J. Planar Chromatogr. 22, 297-300 (2009). HPTLC of chlorogenic acid and of plant extracts on silica gel with ethyl acetate - formic acid - water 10:2:3 and ethyl acetate - formic acid - acetic acid - water 100:11:11:21 in a saturated horizontal chamber. Quantitative determination by absorbance measurement at 320 nm. Qualitative detection by derivatization with natural products reagent (1 % in methanol) followed by treatment with 5 % PEG 400 in ethanol.

60th Indian Pharmaceutical Congress PG-349 (2008). HPTLC of 3H-4M-benzaldehyde (in crude plant material, extracts and dosage form of Hemidesmus indicus) on silica gel with toluene - ethyl acetate - methanol - acetic acid 15:3:1:1. Quantitative determination by absorbance measurement at 230 nm.

J. Planar Chromatogr. 23, 230-232 (2010). HPTLC of (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, (-)-epigallocatechin gallate, (-)-epicatechin gallate, procyanidin B2, procyanidin A2, and methylxanthines (theobromine and caffein) on cellulose with n-propanol - water - acetic acid 20:80:1 in a horizontal chamber. Detection by dipping for 1 s into 4-dimethylaminocinnamaldehyde detection reagent. Quantitative determination by absorbance measurement at 655 nm. By densitometry LOD for (-)-epicatechin and procyanidin B2 was 0.2 and 2 ng/zone, respectively; LOQ was 0.4 ng and 4 ng/zone, respectively. These limits were lower by a factor 50 for (-)-epicatechin and by a factor of 10 for procyanidin B2 than those obtained by HPLC. The TLC method gave a more accurate result for the (-)-epicatechin content of baking chocolate than the HPLC method which was also more time-consuming.

J. Planar Chromatogr. 23, 184-189 (2010). Multidimensional planar chromatography on monolayer or multiphase plates and modern fiber optical TLC densitometer scanners with DAD is especially useful for correct identification of components of difficult, complicated mixtures, e.g. pesticides in plant extracts (after preliminary clean-up and concentration by, e. g., solid-phase extraction). TLC of clofentezine [3,6-bis(2-chlorophenyl)-1,2,4,5-tetrazine] in Herba Thymi on silica gel in a horizontal chamber with tetrahydrofuran - n-heptane 3:7 in the first direction, then with ethyl acetate - n-heptane 1:4 in the second direction. Detection in the range of 200 to 600 nm with a TLC-DAD scanner. Also TLC of thyme herb extracts on silica gel and on RP18 plates with tetrahydrofuran - n-heptane 3:7 in the first direction and with methanol - water 7:3 in the second direction. LOD and LOQ were 0.23 and 0.70 µg/band, respectively, in TLC-DAD and 0.35 and 1.06 µg/mL, respectively, in HPLC-DAD. Average recoveries from the spiked plant material samples were 80.1 % and 100.5 % at 2.5 µg/g and 95.1 % at 5 µ/g measured at 202 nm.

J. Liq. Chromatogr. Relat. Technol. 31, 2429-2441 (2008). TLC of citalopram, sertraline, fluoxetine, and fluvoxamine on silica gel with acetone - benzene - 25 % ammonia 10:9:1 in a twin-trough chamber saturated for 15 min. Detection under UV 254 nm. The hRf value was 28 for fluoxetine, 44 for citalopram, 56 for fluvoxamine, and 68 for sertraline (with a standard deviation less than 0.02 % in all cases). Quantitative determination by absorbance measurement at 240 nm. The calibration curve was linear in the range of 500-5000 ng/spot for all analyzed compounds; correlation coefficients were found to be more than 0.998 for all drugs (except the 0.991 for fluvoxamine). LOD was 40 ng/spot for citalopram and 50 ng/spot for fluoxetine, fluvoxamine, and sertraline, respectively. LOQ was found to be 130 and 160 ng/spot for citalopram and fluoxetine, respectively. Intra-assay precision (% RSD) was within the range of 0.52-0.87 % and 1.34-1.84 % for citalopram and fluoxetine, respectively, inter-day precision for the analyses conducted on three consecutive days was below 1.8 % and 2.5 % for citalopram and fluoxetine, respectively. The recoveries (RSD) of citalopram ad fluoxetine were found to be in the range of 99.3-100.3% (0.8 %) and 99.4-100.4 % (1.9%), respectively.

Abstract No. C-497, 61st IPC (2009). HPTLC of ellagic acid in seeds of Eugenia jambolana Lam on silica gel with ethyl acetate - glacial acetic acid - formic acid - water 100:11:11:27. Densitometric evaluation at 254 nm. The method was linear in the range of 200-1200 ng/band. The alcoholic seed extract contained 11.03 % of ellagic acid and 21 % of total tannin (measured by chemical method).

Abstract No. C-291, 61st IPC (2009). Quantitative determination of curcumin in the marketed herbal product Rheumax (Herbajules rumatis) containing extracts of Curcuma longa, Boswellia serrata, Tinospora cordifolia and Vitex negundo by TLC on silica gel with chloroform - methanol 37:3. The hRf value of curcumin was 59. Quantitative absorbance measurement at 430 nm. The linear regression between 100 and 500 ng/zone showed R2 of 0.99984 and RSD of 1.58 % for curcumin.

J. Chromatogr. A 1217(1), 99-103 (2010). Discussion of the definition of multidimensional (MD) separations, especially some potentially powerful separation techniques such as comprehensive 2D LC (LC × LC), and comprehensive 2D GC (GC × GC). The definitions of MD separations have been extended by some researches beyond their intended scope. This disqualifies comprehensive 2D techniques as LC × LC, GC × GC and 2D TLC from being considered as 2D techniques. In other instances, extended treatment of the definition is used as a basis to justify design-parameters of comprehensive 2D separations despite the fact that these parameters lead to sub-optimal implementations. The review draws attention to the shortcomings in the definition, discusses the weaknesses in the currently used definitions, and proposes to define n-dimensional analysis as one that generates n-dimensional displacement information.