J. Liq. Chromatogr. Relat. Technol. 38, 1499-1506 (2015). RP-HPTLC of piperazine in pharmaceutical formulations on RP-18 with acetonitrile - water 3:2 modified with 1.5 % tetrafluoroborate. Quantitative determination by absorbance measurement at 247 nm. The hRF value for piperazine was 43. Linearity was in the range of 0.8-2.2 μg/zone. LOD and LOQ were 0.11 and 0.34 μg/zone. The intermediate precision was below 3.5 % (n=3). Recovery was between 99 and 103 %. Significant changes and improvements regarding the hRF value were observed when tetrafluoroborate was added to the mobile phase.

Trends Anal. Chem. 81, 51-62 (2016). Review on aspects to consider during calibration for quantitative chromatographic analysis such as noise and detector response, data acquisition and processing, calibration curve and inverse calibration.

J. Planar Chromatogr. 29, 30-37 (2016). HPTLC and pressurized planar electrochromatography (PPEC) of 20 amino acids on silica gel with acetonitrile – buffer pH 3.2 (citric acid – disodium hydrogen phosphate 2.28:1.44) 1:1 for HPTLC and acetonitrile – buffer pH 3.2 4:1 for PPEC. PPEC separation was performed at a polarization voltage of 1.0 kV for 25 min. Detection by spraying with ninhydrin solution, followed by heating in a warm air stream.

J. Liq. Chromatogr. Relat. Technol. 39, 308-311 (2016). HPTLC of trans-resveratrol in Physalis peruviana on silica gel with ethyl acetate – cyclohexane – n-butanol 9:9:2. Chemiluminescence was induced by dipping for 1 s into bis(2,4,6-trichlorophenyl)oxalate (TCPO) solution (50 mg TCPO in 36 mL n-butyl acetate, vigorously shaken for 20 min with 0.4 mL 35 % hydrogen peroxyde). After dipping, the_x000D_
wet plate was dried until no light reflection could be seen on the surface. The hRF value for trans-resveratrol was 78. The LOQ was 20 ng/zone.

J. Planar Chromatogr. 29, 99-107 (2016). Review of the application of TLC for the analysis of neutral and polar lipids found in parasite-infected and noninfected snails. Different aspects of the TLC procedure such as sample preparation, sample and standard application, layers and mobile phases, detection and quantification were reviewed. Compared to earlier reviews, the authors included lipophilic pigments as well as valuable information on numerous species of gastropod molluscs.

J. Planar Chromatogr. 29, 209-215 (2016). HPTLC of berberine in Tinospora cordifolia on silica gel with methanol – acetic acid – water 8:1:1. Quantitative determination by absorbance measurement at 366 nm. The hRF value of ranolazine was 71. Linearity was in the range of 120-360 ng/zone. Intermediate precisions were below 2 %. The LOD and LOQ were 40 and 120 ng/zone, respectively. The average recovery was 98.6 %.

J. Planar Chromatogr. 29, 227-228 (2016). HPTLC of carbaryl in visceral sample on silica gel with hexane – ethyl acetate 9:1. Detection by spraying with 10 % NaOH solution followed by a mixture of a 10 % aqueous sodium bromide solution and a 10 % aqueous copper chloride solution (mixture ratio most likely 1:1, however, not reported). The hRF value for carbaryl was 51.

Food Chem. 221, 1232-1244 (2017). Review of novel analytical methods for the detection of milk adulterants, including the use of RP-TLC for the determination of vegetable oils as adulterant of fat content. In this methodology, vegetable oil content was quantified by monitoring the structure of sterols by using β-sitosterol as a marker.