J. Liq. Chromatogr. Relat. Technol. 37, 2784-2799 (2014). HPTLC of atorvastatin (1), ezetimibe (2) and fenofibrate (3) on silica gel with toluene – methanol – triethylamine 16:3:1. Quantitative determination by absorbance measurement at 245 nm. The hRF values for (1) to (3) were 10, 20 and 80, respectively. Linearity was in the range of 100-350 ng/zone for (1) and (2) and 1600-5600 ng/zone for (3). The intermediate/interday/intra-day precisions were below 1 % (n=3). The LOD and LOQ were 60 and 90 ng/zone for (1), 80 and 100 ng/zone for (2) and 90 and 150 ng/zone for (3), respectively. Recoveries were in the range of 97.6-102.6 %.

by high-performance thin-layer chromatography) (Chinese). J. Chinese Trad. Patent Med. 35 (12), 2752-2754 (2013). Chimonanthus nitens Oliv. is a plant of the Calycanthaceae family growing in Jiangxi and Anhui areas of China. Pharmacological studies showed that the chemical constituents of the extracts of its dry leaves are volatile oils, alkaloids, flavonoids, coumarins, etc. The dry leaves are used clinically as the main ingredient drug in TCM prescriptions for the treatment of infantile cough, respiratory tract infection, hand foot and mouth disease and chronic pelvic inflammatory disease, etc. For quality control, HPTLC of the sample extracts and the standards cineole, linalool and beta-caryophyllene on silica gel firstly with chloroform – methanol 9:1 to 5 cm and then with petroleum ether (30-60 °C) – ethyl acetate 10:1 to 10 cm, detection by spraying with 1 % vanillin in sulfuric acid – ethanol 1:4 and heating at 110 °C. Quantitative determination by densitometric evaluation at 606 nm for cineole and linalool and 545 nm for beta-caryophyllene using external standard calibration method. The content of the total unknown components is also given taking linalool as the calibration standard. Validation of the method by investigation of its linearity range (for cineole 0.7-11.4 µg/zone, r=0.990, n=7; for beta-caryophyllene 0.7-10.9 µg/zone, r=0.992, n=7; for linalool 1.8-18.0 µg/zone, r=0.990, n=7), precision (%RSD (n=6) 3.9 %, 1.5 % and 0.6 % for cineole, beta-caryophyllene and linalool, respectively), stability (within 30 min, %RSD (n=6) 2.0 %, 3.0 % and 3.3 % for cineole, beta-caryophyllene and linalool, respectively) and reproducibility (%RSD (n=6) 2.7 %, 4.4 % and 3.2 % for cineole, beta-caryophyllene and linalool, respectively). The recovery for cineole was 82.3-93.4 % (%RSD (n=3) 2.6-4.1 %), for beta-caryophyllene 86.1-96.7 % (%RSD (n=3) 2.2-3.6 %) and for linalool 95.8-109.8 % (%RSD (n=3) 1.9-2.9 %). Some unknown separated components need to be identified in a further study.

Innov. Food Sci. Emerg. Technol. 26, 490-497 (2014). HPTLC of the isoflavones (1) glycitin, (2) daidzin and (3) genistin in fermented soybean powder on silica gel with toluene - ethyl acetate - formic acid - acetic acid 2:16:2:1. Quantitative determination by absorbance measurement at 260 nm. The hRF values of (1) to (3) were 36, 44 and 58, respectively.

J. Planar Chromatogr. 27, 438-443 (2014). HPTLC of (1) alpha-amyrin, (2) lupeol, and (3) beta-sitosterol in the leaves of Kalanchoe pinnata, Bombax ceiba, and Morus alba on silica gel with toluene – ethyl acetate 19:1. Detection by dipping into anisaldehyde–sulphuric acid reagent for 1 min, followed by heating at 100 °C for 5 min. Quantitative determination by absorbance measurement at 525 nm. The hRF values of (1) to (3) were 71, 28 and 16 respectively. Linearities were in the range of 160-560 ng/zone for (1), 150-900 ng/zone for (2) and 80-480 ng/zone for (3). The intermediate precision was below 2 % (n=3) for (1) to (3). The LOD and LOQ were 60 and 160 ng/zone for (1), 50 and 150 ng/zone for (2) and 20 and 48 ng/zone for (3), respectively. Average recoveries for (1) to (3) were 100.7, 99.8 and 100.1 %, respectively.

Chinese J. Sci. & Technol. Review 17, 220-221 (2013). Zhihe Piba Keli pill is a TCM compound for the treatment of cough. For quality control, microemulsion TLC of Stemona sessilifolia (Miq.) Miq., Morus alba L. and Cynanchum glaucescens (Decne.) Hand.-Mazz on polyamide thin-films with (SDS - n-butanol – n-heptane 2.7:6.3:1.0) – formic acid 9:1, detection at UV 366 nm. Demonstration by applying to real life samples indicated that the procedure was suited for quality control.

J. Planar Chromatogr. 27, 346-356 (2014). HPTLC fingerprint of the leaves of Arctium lappa and Fagus sylvatica, herba of Epilobium hirsutum, Lythrum salicaria, and Artemisia dracunculoides; and fruits of Cydonia oblonga and leaves of Hippophae rhamnoides and Aronia melanocarpa on silica gel with ethyl acetate – acetic acid – formic acid – water 50:6:6:13 for flavonoid glycosides and chloroform – acetic acid – methanol – water 16:8:3:2 for saponins. Detection by immersion into natural product reagent followed by PEG 400 reagent. Qualitative identification at UV 366 nm.

J. Liq. Chromatogr. Relat. Technol. 38, 1113-1120 (2015). HPTLC of orbifloxacin (1), danofloxacin (2), ciprofloxacin (3), norfloxacin (4), enrofloxacin (5), marbofloxacin (6), difloxacin (7) and ofloxacin (8) on silica gel with 1,4-dioxane - ammonia - tetrahydrofuran 6:3:2. Quantitative determination by absorbance measurement at 320 nm. The hRF value was 19 for (4), 23 for (3), 30 for (2), 37 for (8), 40 for (6), 44 for (5), 56 for (1) and 59 for (7). Linearity was in the range of 159-513 ng/zone for (1), 99-238 ng/zone for (2), 97-244 ng/zone for (3), 69-163 ng/zone for (4), 63-170 ng/zone for (5), 103-250 ng/zone for (6), 84-251 ng/zone for (7) and 94-260 ng/zone for (8). LOD and LOQ were 53 and 159 ng/zone for (1), 32 and 98 ng/zone for (2), 32 and 97 ng/zone for (3), 23 and 69 ng/zone for (4), 21 and 63 ng/zone for (5), 34 and 103 ng/zone for (6), 28 and 84 ng/zone for (7) and 31 and 94 ng/zone for (8), respectively. Selection of appropriate viscosity of the mobile phase may be important in obtaining optimal chromatographic separation.

J. Planar Chromatogr. 28, 287-293 (2015). HPTLC of bacoside A in the leaves of Bacopa monnieri on silica gel with ethyl acetate - methanol - water 4:1:1. Detection by spraying with 1 % vanillin in 10 % methanolic sulfuric acid. Quantitative determination by absorbance measurement at 598 nm. The hRF value for bacoside A was 53. LOD and LOQ were 60 and 180 ng/zone, respectively. The intermediate precision was below 1 % (n=3). Recovery ranged between 97 and 100 %.