Detection under UV 254 nm. Quantification by UV spectrophotometry at 240 nm.

Anal. Bioanal. Chem. 387, 1083-1093 (2007). A new HPTLC method for trace analysis (low µg/kg range) of the five heterocyclic aromatic amines PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine), MeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline), 4,8-DiMeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline), norharmane (9H-pyrido[3,4-b]indole) and harmane (1-methyl-9H-pyrido[3,4-b]indole) in meat samples has been established. HPTLC on LiChrospher silica gel WRF with methanol – chloroform 1:9. Using the ADC2, the plate activity was adjusted to 34 % relative air humidity with MgCl2 x 6H2O for 15 min and, at the same time, chamber saturation with 35 mL aqueous ammonia 28 % – ultrapure water 1:4 was performed for 20 min, followed by alkaline plate preconditioning for 15 min. The development was performed in a fresh chamber. Quantitative determination by absorbance measurement at UV 262 nm and 316 nm, and fluorescence measurement at UV 366/>400 nm. The UV wavelength 316 nm was later substituted by 313/>340 nm for a more selective and sensitive determination of PhIP in the meat matrix. Mass spectrometric analysis was performed in ESI+ mode for confirmation of positive findings. The method was validated according to ICH guidelines. Repeatability was better than 3.3 % (n=14), the intermediate precision (n=6, peak area) was 0.4 % (PhIP), 0.6 % (MeIQx), 0.7 % (4,8-DiMeIQx), 0.9 % (norharmane) and 1.1 % (harmane). Reproducibility of the migration distance was better than 1.3 % (n=6). LODs were 4 ng/band for PhIP, 5 ng/band for MeIQx, 4 ng/band for 4,8-DiMeIQx, and 0.4 ng/band each for norharmane and harmane. LOQs were 6 ng/band for PhIP, 14 ng/band for MeIQx, 11 ng/band for 4,8-DiMeIQx, and 0.8 ng/band each for norharmane and harmane. Selectivity in the meat matrix was proven. Confirmation of the substances found in meat was performed by MS. In the working range RSDs of the calibration functions were between 1.9 and 3.6 %.

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 %.

62nd Indian Pharmaceutical Congress Abstract No. F-250 (2010). TLC of risperidone on silica gel with methanol – ethyl acetate 4:1. The hRf value was 34. Quantitative determination by absorbance measurement at 254 nm. The method was linear in the range of 100-600 ng/band. The proposed method was employed for estimation of solubility equilibrium, analysis of mucoadhesive microemulsion formulations and in vitro diffusion studies.

J. Planar Chromatogr. 26, 209-214 (2013). HPTLC of pioglitazone hydrochloride on silica gel with chloroform - methanol 10:1. Detection by spraying with 0.5 % o-phthalaldehyde in ethanol, followed by heating at 70 ºC for 15 min. Quantitative determination by scanning with a flatbed scanner and a gel analysis software. Linearity was in the range of 200-3000 ng/zone. LOD and LOQ were 65 and 197 ng/zone, respectively. Recovery was in the range of 98-102 %. Intermediate/interday/intra-day precision was below 2 %.

J. Chromatogr. 320, 281-291 (1985). Reversed-phase TLC of a series of nitroimidazo(2 1-6)thiazoles on silica impregnated with 5 % solution of silicone oil, with glycocoll buffer (0.1M) of pH 13 alone or in various mixtures with acetone or methanol. Determination of RM values. Correlation of extrapolated RM and log k' obtained by HPLC with Hansch values for the derivatives. Discussion of the correlation of their structure with mutagenic activity.

Acta Pharmaceutica Jugoslavica 39, 1-16 (1989). TLC of 8-hydroxyquinoline analogues and 5-nitro-8-hydroxyquinoline on silica with chloroform, chloroform - ethyl acetate 8:2, chloroform - methyl salicylate 9:1, chloroform - amylalcohol 9:1, chloroform - methanol 9:1, benzene - methanol 9:1, ethyl acetate - methanol - acetic acid 15:10:4, ethanol, propanol - water 7:3, NH3 conc. - methanol 1. 5:100, 2. 5:100, 3. 5:100, 4. 5:100, 5. 5:100 and 6. 5:100. Detection under UV 254 nm.

J. Planar Chromatogr. 5, 468-469 (1992). TLC of thioquinanthrene and thioquinanthrene-7-oxide on silica with chloroform - methanol 19:1. Visualization under UV 254 nm. Quantification of the sulfoxide after elution by photometry.