Appl. Surf. Sci. 252, 6746-6749 (2006). To show the application of direct time-of-flight secondary ion mass spectrometry (ToF-SIMS) to analyze a reaction mixture between an alpha-bromoamide (1), and picolylamine, to form the substitution product (3) via SN2 (1 and 3 are indistinguishable by TLC on silica gel with dichloromethane – methanol – ammonia 100:15:2), a series of organic halides with widely differing structures (trifluoromethanesulfonamide, a vinyl bromide, a silyl-protected primary bromide, and iodosobenzene diacetate) were separated on TLC plates under the same conditions. The resulting spots and background were analyzed by positive and negative ion spectra. In all cases, the halide signals were notably stronger than the background signals. In addition, a series of amines (1,1-carbonyl diimidazole, norepinephrine, adenosine, and cinchonidine) was separated on TLC plates and analyzed directly by ToF-SIMS. In all but one (adenosine), even quasi-molecular ions were observed.

J. Chinese Trad. Patent Med. (Zhongchengyao) 27 (8), 938-941 (2005). TLC on silica gel with ethyl acetate - water - formic acid 10:1:1. Detection under UV 254 nm. Quantification of aristolochic acid l and ll by HPLC with gradient elution. Results are given for six batches of real life samples.

Tetrahedron 63, 5460-5469 (2007). Preparative TLC of branched oligoamides derived from methyl salicilate on silica gel with dichloromethane – acetone 3:1. Detection under UV 254 nm. Dimerization increases the hRf value from 12 to 46.

J. Chinese Trad. Patent Med. (Zhongchengyao) 29 (2), 217 0 221 (2007). TLC of the extracts of Anxinkang dropping pills on silica gel with 1) chloroform - methanol - ammonia 25:3:1; 2) petroleum ether (60 - 90 ºC) - ethyl acetate 20:1; 3) ethyl acetate - acetone - methanol 5:5:1. Detection 1) by spraying with 10 % potassium iodobismuthate solution; 2) by spraying with 5 % p-diethylaminobenzaldehyde in 10 % H2SO4 in ethanol, and heating at 105 °C for 10 min; 3) by spraying with 10 % H2SO4 in ethanol and heating at 105 °C. Identification by comparison with standard.

J. Liq. Chromatogr. & Relat. Technol. 30, 1385-1400 (2007). TLC of alpha-tocopherol acetate, alpha-tocopherol, cholecalciferol, estradiol, testosterone, and hydrocortisone on silica gel, silica gel and kieselguhr, and aluminium oxide after prewashing with methanol; TLC of lipophilic vitamins on silica gel with toluene, and on RP-18 with methanol both with chamber saturation. Densitometric measurement at UV 254 nm. The resulting densitograms of the compounds studied indicate that applied sorbents have an influence on the wavelength of the obtained fundamental absorption band and the additional absorption bands, as well as on their intensity values.

J. Planar Chromatogr. 20, 267-274 (2007). Comparison of retention factors in pure water, log kw, determined by linear extrapolation and by a numerical method based on Oscik’s equation, and calculated values of log P as hydrophobicity indices for nine homologues s-triazines. The effect of mobile phase pH on solute retention was investigated as well as the effect of mobile and stationary phase properties on chromatographic behavior; 3 different organic modifiers (dioxane, acetonitrile, and tetrahydrofuran) and two stationary phases (RP-8 and RP-18) were used. Correlations of calculated log P values and log kw with carbon number confirm the usefulness of chromatographic techniques for studying the hydrophobicity of organic compounds. TLC on RP-18 with buffer - methanol mixtures in saturated sandwich chambers. Detection under UV light at 254 nm.

Chromatographia 66 (11-12), 605-608 (2007). HPTLC of both isomers of cefpodoxime proxetil on silica gel plate with toluene - acetonitrile 3:2. Quantification by densitometry at 234 nm. The limit of detection and quantification was 150 and 400 ng/zone, respectively.

Indian J. Pharm. Educ. Res. 41(3), 261 (2007). HPTLC of irbesartan on silica gel with toluene - ethyl acetate - acetic acid 70:30:2. Densitometric aevaluation at 305 nm. Linearity was between 500-6000 ng/zone. Limit of detection and quantification was 100 and 400 ng/zone, respectively. Recovery was more than 100 %. The degradation products as result of acid and alkali hydrolysis, oxidation, dry and wet heat treatment and photodegradation were well separated from tirbesartan.