J. Planar Chromatogr. 24, 53-56 (2011). HPTLC of the pesticides temephos and fenitrothion on silica gel, prewashed with methanol, with acetone - hexane 3:7 in an unsaturated twin-trough chamber. Quantitative determination by densitometry in absorbance mode at 290 nm. The hRf values were 55 and 69. LOD was 20 ng for temephos and 10 ng for fenitrothion. Recovery was 80-107 % with relative standard deviations of 4.4-20.2 %.

J. Liq. Chromatogr. Relat. Technol. 34, 902-919 (2011). HPTLC of metformin (1) in combination A with glicazide (2) and in combination B with glimepriride (3), in pharmaceutical formulations on silica gel with ammonium sulfate (0.25 %) - methanol - ethyl acetate 4:1:1. Quantitative determination by absorbance measurement at 235 nm (combination A) and 285 nm (combination B). The hRf values for (1) and (2) were 39 and 66, and for (1) and (3) 32 and 69, respectively. Linearity was 5-25 µg/zone for (1) and 0.8-40 µg/zone for (2) in combination A, and 150-250 µg/zone for (1) and 0.3-0.5 µg/zone for (3) in combination B. In A, LOD and LOQ were found to be 61 and 190 ng/zone for (1), and 40 and 150 ng/zone for (2), respectively. In B, LOD and LOQ were 95 and 205 ng/zone for (1) and 30 and 70 ng/zone for (3). Values for repeatability and intermediate precision studies were below 2 %. Recoveries (by standard addition) ranged between 98.9-100.3 %.

J. AOAC Int. 93, 783-786 (2010). HPTLC of etoricoxib (ETO) and thiocolchicoside (THIO) on silica gel (prewashed with methanol) with ethyl acetate - methanol 4:1 in a twin-trough chamber after preconditioning for 20 min. Quantitative determination by absorbance measurement at 290 nm. The calibration curve was linear over a range of 50-250 and 100-500 ng/band with correlation coefficients of 0.9948 and 0.9958 for ETO and THIO, respectively. LOD and LOQ were 11 and 33 ng/band for ETO and 25 and 76 ng/band for THIO. %RSD values were found to be 0.5 and 0.8 % for ETO and THIO for intra-day variations, while inter-day variations were 1.2 and 1.0 %, respectively. The recovery for ETO was between 100.2-101.1 % and for THIO 98.7-100.4 %.

J. of China Three Gorges Univ. Natural Sciences 33 (4), 92-95 (2011). TLC of extracts of Biyuan Pills on silica gel 1) for Magnolia liliiflora Desr. with dichloromethane - ethyl acetate 9:1, detection by spraying with 10 % sulfuric acid in ethanol and heating at 90 °C until the zones were detected; 2) for Xanthium sibiricum Patr., with chloroform - ethyl acetate - methanol - water - formic acid 3:10:2:2:2, detection by exposure to iodine vapor until the zones were detected; 3) for Lonicera japonica and Chrysanthemum indici flos, with toluene - ethyl acetate - formic acid - glacial acetic acid - water 1:15:1:1:2, detection under UV 365 nm.

J. Trad. Chinese Med. & Pharm. Consult. 3 (7), 368-369 (2011). Hormones have been widely applied in clinical practice, however, overdose hormones are liable to cause general anaphylaxis, and even serious harm to physical health. For quick identification of hormones in traditional Chinese preparations, TLC of the extracts of the preparations on silica gel with chloroform – petroleum ether (30-60 ºC) – methanol 5:3:1, detection at UV 254 nm. Identification of methyltestosterone, prednisolone acetate, estrone, ethinyloestradiol, prednisolone acetate, testosterone undecanoate, fluocinolone acetonide, dexamethasone, betamethasone sodium phosphate, and hydrocortisone acetate by fingerprint comparison with the standards. The method has been applied to the real life samples of four varieties of preparation. The results were compatible with those obtained by HPLC and MS-MS.

J. of China Pharm. 21 (20), 34-35 (2012). Zhongtongxiao capsules are a herbal TCM preparation to treat blood stasis and sore swellings caused by fracture. TLC of the extracts of the medicine on silica gel 1) for Angelica sinensis and the rhizome of Chuanxiong, with n-hexane – ethyl acetate 9:1, detection at UV 366 nm; 2) for Radix Paeoniae, with chloroform – ethyl acetate – methanol – formic acid 200:25:50:1, detection by spraying with 5 % vanillin in ethanol – sulfuric acid 200:1 and heating at 105 °C until the zones are visible, viewing in daylight; 3) for Teasel, developed with toluene – ethanol 9:2, detection by spraying firstly with potassium iodobismuthate – hydrochloric acid – water 10:1:200 and then with 5 % nitrous acid in ethanol, followed by viewing in daylight; 4) for Licorice, with the lower phase of 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, viewing in daylight.

Chinese J. of Veterinary Drugs 46 (5), 29-31 (2012). TCM is more and more important in veterinary medicine. It has been found that some medicines were illegally mixed with certain chemicals harmful to the animal body. Rapid screening of the additives illegally mixed in Astragalus polysaccharides injection by TLC on silica gel with 1) chloroform – methanol – acetone – ammonia 9:2:1:0.05 and 2) ethyl acetate – ethanol 1:1. Detection 1) under UV 254 nm; 2) by spraying with 5 % potassium iodobismuthate solution and evaluation in daylight; 3) by exposure to iodine vapor for a few minutes and evaluation under UV 254 nm. Identification of lincomycin, enrofloxacin, novalgin, 4-acetamino phenol, moroxydine hydrochloride, and ribavirin by comparison of the fingerprint with individual standards, with detection limits of 2.0, 0.5, 1.0, 0.5, 1.0, and 4.0 mg/mL, respectively. The method was applied to 25 batches of market samples and the results were compatible with those obtained by HPLC.

J. Liq. Chromatogr. Relat. Technol. 35, 2753-2764 (2012). HPTLC of melitracen hydrochloride (1) and flupentixol hydrochloride (2) on silica gel with methanol - chloroform - toluene 2:9:9 + 1 drop ammonia. Quantitative determination by absorbance measurement at 291 nm. The hRf value of compounds (1) and (2) were 53 and 34 and selectivity regarding matrix was given. Linearity was in the range of 1600-6400 ng/band and 80-320 ng/band for (1) and (2), respectively. Limit of detection was found to be 27 ng/band and 5 ng/band for (1) and (2), respectively. Limit of quantification was found to be 82 ng/band and 14 ng/band for (1) and (2), respectively. The intermediate/inter-day/intra-day precision was below 0.2 % for (1) and 1.1 % for (2) (n=3). Recovery (by standard addition) was between 99.1 and 101.8 % for both (1) and (2). The method showed comparable results with HPLC.