:1. Detection by spraying with 1 % vanillin in sulfuric acid and heating at 100 °C until the zones were visualized. Identification by comparison of the fingerprint with the characteristic reference standards magnolol and honokiol. System 4) provided the best separation.

Journal of Environmental Science and Health, Part B 46, 557-568 (2011). Review on techniques and applications of TLC and HPTLC for separation, detection, qualitative and quantitative determination and preparative isolation of pesticides. Covered are sample preparation techniques, stationary phases, sample application, mobile phases, development methods using different chambers, detection under UV or by derivatization with various reagents, identification based on hRf values or by online HPTLC-MS, quantification by scanning densitometry or videodensitometry, preparative layer chromatography and thin-layer radiochromatography. Various applications are described. In the review period especially forensic analyses of human and animal samples for pesticides were numerous. The identification and quantification of components from plant extracts with pesticide activity is also reviewed and it is expected that this area will be especially active in the future given the large amount of ongoing worldwide research on phytochemical compounds.

CBS 107, 13-15 (2011). HPTLC of 5-hydroxymethylfurfural (HMF) in honey on silica gel, prewashed with methanol - water 6:1, with ethyl acetate. Quantitative determination by densitometry in absorbance mode at 290 nm. Optional detection by immersion in p-aminobenzoic acid reagent followed by heating at 110 °C for 5-10 min. The hRf value of HMF was 80. The calibration function was polynomial in the range of 0.8-80 ng/band whilst Michaelis Menten 2 regression was suitable for higher concentrations. The LOD of HMF in honey samples was 0.75 mg/kg (12 µL applied) and the LOQ 2.4 mg/kg. The method complies with the requirement of max. 15 mg/kg of HMF in honey. The results with this method were compared with those obtained by the spectrophotometric Winkler method and by HPLC-UV and mean differences were minor (3.3 % or 0.9 mg/kg). Complementary confirmation by HPTLC-MS online coupling. HMF zones identified under UV were eluted and analyzed by ESI-MS in full-scan and SIM mode.

Asian Journal of Chemistry 23(10), 4351-4354 (2011). HPTLC of nateglinide in tablet dosage form on silica gel with n-hexane - methanol - isopropanol 75:15:10. The hRf value was 56. Quantitative evaluation by absorbance measurement at 210 nm. The method was linear in the range of 300-1000 ng/band. The average recovery was 98.5 %.

J. Planar Chromatogr. 24, 248-252 (2011). TLC of MGDG and DGDG on silica gel with chloroform - methanol -10 % acetic acid 40:10:1. Detection by spraying with a 25 % solution of sulfuric acid in methanol, followed by heating at 105 °C for 5 min. Quantitative determination by densitometry at 477 nm. The hRf values were 48 for DGDG and 80 for MGDG. The limit of detection and quantification was 200 and 500 ng/band for DGDG and 500 and 1500 ng/band for MGDG. The linear range was 0.5-5.5 µg/band for DGDG and 1.5-5.5 µg/band for MGDG, respectively. The recovery (n= 9) was 95.7 % for DGDG and 93.5 % for MGDG. The repeatability and intermediate precision of results, as %RSD, was between 1.7-2.7 % for DGDG and 1.7-2.6 % for MGDG.

ex Schultes. J. Planar Chromatogr. 24, 388-393 (2011). HPTLC of p-hydroxybenzoic acid in the whole plant of Aerva lanata collected during summer, monsoon and winter on silica gel, prewashed with methanol, with ethyl actate - toluene 7:3 in a twin trough chamber. Detection under UV light at 254 nm. The hRf value of p-hydroxybenzoic acid was 73. Quantitative determination by densitometry at 252 nm. The calibration was linear in the range of 25-175 ng, with a regression coefficient of 0.9986. The %RSD for intra-day and inter-day precision was less than 2 %. The %RSD for the repeatability of sample application and measurement of area was 1.2 % and 0.9 %, respectively. The limit of detection and the limit of quantification was 0.5 and 1.4 ng, respectively. Recovery (by standard addition) was found to be 97.2 % (n = 3).

J. Planar Chromatogr. 24, 497-502 (2011). HPTLC of isoswertisin-5-O-beta-D-glucoside (1), swertiamarin (2), and swertisin (3) as biomarkers on silica gel with ethyl acetate - methanol - water 16:2:1 in a twin-trough chamber with saturation for 30 min. Quantitative determination by absorbance measurement at 287 nm. Linearity was between 25-75 µg/mL for (1), 200-600 µg/mL for (2), and 100-300 µg/mL for (3). The relative standard deviation for instrumental precision, intra-assay precision, and intermediate precision was below 2 %. The average recovery was 99.9 % for (1), 99.6 % for (2), and 99.1 % for (3). The hRf values were 32 for (1), 41 for (2), and 52 for (3). The limit of detection was 570 ng, 740 ng, and 300 ng for (1), (2), and (3), respectively.

J. of Chromatogr. A 1218 (33), 5693-5704 (2011) A micro-TLC platform for the fast analysis of low-molecular mass compounds from spirulina samples was developed. The target compounds were extracted with methanol, acetone or tetrahydrofuran. HPTLC on RP-18W with acetone - n-hexane 3:7 in an unsaturated chamber using a temperature controlled micro-planar chromatographic device based on a horizontal chamber. Detection under visible light before and after exposure to iodine vapor. Pictures of the chromatograms were acquired with an office scanner and digitalized. The quantitative data was analyzed using cluster analysis and principal components analysis. With this method it was possible to distinguish genuine spirulina and non-spirulina samples as well as fresh and expired commercial products.