CBS 100, 2-5 (2008). HPTLC of photodegraded UV filters and sunscreen on silica gel LiChrospher prewashed with methanol. AMD 2 development of UV filter standards photodegradation products with diisopropylether - n-hexane in 6 steps over 50 mm without preconditioning, and of sunscreen samples photodegradation products with t-butylmethylether - n-hexane in 7 steps over 50 mm with preconditioning, followed by drying at 120 °C for 30 min. Detection at 254 and 366 nm, followed by biodetection via dipping the plate in a Vibrio fischeri solution for 1 s and evaluation with the Bioluminizer (exposure time 55 s). Densitometric evaluation by multi-wavelength scan at 200-400 nm.

J. Planar Chromatogr. 21, 103-106 (2008). HPTLC of (-)-epicatechin, (+)-catechin, (-)-epigallocatechin, (-)-gallocatechin, (-)-catechin gallate, and (-)-epicatechin gallate on RP-18 at room temperature and 75 % relative humidity in an automated development chamber with methanol - water - formic acid 30:70:6. Detection by spraying with diazotized sulfanilic acid. Quantitation by densitometry at 440 nm.

J. Liq. Chromatogr. Relat. Technol. 31, 1857-1870 (2008). HPTLC of phospholipids (phosphatidic acid, phosphatidylcholin, phosphatidylethanolamine, phosphatidylinositiol, lysophosphatidic acid, lysophosphatidylcholine, lysophosphatidylethanolamine, and lysophosphatidylinositol) on silica gel with chloroform - methanol - water - 25 % ammonia 60:34:4:2 in a twin-trough chamber saturated for 20 min. Plates were conditioned to 47 % relative humidity. Detection by dipping for 6 s in modified copper sulfate reagent (20 g copper (II) sulfate pentahydrate were dissolved in 200 mL of cooled methanol, then under cooling 8 mL of sulfuric acid 98 % and 8 mL of ortho-phosphoric acid 85 % were added) followed by drying in cold air for 30 s and heating at 140 °C for 30 min. Quantitative determination by absorbance measurement at 360 nm, 420 or 720 nm, or by video densitometry. Investigation of several parameters of the chromatographic process, including chamber saturation, derivatization, plate activity, and batch to batch consistency of the plates. For reproducible results, the employed methodology must be strictly standardized.

J. Liq. Chromatogr. Relat. Technol. 31, 555-566 (2008). Five new derivatization reagents (gentian violet, methylene violet, methylene blue, malachite green, and Janus blue) were used to detect estradiol on aluminium oxide. Barton’s reagent, rhodamine B, and sulfuric acid were used as the comparative derivatization reagents. Limit of detection, detection index, modified broadening index, modified contrast index, and linearity range were determined for estradiol after derivatization with these reagents. Quantitative determination by absorbance measurement between 200 and 600 nm.

J. Liq. Chromatogr. Relat. Technol. 31, 752-762 (2008). TLC and HPTLC of nine dipeptides (gly-gly, ala-gly, pro-leu, pro-asp, pro-gly, leu-pro, ala-pro, phe-pro, val-pro) on silica gel with ethanol - dichloromethane 2:1 and methanol - dichloromethane 1:1 in a horizontal chamber saturated for 20 min. Detection by spraying with sodium azide and starch solution (25 mL aqueous starch solution, containing 2.5 g starch, was added to 20 mL aqueous sodium azide solution containing 2 g sodium azide, the mixture was adjusted to pH 5.5 with 0.1 mol/L hydrochloric acid and diluted to 50 mL with water to obtain 4 % and 5 % solution for sodium azide and starch, respectively). All solutions were prepared fresh daily. The limit of detection was 2-200 pmol/spot for the iodine azide procedure, 1-100 pmol/spot for iodine, 20-2000 pmol/spot for UV 254 nm, and 40-1000 pmol/spot for spraying with ninhydrine and drying at 110 °C .

J. AOAC Int. 91, 1162-1167 (2008). HPTLC of curcumin, demethoxycurcumin, and bisdemethoxycurcumin as standards on silica gel prewashed with methanol using chloroform - methanol 97:3 in a twin-trough chamber at 23 °C and 31 % relative humidity. Quantitative determination by absorbance measurement at 430 nm.

Asian J. Chem. 19(6), 4183-4187 (2007). HPTLC of atenolol and indapamide in tablet formulation on silica gel with toluene - ethanol - acetone - acetic acid 70:25:30:3. Quantitative determination by absorbance measurement at 266 nm. The hRf value of atenolol and indapamide was 21 and 74, respectively. The linearity range was 3.8-10.9 ng/spot and 0.2-0.6 ng/spot for atenolol and indapamide respectively. The recovery was in the range of 98.7-100.1 % for both compounds.

Chromatographia 68 (9-10), 877-880 (2008). TLC of betulinic acid in Nymphoides macrospermum on silica gel with hexane - ethyl acetate - acetic acid 700:300:3. Detection by spraying with anisaldehyde-sulphuric acid reagent. Quantification by absorbance measurement at 540 nm. Linearity was in the concentration range of 100–600 ng/spot. The method is suitable for the routine quality control of Granthika Tagara.