Chinese J. Pharm. Anal. 28 (1), 20-23 (2008). TLC of TCM drug extracts on silica gel with toluene – ethyl acetate – methanol – isopropanol – ammonia 12:6:3:3:1. Detection under UV light. The method is suitable for quality control of Baozhi pills.

60th Indian Pharmaceutical Congress PA-223 (2008). HPTLC of curcumin, demethoxycurcumin and bis-demethoxycurcumin on silica gel with chloroform - methanol 19:1. The hRf values were 25, 38, and 61 for bis-demethoxycurcumin, demethoxycurcumin, and curcumin respectively. Quantitative determination by absorbance measurement at 420 nm. The method was linear in the range of 50-400 ng/spot (curcumin), 10-150 ng/spot (demethoxycurcumin), and 5-40 ng/spot (bis-demethoxycurcumin). Recovery was in the range of 99.2-100.5 % for all three compounds.

Abstract No. F-247, 62st IPC (2009). HPTLC of nebivolol HCl and S-amlodipine besylate on silica gel (prewashed with methanol) with chloroform - toluene - methanol - acetic acid 50:20:1. The hRf value was 33 and 48 for S-amlodipine and nebivolol, respectively. Quantitative determination by absorbance measurement at 271 nm. The method was linear in the range of 500-2500 ng/band for nebivolol and 250-1280 ng/band for S-amlodipine, respectively.

J. Chromatogr. A 1217(8), 1396-1398 (2010). Sparation of enantiomers of atenolol, propranolol, and salbutamol using different loading/impregnation techniques for the Cu(II) complexes of l-proline, l-phenylalanine, l-histidine, N,N-dimethyl-l-phenylalanine, and l-tryptophan. TLC on silica gel with acetonitrile – methanol – 2 mM aqueous solution of Cu(II) 3:4:5. The different techniques were: A) using the Cu(II)-l-amino acid complex as chiral mobile phase additive, B) development of plates in solutions of Cu-complex, and C) with a solution of Cu(II)acetate as mobile phase additive for plates impregnated with the amino acids. Detection of zones by exposure to iodine vapor.

J. Planar Chromatogr. 23, 116-118 (2010). HPTLC of ochratoxin A on silica gel with toluene - ethyl acetate - formic acid 6:3:1 in a saturated chamber. Detection by spraying with ethanolic sodium bicarbonate solution (6 g sodium hydrogen carbonate, 100 mL water, 20 mL ethanol); after drying, evaluation and videodensitometry under 366 nm. The linear regression coefficient of the calibration for OTA in the concentration range 0.8 to 12 ng/zone was 0.9992. The mean recovery was 92 +- 8.9 %. Recovery from wine samples at levels of 0.5, 2, and 5 µg/L was 84, 90, and 102 %, respectively, and the respective relative standard deviations were 5.7, 8, and 7 %. LOD was 0.32 ng/spot and LOQ 0.1 µg/L.

J. Planar Chromatogr. 23, 233-236 (2010). HPTLC of trans-citral and cis-citral in lemongrass oil on silica gel with toluene - ethyl acetate 17:3 in a twin-trough chamber saturated for 15 min (at 25 °C and 55 % RH). Detection by spraying with vanillin-sulfuric acid reagent. Quantitative determination by absorbance measurement at 595 nm. Intra-day and inter-day precision were evaluated by replicate (n = 6) analysis of samples (trans-citral at 450, 900, and 1800 ng/band, and cis-citral at 470, 940, and 1880 ng/band). The linear range was 225-3600 ng/band for trans-citral, and 470-3760 ng/band for cis-citral. The correlation coefficient r was 0.9933 for trans-citral and 0.9937 for cis-citral. Intra-day precision (n = 6) was < 3.56 and 5.66 % for trans- and cis-citral, respectively. Inter-day precision was assessed to be < 3.47 and 5.52 % for trans- and cis-citral by repeating the intra-day assay on three different days. Repeatability of sample application and peak-area measurement was 0.98 %, determined by performing six replicate analyses of the same band (1800 ng/band trans-citral and 1880 ng/band cis-citral). The RSD of recovery of trans and cis-citral was in the ranges 1.36-3.25 and 1.64-3.47, respectively.

Abstract No. C-258, 61st IPC (2009). HPTLC of piperine, plumbagine and zingiberine in Panchkol Churna, an ayurvedic preparation used for anorexia, distension and abdominal pain. HPTLC on silica gel with toluene - ethyl acetate 7:3. Densitometric evaluation at 340 nm for piperine, and at 420 nm for plumbagine and zingiberine. The hRf value of piperine, zingiberine and plumbagine was 31, 75, and 84.

J. Planar Chromatogr. 23, 70-74 (2010). Descripton of a selective and simple HPTLC method for quantification of oenothein B on the basis of the free gallic acid and total gallic acid content after acid hydrolysis. HPTLC of gallic acid on silica gel with benzene - methanol - acetic acid 90:16:8 in a glass chamber previously saturated with the mobile phase vapor for 20 min. Quantitative determination by absorbance measurement at 570 nm after derivatization with 1 % ethanolic iron(III) chloride solution. Average recovery of the active ingredient was in the range 95.4-104.6 %. Linearity was in the range of 440-2200 ng/band. The correlation coefficient r was 0.9991, LOD/LOQ were120/360 ng/band; repeatability (RSD) was 3.0 % and intermediate precision 1.0 %; intraday precision (RSD, n = 6, 440-2200 ng/band) was 3.8 to 5.2 % and interday precision 4.3 to 5.7 %. Both, precision and accuracy, were within acceptable limits for routine drug analysis (</= 15 %).