J. Chromatogr. A 1473, 133-142 (2016). Development of a simple, accurate and precise method for the analysis of proton pump inhibitors and their co-formulated drugs, available as binary combination, by HPTLC on silica gel with toluene – iso-propranol – acetone – ammonia 50:23:25:2. Identification of 14 analytes (except for rabeprazole and lansoprazole which could not be separated) based on hRf and recorded peak spectra. Qantitative determination by densitometry at 290 nm. The linear response for the selected drugs was good with correlation coefficients ≥0.9993. The LOD and LOQ was between 7-160 ng/band and 21-478 ng/band, respectively, for all the analytes. Assessment of the method performance by analyzing different laboratory simulated mixtures and some marketed formulations of the selected drugs, and successful application of the method to investigate potential counterfeit of proton pump inhibitors through a series of simulated formulations with good accuracy and precision.

J. Planar Chromatogr. 31, 265-271 (2018). HPTLC of aspirin (1), paracetamol (2), and caffeine (3) in saliva, after ultrasound-assisted emulsification microextraction, with chloroform on silica gel with ethyl acetate - acetic acid 19:1. Detection under UV light at 254 nm. Quantitative determination using ImageJ software. The hRF values for (1) to (3) were 90, 80 and 50, respectively. Linearity ranged between 4 and 200 μg/zone for (1) to (3). LOD and LOQ were 12 and 38 μg/zone for (1), 8 and 26 μg/zone for (2), and 7 and 23 μg/zone for (3), respectively. The intermediate precision was <10 % (n=3). Recovery was in the range of 89-94 % in saliva for (1) to (3).

J. Chromatogr. 323, 456-461 (1985). HPTLC separation of trimethoprim, sulfamethoxazole on silica with chloroform - ethanol 9:1. Use of sulfanilamide as internal standard. Quantification by densitometry by absorbance at 284 nm. Relative standard deviation of 1.6 % with 30 samples of 200 nl of sulfamethoxazole. Calibration curves linear over the concentration range of 20-160 ng per spot for both substances.

Pharmazie 43, 31-32 (1988). TLC of haloperidol and its degradation products on silica with p-dioxane - benzene - ethanol - NH3 50:40:7:3. Visualization under UV.

Anal. Chim. Acta 201, 357-361 (1987). TLC on silica with methanol - chloroform 60:65. Detection by irradiation at 254 nm. Quantification by second-derivative UV spectrophotometry after elution of the scraped-spots.

J. Planar Chromatogr. 1, 76-78 (1988). Imaging analysis of neostigmine and pyridostigmine bromides by SIMS after TLC separation. Measurement of the ratio of ion intensities for the signal of the intact cation of sample and that of deuteriumlabeled analog at a mass 3 daltons higher.

J. Planar Chromatogr. 2, 153-155, (1989). For doping control, extracts from urine are chromatographed on silica gel with ethyl acetate - methanol - NH3 25% 85:10:5. Post chromatographic derivatization (diazotation/coupling reaction) indicates the presence of oxprenolol. Densitometric quantification of the underivatized chromatogram by absorbance at 270 nm; determination limit, 50 µg/L. Ed.: see CAMAG application A-50.

J. Liquid Chromatogr. 13, 1933-1941 (1990). Reversed-phase TLC on silanized silica with citrate phosphate buffer pH 6.0 - methanol 7:3. Detection under UV. Quantification by densitometry at 302 nm, or by photometry at 302 nm after extraction from the plate with methanol - 0.1 N hydrochloric acid. Comparison of the method with HPLC and PC.