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 %.

J. Planar Chromatogr. 29, 469-473 (2016). HPTLC of miconazole in creams on silica gel with ethyl acetate ‒ 25 % ammonia 50:1. Quantitative determination by absorbance measurement at 228 nm. The hRF value for miconazole was 57. Linearity was between 1250 and 3000 ng/zone. The intermediate precisions were below 2 % (n=6). Recovery ranged between 98.0 and 106.9 %.

J. Planar Chromatogr. 30, 154-163 (2017). HPTLC of chlorpyrifos (1), quinalphos_x000D_ (2), and triazophos (3) on silica gel with n-hexane ‒ acetone 9:1 and on RP-18 with acetonitrile ‒ water 4:1. The results indicated that the hRf values of all three pesticides increased with the polarity of the solvent.

J. Planar Chromatogr. 30, 205-210 (2017). HPTLC of kaempferol (1), scopoletin (2), and vanillic acid (3) in Euphorbia sororia on silica gel with methylbenzene – ethyl acetate – formic acid 80:30:7 for (1) and (2), and methylbenzene – ethyl acetate – methanol – formic acid 35:15:5:3 for (3). Quantitative determination by absorbance measurement at 330 nm for (1) and (2) and 300 nm for (3). The hRF values for (1) to (3) were 47, 33 and 56, respectively. Linearity was between 530-2680 ng/zone for (1), 112-566 ng/zone for (2) and 1083-5381 ng/zone for (3). LOD and LOQ were 17 and 32 ng/zone for (1), 13 and 50 ng/zone for (2) and 10 and 103 ng/zone for (3), respectively. The intermediate precision was below 3 % (n=3). Average recovery rate was 99.3 % for (1), 100.0 % for (2) and 98.1 % for (3).

J. Planar Chromatogr. 30, 291-298 (2017). HPTLC of cefuroxime axetil and cefepime in human whole blood and urine on silica gel with chloroform – ethyl acetate – glacial acetic acid – water 4:4:1:3 for (1) and ethanol – 2-propanol – glacial acetic acid – water 4:4:1:3 for (2). Quantitative determination at UV 285 nm for (1) and 266 nm for (2). The hRF values for (1) and (2) were 89 and 21, respectively. Linearity was between 3-77 μg/mL for (1) and 3-38 μg/mL for (2). The intermediate precision (n=6) was <2 % for (1) and (2). LOD and LOQ were in the range of 40 and 470 ng/zone. Recovery rate ranged from 95.8 to 101.5 % for (1) and (2).