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.

J. Planar Chromatogr. 28, 42-47 (2015). HPTLC of (1) homoeriodictyol and (2) persicogenin in the methanol extract of the aerial parts of Rhus retinorrhoea and Rhus tripartita on silica gel with toluene - ethyl acetate - methanol 16:4:1. Quantitative determination by absorbance measurement at 293 nm. The hRF values of (1) and (2) were 30 and 48. Linearity was between 100 and 800 ng/zone for both, (1) and (2). The intermediate intra-day and inter-day precisions were below 2 % (n=6). The LOD and LOQ were 26 and 77 ng/zone for (1) and 31 and 92 ng/zone for (2), respectively. Recoveries were in the range of 98.9-99.5 % for (1) and 98.3-99.2 % for (2).

J. Planar Chromatogr. 27, 398-402 (2014). HPTLC of (1) permethrin and (2) fenpropathrin in water samples on silica gel with petroleum ether (60-90 °C) - ethyl acetate - dichloromethane 192:5:3. Detection by spraying with 10 mL of phosphomolybdic acid solution (7%, w/v, in ethanol), followed by heating at 170 °C for 10 min. The hRF values of (1) and (2) were 52 and 34, respectively. Linearity was in the range of 8.7-30.6 ng/mL for (1) and 5.4-19.1 ng/mL for (2). The intermediate precision was below 2 % (n=5) . The LOD and LOQ were 0.44 and 1.47 ng/mL for (1) and 0.56 and 1.88 ng/mL for (2), respectively. Average recoveries for (1) and (2) were 92.5 and 95.6 %, respectively.

J. Planar Chromatogr. 27, 416-419 (2014). HPTLC of (1) cotinine and (2) trans-3'-hydroxycotinine in urine on RP-18 with acetonitrile - water 4:1. Quantitative determination by absorbance measurement at 260 nm. Linearity was in the range of 65-325 ng/zone (at a low calibration range) and 325-1300 ng/zone (at a high calibration range) for (1) and 62.5-312.5 and 312.5-1250 ng/zone for (2). The intermediate precisions were below 9 % (n=3). The LOD and LOQ were 13 and 38 ng/zone for (1) and 17 and 50 ng/zone for (2), respectively.

J. Sep. Sci. 38, 592-598 (2015). HPTLC of erythrocentaurin on silica gel with toluene - ethyl acetate - formic acid 40:9:1. Quantitative determination by absorbance measurement at 230 nm. The hRF value of erythrocentaurin was 54. Linearity was in the range of 200-1500 ng/zone. LOD and LOQ were 60 and 180 ng/zone, respectively. Intra-day and inter-day precision was below 1 % (n=3). Recoveries were between 97 and 99 %.

J. Chromatogr. A 1390, 103-111 (2015). HPTLC-Vis-ESI-MS of 6 dyes in a commercially available dye mixture on silica gel with toluene up to a migration distance of 60 mm. Detection under white light and absorbance measurement using a multi-wavelength scan at 450, 500, 530 and 620 nm. Via the TLC-MS Interface the dye zones were eluted with methanol - ammonia formiate buffer (10 mM, pH 4.8) 19:1 at a flow rate of 0.1 mL/min into a single quadrupole mass spectrometer. Electrospray ionization mass spectra were recorded in full scan mode. Characteristic m/z values of dyes were used for quantitative measurements in SIM mode. The mean precisions (n=5) were below 10 % and a mean correlation was of 0.9975 for the 6 dyes. HPTLC-MS analysis revealed the incorrect assigment of components in two commercially available dye mixtures. Photooxidation degradation products were observed for interrupted workflows (for elutions after several days when the plate was kept in daylight).

J. Planar Chromatogr. 28, 402-406 (2015). Design of low-cost and relatively simple TLC-HPLC-MS set-up for sample elution from TLC plate to the HPLC or MS system. A prototype eluting device with a tubing for direct solute zone collection was constructed. The tubing consisted of a stainless steel capillary into which a Teflon capillary was placed. At the lower bottom of the stainless steel capillary the tip of the Teflon capillary formed a 3 mm deep dimple and the capillary walls were sharpened. The stainless steel capillary was disconnected from the prototype and by pressing the sharpened end on blotting paper a disc was resected which was located directly on the Teflon tip. Then the capillary was pressed against the adsorbent layer with the analyte zone. An advantage of the prototype was that this yould be done directly under the UV lamp without the need to mark the analyte zones on the layer. Like this a chip with the adsorbent layer was introduced into the capillary dimple. Then, the chip was covered with another disc of blotting paper (cut using the sharpened capillary). Subsequently, the stainless steel capillary was connected with the prototype, the injection valve was switched and the eluent flow was directed through the stainless steel capillary to the UV–VIS or MS detector. After the elution, the injection valve was switched again, the capillary was disassembled from the prototype and the remnant of the adsorbent layer was removed so that the capillary was ready for the next elution. The results obtained using the prototype device were compared to those obtained with the commercial TLC-MS Interface manufactured by CAMAG. Regardless of the device used the peak areas of the eluted analytes were correlated to their concentrations. However, the average peak area obtained with the TLC-MS Interface was considerably higher than that obtained with the prototype because the diameter of the tip of the stainless steel capillary was only 1 mm compared to the oval elution head (2x4 mm) of the TLC-MS Interface.

Food Res. Int. 76, 142-149 (2015). HPTLC of saponins in chickpea, soy and faba beans on silica gel with chloroform - acetic acid - methanol - water 16:8:3:2. Detection by dipping into p-anisaldehyde sulfuric acid reagent for 2 s, drying for 10 min, followed by heating at 70 °C for 5 min. Quantitative determination by absorbance measurement at 545 nm. The hRF values of saponins were 44-46 as orange band and 48-50 as violet-blue band on a dark background. Saponin identification by hyphenation of HPTLC with mass spectrometry (MS) via a TLC–MS interface.