Chinese J. Ethnomed. Ethnopharm. (23), 61-64 (2010). Optimization of the sample preparation procedure for Herba Saururi chinensis 1) by ultrasonication with methanol for 60 min; 2) by ultrasonication with methanol for 20 min and filtration through neutral alumina column with methanol; 3) by reflux extraction with 80 % methanol for 60 min and extraction with diethyl ether; 4) by ultrasonication with ethanol for 60 min; 5) by ultrasonication with methanol - 25 % hydrochloric acid 4:1 for 60 min and extraction with ethyl acetate. Procedure 5) was best suited. TLC on silica gel 1) with petroleum ether (60-90 °C) – acetone 5:2, and detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 ºC until the zones appear; 2) with toluene – ethyl acetate – formic acid 5:2:1, and detection by spraying with 1 % AlCl3 in ethanol and evaluation under UV 366 nm; 3) with n-hexane – ethyl acetate – formic acid 70:50:8, and detection by spraying with 1 % AlCl3 in ethanol, heating at 105 ºC and evaluation under daylight or under UV 366 nm; 4) with toluene – ethyl acetate – formic acid 5:4:1 with chamber saturation with hydrochloric acid vapor, detection under daylight or UV 366 nm.

CBS 107, 9-10 (2011). Extraction of pesticides from fruit and vegetable samples by QuEChERs method. TLC of acetamiprid, azoxystrobin, chlorpyriofos, fenarimol, mepanipyrim, penconazole and pirimicarb on amino phase aluminum foil (prewashed with acetonitrile) with acetonitrile over a migration distance of 75 mm in the first direction. After drying development in the backwards direction over 45 mm with acetone. Evaluation under UV 254 nm, UV 366 nm, white light and under UV 366 nm after immersion in primuline solution. Extraction of the target zone by TLC-MS interface with acetonitrile - 10 mM ammonium formate 1:1. Average recoveries of the seven pesticides were 90-104 % with %RSD of 0.3-4.1 % (n = 5). This new high-throughput planar solid phase extraction method for multi-residue analysis of pesticides in food allows a rapid and efficient clean-up at low costs and low solvent consumption.

International Journal of ChemTech Research 2(3), 1372-1375 (2010). TLC of olopatadine hydrochloride on silica gel aluminum foil with methanol - water - glacial acetic acid 40:10:1 with chamber saturation for 20 min. The hRf value was 37. Quantitative determination by densitometry in absorbance mode at 247 nm. The method was linear in the range of 200-1200 ng/band. The average recovery was 100.5 %.

J. of Chromatogr. A 1218 (20), 3089-3084 (2011). Comparison of the separation of the structurally related angiotensin-converting enzyme (ACE) inhibitors lisinopril, cilazapril, ramipril and quinapril and their corresponding active diacid forms (prilates) by conventional TLC on silica gel with the separation on monolithic ultra-TLC (UTLC) phase. Technical modifications of the commercially available equipment for sample application, development and detection were necessary for the use with UTLC plates. Development in a modified horizontal developing chamber with ethyl acetate - acetone - acetic acid - water 16:4:1:2. Detection by absorbance measurement at 220 nm and after exposure to iodine vapors under daylight, as well as by image analysis. As a result the monolithic layer was more efficient for the separation of structurally similar polar compounds, such as prilates, than conventional silica layers. Confirmation of the identity of the compounds by ESI-MS after their online extraction from the UTLC and TLC plates.

J. Liq. Chromatogr. Relat. Technol. 34, 1850-1869 (2011). HPTLC of pipazethate (1) and its degradant 10H-pyrido[3,2-b][1,4] benzothiadiazine-10-carboxylic acid (2) on silica gel with chloroform - diethylamine - methanol 94:1:5. Quantitative determination by absorbance measurement at 225 nm. The hRf values of (1) and (2) were 35 and 28, respectively. Linearity was between 2-9 µg/zone for (1) and 1-6 µg/zone for (2). Limits of detection and quantification were found to be 53 and 180 ng/zone for (1), and 40 and 130 ng/zone for (2), respectively. Recoveries (by standard addition) were 100.1 % for (1) and 99.5 % for (2). Comparable results were obained with a validated HPLC method.

J. Planar Chromatogr. 24, 121-124 (2011). HPTLC of kurarinone and sophoraflavanone G in the roots of Sophora flavescens on silica gel with chloroform - methanol 10:1 with chamber saturation for 30 min at 20 °C. Quantitative determination by absorbance measurement at 285 nm. The intra-day and inter-day %RSD were 1.9-2.0 % and 2.2-2.4 %, respectively. Instrument precision and repeatability of the method were 0.4-0.6 and 1.81-1.84 %, respectively. Average recovery was 96.3-103.4 % for kuraninone and 96.8-102.9 % for sophoraflavanone G. The limits of detection and quantification were 27 and 80 ng/band for kurarinone and 12 and 36 ng/band for sophoraflavanone G. Linearity was in the range of 200-1200 ng/band for kurarinone and 90-550 ng/band for sophoraflavanone. The hRf value was 31 and 50 for kurarinone and sophoraflavanone, respectively.

J. AOAC Int. 94, 1094-1099 (2011). TLC of caffeine and paracetamol in capsules and tablets on silica gel with n-hexane - ethyl acetate - ethanol 25:15:4. Detection at 254 nm. Quantitative determination by densitometry at 254 and 270 nm. The hRf value of caffeine and paracetamol was 48 and 73, respectively. Linearity was between 0.2-1.9 for caffeine and 0.03-1.5 µg/L for paracetamol. The detection limit of caffeine was 25 ng/L and of paracetamol 32 ng/L. The precision was 1.9 % (n=6). Recovery (by standard addition) was 98-99.5 % for both compounds.

CBS 107, 11-12 (2011). HPTLC of tiliroside on silica gel with ethyl acetate - formic acid - acetic acid - water 100:11:11:27 + 1 % heptane. For quantification determination by densitometry in absorbance mode at 315 nm. For side component analysis detection by spraying with natural products reagent and evaluation under UV 366 nm, and by spraying with anisaldehyde reagent followed by heating for 15 min at 90-125 °C and evaluation under white light. The presence of relevant side components (e.g., coumaric acid, kaempferol and glucose) could be excluded.