J. Planar Chromatogr. 23, 137-140 (2010). HPTLC of aspirin, salicylic acid, and sulfosalicylic acid on silica gel (prewashed with methanol-chloroform 1:1 and impregnated with 2 % boric acid in ethanol) with chloroform - methanol - ammonia - water 120:75:2:6 in a chamber previously saturated at 25 °C for 30 min. Detection and quantitative determination by densitometry at 254 nm. The hRf of aspirin, salicylic acid, and sulfosalicylic acid were 81, 61, and 24, respectively. The linear range was 100-1000 ng/band for all three compounds, and the correlation coefficients r were 0.97, 0.94, and 0.95, respectively. LOQ were 123, 95, and 61 ng/band, respectively, and the respective LOD were 37, 37, and 18 ng/band.

International Seminar on Herbal Drug Research, PN-017 (2009). HPTLC of thiocolchicoside and diclofenac sodium on silica gel with toluene - acetone - methanol - formic acid 500:200:200:1. Quantitative determination by absorbance measurement at 280 nm. The method was linear in the range of 160-800 ng/band (thiocolchicoside) and 1000-5000 ng/band (diclofenac sodium). The recovery was in the range of 99.2-100.9 for both compounds.

Encyclopedia of Chromatography Third Edition 1, 950-953 (2009). The author describes the standard guides of the ASTM designations for forensic writing ink comparison and identification using TLC. Recent advances such as software for visual comparison of chromatograms are included. In addition, new applications of TLC in the field of forensic ink analysis and comparison with spectrometric and chromatographic methods are also described.

International Journal of PharmaTech Research 03, 527-538 (2009). A stability indicating HPTLC method has been developed for analysis of cephalexin in bulk and dosage formulation. HPTLC on silica gel with ethyl acetate - methanol - 25 % ammonia 6:4:1. The hRf value was 56. Densitometric quantification at 260 nm. The method was linear in range of 500-1500 ng/band. Cephalexin was subjected to forced degradation (acid, alkali, oxidation, thermal, photolytic). All degradation products were well separated from the drug, indicating specificity of the method.

J Young Pharm 1(3), 259-263 (2009). A validated HPTLC method is described for simultaneous estimation of amlodipine besylate and telmisartan in dosage form. HPTLC on silica gel with tetrahydrofuran - dichloroethane - methanol - 25 % ammonia solution 60:20:10:4. The hRf value of amlodipine besylate was 45 and of telmisartan 22. Densitometric evaluation at 326 nm. Linearity was in the range of 1200-7200 ng/band for telmisartan and 400-1400 ng/band for amlodipine besylate. The limit of detection was 149 ng/zone and 53 ng/zone for telmisartan and amlodipine besylate, respectively. The limit of quantification was 453 ng/zone for telmisartan and 161 ng/zone for amlodipine besylate. The recovery was between 100.4 and 100.8 %.

fruits rind by using high-performance thin-layer chromatography. Asian Journal of Chemistry 23(2), 788-790 (2011). A simple HPTLC method has been developed for estimation of beta-carotene in fruit rind of Diplocyclos palmatus (Cucurbitaceae). The rind of fruits was extract with acetone. HPTLC on silica gel with petroleum ether as mobile phase. The hRf value of beta-carotene was 30. Densitometric evaluation at 450 nm. The method was linear in the range of 6-60 ng/band. The recovery was 99.4 % for beta-carotene.

J. Planar Chromatogr. 23, 282-285 (2010). HPTLC of compactin and citrinin on silica gel with toluene - ethyl acetate - formic acid 3:2:1 in a twin-trough chamber saturated for 30 min at room temperature and a relative humidity of 60 +/- 5 %. Quantitative determination by absorbance measurement at 238 nm and 366 nm. The hRf of compactin and citrinin was 47 and 62, respectively. Good correlation was obtained between peak area and concentration, with a determination coefficient r2= 0.998 for compactin and 0.996 for citrinin.

J. Planar Chromatogr. 23, 286-288 (2010). TLC of taxol with a stationary-phase gradient whereby parts of different TLC plates were connected by use of a MIGAS device. Separated taxol-containing zones were developed with methanol over 1 cm and thus moved to another plate. The lipophilic substance zone was cut out after separation of the sample on a silica gel plate with n-heptane - ethyl acetate 1:1. Further separation of taxol from accompanying hydrophilic substances was carried out on HPTLC RP-18W with methanol - water 4:1. The taxol-containing fraction was finally separated on silica gel with chloroform - acetone 3:1 in a horizontal chamber at constant temperature (30 +/- 1°C) and humidity (35 +/- 1 %). Detection under UV 254 and 366 nm. Quantitative determination by densitometry at 220 nm. The precision (n = 7) was 0.63 % and the repeatability (n = 7) 3.35 %. The limit of detection and quantification was 0.50 and 1.00 µg/zone, respectively; the correlation coefficient from linear regression was >0.98, and the linear calibration range was 1 - 10 µg/zone.