International Journal of PharmTech Research 3(2), 986-999 (2011). TLC of methanolic extracts of Haritaki and gallic acid and rutin as markers on silica gel with toluene - ethyl acetate - formic acid 3:6:1 for gallic acid and chloroform - ethyl acetate - methanol - formic acid 7:10:1:2 for rutin. Quantitative determination by densitometry in absorbance mode at 280 nm for gallic acid and 254 nm for rutin. The method was linear in the range of 100-500 ng/band for gallic acid and 1000-5000 ng/band for rutin. The recovery was 99.1 % for gallic acid and 97.9 % for rutin. The LOD and LOQ of gallic acid was 71 and 213 ng/zone and of rutin 63 and 189 ng/zone.

J. Planar Chromatogr. 24, 394-399 (2011). TLC of leave extracts and six flavonoids as markers (vitexin, isovitexin, orientin, isoorientin, quercetin, and tricin) on silica gel, prewashed with methanol and methylene chloride, with methanol - ethyl acetate - acetone - methylene chloride in different ratios using automated multiple development. The developed plate was dried in air for 2 h and sprayed with 1 % aluminum trichloride in ethanol. Then the plate was left for 2 h for derivatization in a glass drying chamber. Quantitative determination by densitometry at 366 nm. The hRf values of the six marker flavonoids were 22, 31, 38, 45, 57, and 88, respectively. Linearity was between 175 and 1750 ng/band. Instrument precision (n = 10) was between 0.2-0.9 %. The repeatability for standards and samples (n = 9), was 0.7 and 0.5, 0.8 and 0.5, 0.8 and 0.5, 0.8 and 0.4, 1.3 and 0.7, 1.1 and 0.3 % for isoorientin, orientin, isovitexin, vitexin, quercetin, and tricin, respectively. The limits of detection were 35, 40, 35, 50, 80, and 20 ng/zone for isoorientin, orientin, isovitexin, vitexin, quercetin, and tricin, respectively. The intra-day and inter-day precision was between 0.1-2.9 % and 0.3-2.4 % for all six marker flavonoids.

J. Planar Chromatogr. 24, 35-39 (2011). HPTLC of olmesartan medoxomil (OLM) and hydrochlorothiazide (HTZ) on silica gel with chloroform - methanol - formic acid 16:3:1 in a chamber saturated for 1 h. Detection under UV light at 254 nm. Quantitative determination by densitometry at 260 nm for olmesartan medoxomil and 272 nm for hydrochlorothiazide. Linearity was between 0.05-1 mg/mL. Average recovery was 100.3 % and 99.9 % for OLM and HTZ, respectively. The LOD was 138 and 137 ng/zone for OLM and HTZ, respectively, and the LOQ was 459 and 456 ng/zone for OLM and HTZ, respectively. The intra-day and inter-day precision (%RSD, n = 9) was 1.2 and 1.4 % for OLM and 1.1 and 1.3 % for HTZ.

J. Planar Chromatogr. 24, 253-256 (2011). HPTLC of yohimbine on silica gel, prewashed with methanol, with toluene - ethyl acetate - diethyl amine 7:2:1 in a twin trough chamber saturated with mobile phase for 10 min at 25 +/- 2 °C. Quantitative determination by densitometry in absorbance mode at 285 nm. Linearity was between 400 and 1200 ng/band. The hRf value was 39. The repeatability as system precision and method precision (n = 6) was 0.9 and 0.8 % CV. The limit of detection and quantification was 80 ng and 260 ng. The instrument precision (n = 6), intra-day and inter-day precision (n = 3, %RSD) were 0.2, 0.1, and 0.1 %, respectively.

J. Planar Chromatogr. 24, 482-486 (2011). HPTLC of (-)-epicatechin and procyanidin B2 in chocolates on cellulose with n-propanol - water - acetic acid 20:80:1. Detection by immersion for 1 s in 4-dimethylaminocinnamaldehyde. Quantitative determination by densitometry at 655 nm. The samples contained 13 mg/100 g each of (-)-epicatechin and procyanidin B2 with a relative standard deviation of 5.8 and 4.2 % (n = 6), respectively. The calibration curves were polynomial in the range of 2-30 ng/zone for (-)-epicatechin and 4-60 ng/zone for procyanidin B2. LOD was 0.2 ng/zone (0.7 pmol) and 2 ng/zone (3.5 pmol) as well as LOQ was 0.4 ng/zone (1.4 pmol) and 4 ng/zone (7 pmol) for (-)-epicatechin and procyanidin, respectively.

J. Planar Chromatogr. 24, 222-226 (2011). HPTLC of lamotrigine in human serum with chloramphenicol as internal standard on silica gel, prewashed with methanol, with ethyl acetate - methanol - 32 % aqueous ammonia 17:2:1 in a saturated twin-trough chamber. Quantitative determination by densitometry at 280 nm. The hRf of lamotrigine was 37. Linearity was between 0.6 and 300 ng/band, corresponding to 0.06-30.00 ng/µL lamotrigine in human serum after extraction and application of 1 µL to the chromatographic plate. The correlation coefficient was 0.998. Intra-assay and inter-assay precision (%RSD) were in the range of 0.5-2.9 % (n = 3) and 1.6 -2.9 % (n = 9), respectively. LOD and LOQ were 16 and 42 pg/zone, respectively. Recovery (by standard addition) was between 94.1-101.3 %, with %RSD not higher than 3.5 %.

J. Planar Chromatogr. 24, 30-34 (2011). TLC of ceftriaxone sodium on RP-18 with 15 % ammonium acetate buffer (pH 6.2) - methanol - acetonitrile 48:2:1 after saturation of the chamber for 20 min. Detection under UV light at 254 nm. Quantitative determination by densitometry in absorbance mode at 302 nm as well as by use of TLC-image analysis. Linearity was between 1-8 µg/zone. LOD and LOQ were 228 and 759 ng/zone, respectively. The hRf value of ceftriaxone sodium was 58.

J. AOAC Int. 93, 778-782 (2010). TLC of mirtazapine and mianserine in tablets on silica gel with n-hexane - isopropanol - 25 % ammonia 70:25:59. Quantitative determination by absorbance measurement at 280 nm. Calibration curves were linear (r2 > 0.9970) with respect to peak area in the concentration range of 500-2500 and 500-5000 ng/zone for mirtazepin anf mianserine, respectively. The LOD was 20 and 35 ng/zone for mirtazepin and mianserine, respectively. LOQ was 50 and 85 ng/zone for mirtazepin and mianserine, respectively. The instrumental precision (%RSD; n = 6) was 0.3 and 0.2 %, the repeatability of standards (%RSD; n = 6) was 0.4 and 0.5 % for mirtazepin and mianserine, respectively. The recovery values were found to be 101.2 % for mirtazepin and 99.8 % for mianserine.