J. Liq. Chromatogr. Relat. Technol. 37, 941-950 (2014). HPTLC of ibuprofen (1) and famotidine (2) on silica gel with methanol - ethyl acetate - hexane - ammonia 4:12:2:1. Quantitative determination by absorbance measurement at 264 nm. The hRf values for (1) and (2) were 41 and 69, respectively. Linearity was in the range of 320-9600 ng/zone for (1) and 10-300 ng/zone for (2). LOD and LOQ were 104 and 316 µg/mL for (1) and 3 and 10 µg/mL for (2). Recoveries (by standard addition) were in the range of 100-101 % for both (1) and (2). Intermediate intra- and inter-day precision was below 2 % (n=3).

J. Sep. Sci. 36, 2703-2708 (2013). HPTLC of biotin in Euphausia superba on silica gel with dichloromethane - 2-propanol - methanol 3:3:2 + 1 drop glacial acetic acid. Detection (1) by spraying with 0.1 - 1 % 4-(dimethylamino)cinnamaldehyde and sulfuric acid in ethanol, followed by drying for 5 min and spraying with liquid paraffin - chloroform 1:10. Alternatively, biotin was detected (2) by spraying with 0.05 % potassium permanganate. Quantitative determination by absorbance measurement at 530 nm for (1) and 400 nm for (2). The hRf value of biotin was 50. Linearity was in the range of 340-3310 ng/zone for both (1) and (2). LOD and LOQ were 50 and 90 ng/zone for (1) and 60 and 100 ng/zone for (2). Average recoveries were 99.6 % for (1) and 99.7 % for (2). Intermediate intra- and inter-day precision was below 2 % (n=3).

J. Planar Chromatogr. 26, 254-259 (2013). HPTLC of ursolic acid (1), betulinic acid (2), beta-sitosterol (3), and lupeol (4) in the stem bark, root bark and leaves of Alstonia scholaris on silica gel with chloroform - methanol 99:1. Detection by dipping into vanillin-sulfuric acid reagent for 2 s, followed by heating at 96 ºC for 8 min. Quantitative determination by absorbance measurement at 680 nm. The hRf values for (1) to (4) were 18, 27, 57 and 77, respectively. Linearity was in the range of 2-10 µg/zone for (1) and 84) and 4-20 µg/zone for (2) and (3). LOD and LOQ were 330 and 1100 ng/zone for (1), 530 and 1310 ng/zone (2), 290 and 970 ng/zone for (3) and 340 and 1140 ng/zone for (4), respectively. Average recoveries (by standard addition) for (1) to (4) were between 98.9 and 100.5 %. Intermediate/interday/intra-day precision was below 2 % (n=9).

J. Planar Chromatogr. 27, 299-314 (2014). 2D-HPTLC of 115 toxicological relevant drugs in serum or blood on silica gel with different solvent mixtures. Quantitative determination by absorbance measurement at different wavelenghts. The 2D-HPTLC method provided significant qualitative and quantitative improvements related to separation efficiency, comparable with HPLC-DAD, GC-MS and LC-MS.

J. Planar Chromatogr. 27, 157-161 (2014). HPTLC of withanoside V (1), withaferine A (2), 1,2-deoxywithastramonolide (3), withanone (4), withanolide A (5), and withanolide B (6) on silica gel with dichloromethane - toluene - methanol - acetone - diethyl ether 13:14:8:3:1. Quantitative determination by absorbance measurement at 235 nm. The hRF values for (1) to (6) were 7, 55, 61, 63, 66 and 77, respectively. Precision was below 2 % (n=3). The LOD and LOQ were 60 and 250 ng/zone for (1), 120 and 350 ng/zone for (2), 80 and 300 ng/zone for (3), (4) and (6), and 60 and 250 ng/zone for (5), respectively. Average recoveries for (1) to (6) were 97, 98, 99, 98, 98 and 99 %, respectively.

J. Planar Chromatogr. 27, 192-198 (2014). HPTLC of losartan (1), irbesartan (2), valsartan (3), and_x000D_ olmesartan (4) in plasma and dosage form on silica gel with chloroform - glacial acetic acid 3:1. Quantitative determination by absorbance measurement at 255 nm. The hRF values for (1) to (4) were 36, 45, 78 and 23, respectively. Linearity was in the range of 90-750 ng/zone for compounds (1) to (4). The intermediate/interday/intra-day precisions were below 3 % (n=6). The LOD and LOQ were 30 and 91 ng/zone for (1), 18 and 56 ng/zone for (2), 15 and 45 ng/zone for (3) and 30 and 92 ng/zone for (4), respectively. Recovery was between 96.4 and 99.5 % for (1) to (4).

J. of China Pharm. 21 (11), 32-34 (2012). Jianxin Jiaonang capsule is a herbal TCM for cardiovascular diseases, such as viral myocarditis, arrhythmia, etc. For quality control, TLC on silica gel 1) for Astragalus membranaceus (Fisch.) Bunge and the standard astragaloside A, with chloroform – methanol – water 13:7:2, detection by spraying with 10 % sulfuric acid in ethanol and heating at 105 °C until the zones are visible in daylight; 2) for Radix Sophorae flavescentis and the standard matrine, with benzene – acetone - ethyl acetate – concentrated ammonia 10:15:20:1, detection by spraying with 5 % potassium iodobismuthate in water – hydrochloric acid 200:1, detection in daylight. TLC of astragaloside A in extracts of the formulation on silica gel with chloroform – methanol – acetone 2:1:2, detection as mentioned. Quantification of astragaloside A by densitometry at 510 nm. The linearity was in the range of 0.54-5.4 μg/zone (r=0.9991, n=6), the stability of the same spot within 2 hours was 2.1 % (%RSD, n=9), precision within plate (%RSD, n=5) was 2.7 %, repeatability (%RSD, n=5) was 3.8 %, and recovery was 97.6 % (%RSD=2.1 %, n=5).

J. Planar Chromatogr. 27, 58-65 (2014). HPTLC of ternary mixtures of cetirizine dihydrochloride (1), pseudoephedrine (2), and/or phenylpropanolamine (3) and paracetamol (4) on silica gel with methanol - water 199:1. Quantitative determination by absorbance measurement at 257 nm. The hRF values for compounds (1) to (4) were 66, 16, 23 and 83, respectively. Linearity was in the range of 1-4 µg/zone for (1), 3-10 µg/zone for (2), 4-8 µg/zone for (3) and 5-100 µg/zone for (4), respectively. The intermediate/interday/intra-day precisions were below 2 % (n=5). The LOD and LOQ were 0.3 and 1 µg/zone for (1), 0.9 and 3 µg/zone for (2), 1.2 and 4 µg/zone for (3) and 1.5 and 5 µg/zone for (4), respectively. Mean recoveries for (1) to (4) were close to 100 %.