Phytochemistry 155, 37-44 (2018). HPTLC of pine resins collected from Abies grandis, Pseudotsuga menziesii, Picea abies, Pinus sylvestris L. and Pinus strobus L. in a forest area of The Netherlands during early and late spring on silica gel with toluene – isopropyl alcohol – diethyl ether 16:1:3. Detection by spraying with 2 mL of anisaldehyde sulfuric acid solution, followed by heating at 100 ºC for 3 min. Qualitative identification under UV light at 366 nm. Most of the metabolites detected in GC-MS were confirmed by HPTLC analysis. HPTLC proved to be an important technique for metabolic profiling.

Phytochem. Anal. 29, 452-462 (2018). HPTLC of apigenin(1), luteolin (2), kaempferol (3), quercetin (4), kaempferol‐3‐O‐glucoside (5), quercetin‐3‐O‐glucoside (6), isorhamnetin‐3‐O‐neohesperidoside (7) and rutin (8) in the fruits and aerial parts of Foeniculum vulgare (fennel), Pimpinella anisum (anise), Carum carvi (caraway), Cuminum cyminum (cumin), Coriandrum sativum (coriander), Apium graveolens (celery), Petroselinum crispum (parsley), and Anethum graveolens (dill) on silica gel with ethyl acetate – methanol – water – acetic acid 3:1:1:1. Quantitative determination by absorbance measurement at 254 nm. Heat maps and hierarchical clustering were performed for image processing. The hRF values for (1) to (8) were 97, 90, 83, 73, 30, 17, 7 and 2, respectively. LOD and LOQ were 54 and 166 ng/zone for (1), 52 and 157 ng/zone for (2), 58 and 177 ng/zone for (3), 37 and 112 ng/zone for (4), 57 and 172 ng/zone for (5), 54 and 164 ng/zone for (6), 55 and 169 ng/zone for (7) and 58 and 178 ng/zone for (8), respectively. The intermediate precision was <2 % (n=6). Average recovery was 98.4 % for (1), 92.3 % for (2), 95.3 % for (3), 96.8 % for (4), 94.5 % for (5), 95.6 % for (6), 95.1 % for (7) and 97.3 % for (8).

J. AOAC Int. 101, 1308-1313 (2018). Review of the most important aspects of the microbiological methods for the analysis of cobalamin, including the use of bioautography with a cobalamin-dependent Escherichia coli after TLC separation.

J. Planar Chromatogr. 31, 265-271 (2018). HPTLC of aspirin (1), paracetamol (2), and caffeine (3) in saliva, after ultrasound-assisted emulsification microextraction, with chloroform on silica gel with ethyl acetate - acetic acid 19:1. Detection under UV light at 254 nm. Quantitative determination using ImageJ software. The hRF values for (1) to (3) were 90, 80 and 50, respectively. Linearity ranged between 4 and 200 μg/zone for (1) to (3). LOD and LOQ were 12 and 38 μg/zone for (1), 8 and 26 μg/zone for (2), and 7 and 23 μg/zone for (3), respectively. The intermediate precision was <10 % (n=3). Recovery was in the range of 89-94 % in saliva for (1) to (3).

CBS 81, 6-7 (1998). HPTLC-AMD on silica gel with a gradient based on methanol – dichloromethane – n-hexane. Quantification by densitometry with absorbance measurement at 220 nm and fluorescence measurement at 366/>400 nm.

Acta Chromatographica 14, 70-81 (2004) .TLC of thiamine (B1), riboflavin (B2), niacin (B3), pyridoxine (B6), cobalamin (B12) ascorbic acid (C) and folic acid on silica gel and chemical bonded silica gel with 14 mobile phases, three of which giving the best separation: 1) 1-butanol - chloroform - acetic acid - ammonia - water 7:4:5:1:1, 2) benzene - methanol - acetone - acetic acid 14:4:1:1, 3) chloroform - ethanol - acetone - ammonia 2:2:1:1. Detection in visible light, under UV light at 254 nm and 366 nm. Evaluation of other detection methods such as spraying with 0.5 % ether solution of iodine - Dragendorff reagent for B1, 1 % methanol solution of 1-chloro-2,4-dinitrobenzene followed by 3 M NaOH for B3 and B6, 0.4 % methanol solution of 2,6-dichloroquinone-4-chloroimide for B6, 1:1 mixture of 2 % H2SO4 - EtOH and 0.2 % ethanol solution of p-dimethylaminocinnaldehyde for biotin. Quantification by videodensitometry. Discussion of identification of vitamins in biological samples by using different visualization method in combination with Rf values.

CBS 84, 12-13 (2000) HPTLC of synthesis product SR 94163 and impurities SR 94145 and SR 94454. Quantitative determination at 210 nm. Recovery rate for impurities is 98-114 %. For routine analysis in process control the HPLC method was substituted by the faster HPTLC method.

J. AOAC Int. 86, 909-915 (2003). In quality control and stability testing of herbal medicinal products, fingerprint chomatograms are used as powerful tools to evaluate and compare the composition of compounds in such products. To fulfill the ICH- and GMP-based regulatory requirements in pharmaceutical QC, chromatographic fingerprint analysis needs to be validated. By considering the stationary phase, sample application, developing solvents, chromatogram development, plate labeling, derivatization, documentation, and chromatographic equipment the paper provides a comprehensive concept for evaluating validation parameters for planar chromatographic fingerprinting based on a standardized methodology. Validation parameters addressed include stability of the analyte, selectivity, robustness testing, and method reproducibility.