Food Chem. 95, 58-64 (2006). HPTLC of nicotinic acid (1) and pyrazole-3(5)-carboxylic acid (2) of Volvariella volvacea on silica gel with chloroform – methanol 17:3 with one drop of formic acid added. Quantitative determination by absorbance measurement at 190 nm for (1) and 262 nm for (2). The hRf values for (1) and (2) were 30 and 40, respectively. Linearity was between 400 and 7000 ng/zone (1) and 200 and 2500 ng/zone for (2). The limits of detection and quantification were 50 and 400 ng/zone for (1) and 20 and 200 ng/zone for (2). Recoveries of both compounds were between 96 and 102 %.

CBS 100, 2-5 (2008). HPTLC of photodegraded UV filters and sunscreen on silica gel LiChrospher prewashed with methanol. AMD 2 development of UV filter standards photodegradation products with diisopropylether - n-hexane in 6 steps over 50 mm without preconditioning, and of sunscreen samples photodegradation products with t-butylmethylether - n-hexane in 7 steps over 50 mm with preconditioning, followed by drying at 120 °C for 30 min. Detection at 254 and 366 nm, followed by biodetection via dipping the plate in a Vibrio fischeri solution for 1 s and evaluation with the Bioluminizer (exposure time 55 s). Densitometric evaluation by multi-wavelength scan at 200-400 nm.

LC-GC Europe 18, 482-488 (2005). Contact Bioautography: Antimicrobials diffusion from a TLC plate to an inoculated agar plate.The chromatogram is placed face down onto the inoculated agar layer and left for some minutes or hours for diffusion. After removing the plate the inhibition zones are observed on the agar surface in the places where the spots of antimicrobials are stuck to the agar. The method resembles a disk assay. Immersion Bioautography: The chromatogram is covered with a molten, seeded agar medium. After solidification, incubation and staining (usually with tetrazolium dye) the inhibition or growth bands are visualized. Direct Bioautography: A developed plate is dipped in the suspension of microorganisms growing in a suitable broth or this suspension is sprayed onto the plate. The plate is incubated and microorganisms grow directly on it. It can be performed with Photobacterium phosphoreum (Vibrio fischeri) suspension. Bioautography systems and coupling possibilities are presented.

Phytochem. Anal. 20, 177-190 (2009). TLC and HPTLC of polyphenols (tellimagrandins I and II, rugosins A, B, D and E and other) in commercially available products of meadowsweet (Filipendula ulmaria) and dog rose (Rosa canina) on silica gel, LiChrospher Si 60, RP-18 and amino phase with tetrahydrofuran - acetonitrile - water 3:1:1, of tannins on amino phase with acetone - formic acid 3:1, of flavonols with acetone - formic acid 17:3, of tannins with diisopropyl ether - acetone - formic acid - water 4:4:1:1, and of flavonols with diisopropyl ether - acetone - formic acid - water 5:3:1:1. Detection of polyphenolic compounds under UV light at 254 and 366 nm before and after spraying with natural products reagent followed by polyethylene glycol reagent. Detection in white light after spraying with 1 % iron(III) chloride (for tannins and phenolic acids), vanillin-hydrochloric acid (flavonols) or bis-diazotised sulfanilamide (for all polyphenols). Quantitative determination of polyphenol contents by HPLC with UV detection. Meadowsweet flowers and rose hips with seeds yielded 55.5-124.8 and 0.4-1.3 mg/g of ellagitannins, respectively. The sum of detected polyphenols was 83.9-165.7 mg/g for Filipendulae ulmariae flos and 1.2-2.7 mg/g for Rosae pseudo-fructus cum fructibus.

J. Planar Chromatogr. 23, 94-103 (2010). This review describes available data on analysis of carotenoids by TLC. Petroleum ether, acetone, and hexane are the major mobile phases used for TLC. This technique was found to have the potential to be the first choice for analysis of carotenoids in biological samples. The uses of other, orthogonal chromatographic methods, for example HPLC, MS, scanning densitometry, and image analysis with TLC can enable precise analysis of carotenoids. The review consists of the following parts: 1. Introduction; 1.1 Function of carotenoids; 1.2 Occurrence of carotenoids; 2. Analysis of carotenoids; 2.1 Sampling; 2.2 Sample preparation; 2.3 Extraction of carotenoids; 2.4 Saponification; 2.5 Chromatographic analysis; 3. Thin-layer chromatographic analysis of carotenoids; 3.1 TLC of carotenoids from microbial and animal sources; 3.2 TLC of carotenoids from plant sources; 3.3 Normal-phase TLC analysis of carotenoids; 3.4 Reversed-phase TLC analysis of carotenoids; 3.5 TLC analysis of carotenoids with scanning densitometry; 4. Advantages of TLC in carotenoid analysis; 5. Conclusion and future studies. 134 References.

Chinese J. Food Sci. 29 (4), 291-295 (2008). HPTLC of celery extracts on silica gel with chloroform - methanol - water 360:46:7. Detection and identification of the flavonoids by the characteristic chemical reaction colors and the UV spectrum of the prepared samples. Quantitative determination of apigenin by absorbance measurement at 345 nm. The linearity was between 330 and 990 ng/zone. Precision ( % RSD) was 1.33 % (n = 5) and the recovery was 97.8 % (n = 5, RSD = 2.3 %).

CBS 105, 13-15 (2010). HPTLC of PVC foil samples on silica gel with isooctane – toluene – diethyl ether – ethyl acetate 8:7:4:1 after chamber saturation for 10 min, up to a migration distance of 65 mm. Detection of the biological activity of any compound migrated from the plastic foils in migration studies by dipping in Vibrio fischeri bacteria suspension and documentation with the Bioluminizer. Also direct extraction of additives from plastic foils by the TLC-MS Interface coupled to an Agilent LC-MS system and recording of the eluted additives in the positive ESI mode. Exact masses of unknowns were calculated with MassWorks software allowing their improved specification and thus their confirmation.

E-Journal of Chemistry 7(51), 5559-5565 (2010). TLC of sucralose in commercially available tabletop sweeteners, dietetic sweets and soft drinks on silica gel with chloroform - methanol - toluene 10:7:3 (system 1) and chloroform - ethanol - benzene 5:3:2 (system 2). The hRf value of sucralose was 62 with system 1 and 45 with system 2. Detection by dipping in rhodamine-sulphuric acid reagent, followed by heating at 120 °C for 3 min. The band corresponding to sucralose appears as olive-green band with ?max at 456 nm. The fluorescence property of the sucralose derivative can be used for quantitative analysis (?max 366 nm). The method is highly reproducible as other carbohydrates and artificial sweeteners don’t produce a fluorescent olive-green color with this reagent. The method was applied to cola drinks, lemon juices, sugar free sweets, and tabletop sweeteners with excellent results. The LOD was 5-7 ng/band and linearity was in the range of 40-250 ng/band for both methods.