J. Planar Chromatogr. 36, 433-438 (2023). HPTLC of synthetic cannabinoids AM2201 (1), CP-47,497 (2), and JWH-018 (3) in seized samples on silica gel with cyclohexane - diethylamine 9:1. Quantitative determination by absorbance measurement at 280 nm for (2) and 315 nm for (1) and (3). The hRF values for (1) to (3) were 26, 73 and 55, respectively. Linearity was between 2 and 14 µg/zone for (3), 5 and 35 µg/zone for (1) and 50 and 350 µg/zone for (2). The intermediate precision was 23.0 % for (1), 16.6 % for (2) and 7.5 % for (3). The LOD and LOQ were 5.6 and 16.9 µg/zone for (1), 0.7 and 2.2 µg/zone for (2) and 1.9 and 5.6 µg/zone for (3). Average recovery was 84.0 % for (1), 105.1 % for (2) and 107.1 % for (3).

Pharmacogn. Mag. DOI: 10.1177/09731296231189619 (2023). HPTLC of naringenin (1), ferulic acid (2) and caffeic acid (3) in Nyctanthes arbor-tristris on silica gel with toluene - ethyl acetate - formic acid 6:4:1. Quantitative determination by absorbance measurement at 371 nm. Linearity was in the range of 100-4000 ng/zone. Intermediate precisions were below 3 % (n=3). The LOD and LOQ were 30 and 45 ng/zone for (1), 15 and 90 ng/zone for (2) and 17 and 52 ng/zone for (3), respectively. Recovery was in the range of 86.7-96.3 % for (1), 101.6-102.7 % for (2) and 100.8-101.8 % for (3).

Chinese J. Ethnomed. & Ethnopharm. 32 (22), 42-46 (2023). Sophora alopecuroides is a medicinal plant growing in Northern China, containing alkaloids, flavonoids, volatile oils and amino acids. It has antipyretic detoxification, antibacterial and anti-inflammatory, as well as analgesic effects, and is the main effective ingredient in some TCM mixtures widely used in clinical practice. This research team developed a medicinal gel, Kudouzi Ningjiaoji gel, which has good clinical results in the treatment of acne, pustules and other diseases. For quality control, TLC of the extracts of Kudouzi Ningjiaoji gel on silica gel with dichloromethane – methanol – ammonia water 50:6:1. Detection in daylight after spraying with a solution of bismuth potassium basic nitrate 0.85 g, glacial acetic acid 10 mL, water 40 mL and potassium iodide 2 g. Identification by comparing of sample fingerprints with those standards sophoridine and matrine.

J. Ethnopharmacol. 321, 117566 (2024). HPTLC of Evolvulus alsinoides on silica gel with toluene - ethyl acetate - formic acid 6:3:1. Qualitative identification under UV light between 450 and 550 nm. The hRF values of methanol extract ranged from 3 to 64. 

J. Chinese Pharm. 34 (1), 52-56 (2023). Inonotus obliquus is a new source of fungal medicine, containing polysaccharides, polyphenols, triterpenoids, sterols and folic acid derivatives, with various pharmacological effects such as anti-tumor, hypoglycemic, antioxidant, and antiviral. For identification, TLC of its extracts on silica gel, A) for thrombotic acid, with chloroform – toluene – ethyl acetate – methanol 10:4:1:1; and B) for inotodiol, with dichloromethane – toluene – ethyl acetate – methanol 100:40:3:3. Detection for both by spraying with 5 % phosphomolybdate in ethanol and heating at 105°C until the zones are visible in daylight. Identification by fingerprint comparison with the standard drug Inonotus obliquus and the standards thrombotic acid and inotodiol. Chemical pattern recognition analysis was applied on resulting TLC and HPLC data (such as, cluster analysis, principal component analysis, orthozonal least squares-discriminant analysis) to evaluate the quality of the medicine.

Phytochem. Anal. 35, 163-183 (2024). HPTLC of Cannabis sativa on silica gel with n-heptane - methyl tert-butyl ether - ethanol - formic acid 780:170:50:3. Detection by spraying with vanillin-sulfuric acid (VSA) reagent (5 % methanolic solutions), followed by heating at 120 °C for 3 min. Fast Blue solution (0.5 % in water - methanol - dichloromethane 2:5:3) was used for derivatisation as a selective stain for cannabinoids. A 0.1 M sodium hydroxide solution in methanol - water 9:1 was used to improve color development.

Food Addit. Contam. Part A. 40, 1495-1530 (2023). Review of common screening techniques for the detection of 112 unapproved phosphodiesterase type 5 inhibitors found as adulterants in sexual enhancement dietary supplements, including HPTLC. Combination of HPTLC with other non-chromatographic techniques were also described.

Trends Anal. Chem. 167, 117276 (2023). Review of extraction and chromatographic methods to evaluate active forms of fat-soluble vitamins in various matrices, including HPTLC for the analysis of vitamins K, D, carotenoids in pharmaceutical products, dietary supplements and complex matrices.