J. Liq. Chromatogr. Relat. Technol. 38, 1061-1067 (2015). HPTLC of ethambutol (1), isoniazid (2), pyrazinamide (3) and rifampicin (4) on silica gel with acetonitrile - chloroform - 2-propanol - 4N ammonia 34:31:34:1. Quantitative determination by absorbance measurement at 270 nm for (2) to (4) and 250 nm for (1) after a derivatization reaction. The hRF values for (1) to (4) were 9, 31, 48 and 73, respectively. Linearity was in the range of 300-1800 ng/zone for (1), 75-450 ng/zone for (2), 300-1200 ng/zone for (3) and 150-900 ng/zone for (4). LOD and LOQ were 94 and 286 ng/zone for (1), 20 and 62 ng/zone for (2), 18 and 55 ng/zone for (3) and 40 and 121 ng/zone for (4), respectively. The intermediate precision was below 2.5 % (n=6). Recoveries ranged between 97 and 101 %.

Innov. Food Sci. Emerg. Technol. 32, 127-135 (2015). HPTLC of prebiotic oligosaccharides produced in the orange juice on silica gel with acetonitrile - ethyl acetate - 1-propanol - water 17:4:10:18. Detection by spraying with 0.3 % 1-naphthyl ethylenediamine dihydrochloride in methanol with sulfuric acid 3 %, followed by heating at 120 °C for 10 min. The method was applied to determine the degree of polymerization. _x000D_

J. Planar Chromatogr. 28, 362-372 (2015). HPTLC of niacin (1), atorvastatin (2), bezafibrate (3) and ezetimibe (4) or simvastatin (5) in plasma on silica gel with benzene - acetonitrile - n-butanol 7:2:1 + 1.5 % glacial acetic acid. Quantitative determination by absorbance measurement at 242 nm. The hRF values for (1) to (5) were 17, 38, 51, 65 and 66, respectively. Linearity was in the range of 15-650 ng/zone. LOD and LOQ were in the range of 5-50 and 15-150 ng/zone, respectively. The intermediate precision was below 5 % (n=3). Recovery ranged from 95 to 104 %.

J. Planar Chromatogr. 29, 310-317 (2016). HPTLC fingerprinting of two types of German propolis on silica gel with n-hexane – ethyl acetate – glacial acetic acid 5:3:1 under acidic preconditioning. Detection and documentation under UV 366 nm. Image analysis by converting chromatogram images to numerical data sets to form a data matrix. The best preprocessing was obtained by a combination of the median filter, correlation optimized warping, standard normal variate, and mean centering/autoscaling procedure.

Food Chem. 210, 613-622 (2016). HPTLC fingerprinting of triterpenoids in Siam and Sumatra benzoin balsams on silica gel with n-hexane – methanol – acetic acid 8:2:1. Detection by dipping into anisaldehyde sulfuric acid reagent for 1 s (10 mL of sulfuric acid were carefully added to an ice-cold solution of 170 mL methanol and 20 mL acetic acid, followed by the addition of 1 mL of anisaldehyde (p-methoxybenzaldehyde)), followed by heating at 105 °C for 5 min. Qualitative identification under UV 366 nm. Two specific compounds at approximately hRF 5 (violet band) and 50 (beige band) were detected in the Sumatra sample. Siam benzoin is characterized by two specific compounds at approximately hRF 5 and 10 (brown bands) and two others at approximately hRF 20 and 60 (orange bands).

J. of Chromatogr. Sci. 52 (1), 5-11 (2014). Presentation of a method for the simultaneous determination of diacerein in the presence of rhein, the active metabolite and hydrolytic degradation product of diacerein, and emodin, the diacerein impurity, in bulk powder and different pharmaceutical formulations. TLC on silica gel with hexane – ethyl acetate – acetic acid 75:50:1, detection and quantification by densitometry at 230 nm. The hRf values were 12, 44 and 60 for diacerein, rhein and emodin, respectively. The linearity ranges were 0.5–10 µg/band for diacerein and rhein, and 0.5–7 µg/band for emodin. Comparison with a HPLC method showed no significant differences.

J. Planar Chromatogr. 29, 176-183 (2016). HPTLC of atracurium besylate (1) and atropine sulfate (2) on silica gel with acetonitrile – methanol – dichloromethane – glacial acetic acid – water containing 70 mg L-(+)-tartaric acid 70:10:5:7:1, pH 5 for (1), and methanol – water containing 40 mg L-histidine and 20 mg copper(II) acetate 22:3, pH 7 for (2). Quantitative determination by absorbance measurement at 280 nm for (1) and 215 nm for (2). The hRF values for (1) and (2) were 51 and 65, respectively. Linearity was in the range of 2-14 μg/zone for (1) and 5-35 μg/zone for (2). Intermediate precisions were below 1 %. The LOD and LOQ were 0.5 and 1.6 µg/zone for (1) and 1.2 and 3.6 µg/zone for (2). Average recovery was found to be 103.4 % for (1) and 96.6 % for (2).

J. Planar Chromatogr. 29, 341-346 (2016). HPTLC of artemisinin in the seeds of Artemisia annua on silica gel with n-hexane ‒ ethyl acetate ‒ acetic acid 20:10:1. Detection by dipping into anisaldehyde reagent (glacial acetic acid ‒ sulfuric acid ‒ anisaldehyde 50:1:0.5) followed by heating at 110 °C for 5 min. Quantitative determination by absorbance measurement at 540 nm. The hRF value for artemisinin was 43. Linearity was between 200 and 1000 ng/zone. The intermediate precision was below 0.7 % (n=3). The LOD and LOQ were 30 and 80 ng/zone, respectively. Recovery ranged from 82.9 to 87.1 %.