Nature - Lab. Invest. 100, 1411–1424 (2020). Samples were chloroform – methanol 1:1 solutions of lipid standards and of liver tissue extracts from wild-type mice (1), from transgenic murine models of hepatic steatosis (2) (mice expressing HBs, hepatitis B virus surface protein), or of cholestasis (3) (mice totally knock-out for the gene of phospholipid translocator ABCB4, ATP-binding cassette subfamily B member 4), or of both (4) (hybrids of mice (2) and (3)). HPTLC on silica gel (preheated at 110°C for 15 min) with n-hexane – diethyl ether – acetic acid 20:5:1. (A) For qualitative analysis, visualization under white light after immersion into anisaldehyde 0.5 % (in sulfuric acid – acetic acid – methanol, 1:2:17), followed by heating at 110°C for 9 min. (B) Identification of lipids was confirmed by elution of the zones of interest with methanol from the HPTLC layer through a TLC-MS interface and a filter frit directly to a quadrupole-orbitrap MS (atmospheric pressure chemical ionization, full HR-MS scan in m/z range 100–1000). (C) For quantitative analysis, visualization at UV 366 nm after derivatization by immersion into primuline reagent (primuline 0.5 g/L in acetone – water 4:1); fluorescence was measured at UV 366 nm (mercury lamp, optical filter for wavelengths above 400 nm, scanning slit 6.0 mm × 0.2 mm, speed 20 mm/s). (A) and (B) allowed the separation and detection of cholesterol, cholesteryl oleate, methyl oleate, free fatty acids (FFA, expressed as oleic acid equivalents) and triacylglycerols (TAG, as triolein equivalents) in liver extracts. (C) showed that TAG was decreased and FFA increased in (3) and (4), compared to (1) and (2). Cholesterol and cholesteryl oleate had no significant changes between groups.

Nature - Sci. Rep. 11, 62 (2021). Samples were isopropylacetate – methanol 3:2 fractions of (1) n-hexane extracts of larvae of Apis mellifica carnica (Apidae) from hives exposed to different concentrations of neonicotinoid pesticide clothianidin in their food, as well as (2) worker jelly adsorbed from brood combs of the same hives on adsorptive filter strips (unused filter strip parts were kept as background control). HPTLC on silica gel with chloroform – methanol – water – ammonia 30:17:2:1 for (1), and with an 8-step gradient based on methanol, chloroform, toluene, and n-hexane for (2, see CBS 105: Optimization of an AMD 2 method for determination of stratum corneum lipids). Visualization at UV 366 nm before and after derivatization by immersion into primuline reagent (primuline 0.5 g/L in acetone – water 4:1). Furthermore, antibacterial activity of (2) was assessed by recording the bioluminescence on the HPTLC plates, neutralized after elution and immersed into Aliivibrio fischeri suspension. Semi-quantitative comparison showed that a higher exposure to clothianidin was correlated with a decrease in lipid composition as well as in antibacterial activity.

J. Planar Chromatogr. 34, 447-453 (2021). HPTLC of gallic acid (1) and ellagic acid (2) in Triphala on silica gel with toluene - ethyl acetate - formic acid - methanol 15:15:5:1. Quantitative determination by absorbance measurement at 254 nm. The hRF values for (1) and (2) were 35 and 28, respectively. Linearity was between 200 and 2000 ng/zone for (1) and 50 and 400 ng/zone for (2). LOD and LOQ were 200 and 606 ng/zone for (1) and 50 and 151 ng/zone for (2), respectively. Intermediate precisions were below 2 % (n=3). Average recovery was 98.6 % for (1) and 99.1 % for (2).

J. Planar Chromatogr. 34, 455-466 (2021). HPTLC of mometasone furoate (1) and salicylic acid (2) on silica gel with chloroform - ethanol 9:1. Quantitative determination by absorbance measurement at 250 nm for (1) and 300 nm for (2). The hRF values for (1) and (2) were 13 and 93, respectively. Linearity was between 100 and 1600 ng/zone for (1) and 400 and 5000 ng/zone for (2). LOD and LOQ were 16 and 47 ng/zone for (1) and 7 and 20 ng/zone for (2), respectively. Intermediate precisions were below 2 %. Recovery was between 98 and 102 %.

J. Planar Chromatogr. 34, 411-418 (2021). HPTLC of sphingomyelin in erythrocyte membranes of patients on silica gel with chloroform - methanol - acetic acid - water 60:50:1:4. Detection by exposure to iodine vapor for 30 min. Quantitative determination by densitometric measurement of the intensity of individual zones and the red, green and blue values of the component colors. The hRF value for sphingomyelin was 86. Linearity was between 0.25 and 10 μg/zone. LOD and LOQ were 140 and 410 ng/zone, respectively. Intermediate precisions were below 2 % (n=3). Recovery was between 85 and 97 %.

J. Planar Chromatogr. 34, 427-435 (2021). HPTLC of phyllanthin (1) and hypophyllanthin (2) in Phyllanthus amarus on silica gel with toluene - ethyl acetate 17:3. Quantitative determination by absorbance measurement at 254 nm. The hRF values for (1) and (2) were 21 and 35, respectively. Linearity was between 2 ans 7 μg/zone for (1) and (2). LOD and LOQ were 1 and 3 μg/zone for (1) and (2), respectively. Intermediate precisions were below 2 % (n=3).

J. Planar Chromatogr. 34, 419-426 (2021). HPTLC of brazilin on silica gel with chloroform - acetone - formic acid 8:4:1. Detection by exposure to ammonia vapor, followed by spraying with aluminum chloride. Quantitative determination by absorbance measurement at 508 nm. Linearity was between 0 to 6 μg. Intermediate precisions were below 3 %. Recovery was between 100 and 105 %.

J. Planar Chromatogr. 34, 467-477 (2021). HPTLC of five antihypertensive drugs, atenolol (1), amlodipine (2), losartan (3), hydrochlorothiazide (4), and telmisartan (5) on silica gel with chloroform - toluene - methanol - acetone - formic acid 400:300:150:260:3. Quantitative determination by absorbance measurement at 254 nm. The hRF values for (1) to (5) were 7, 12, 45, 56 and 64, respectively. Linearity ranged from 1-25 μg/zone for (1), (3) and (5) and 1-20 μg/zone for (2) and (4). LOD and LOQ were 300 and 900 ng/zone for (1), 130 and 420 ng/zone for (2), 230 and 690 ng/zone for (3), 140 and 430 ng/zone for (4) and 190 and 560 ng/zone for (5). Intermediate precisions were below 1 % (n=9). Mean recovery was 99.3 % fo (1), 100.1 % for (2), 99.7 % for (3), 99.7 % for (4) and 100.3 % for (5).