Chromatographia 69 (1-2), 151-155 (2009). HPTLC of paracetamol and caffeine on RP18W with methanol - acetic acid - water 250:43:707. Quantification by absorbance measurement at 254 nm. The limit of detection and limit of quantitation for paracetamol was 100 and 191 ng/spot and 40 and 76 ng/spot for caffeine. Recovery was in the range of 99.6 - 106.8 % and the repeatability of the method was RSD < 1.9 %.

Anal. Chem. 76, 3251-3262 (2004). This review covers the literature of TLC/HPTLC found in Chemical Abstracts and ICI Web of Science from November 1, 2001 to November 1, 2003. Review Contents: 1. History, Student Experiments, Books, and Reviews; 2. Theory and Fundamental Studies; 3. Chromatographic Systems (Stationary and Mobile Phases); 4. Apparatus and Techniques; 5. Detection and Identification of Separated Zones; 6. Quantitative Analysis; 7. Preparative-Layer Chromatography and Thin-Layer Radiochromatography 8. Literature Cited.

Anal. Chem. 79, 5793-5808 (2007). HPTLC of phospholipids (phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidic acid, cardiolipin, sphingomyelin) on silica gel in a saturated chamber with chloroform-methanol - 2-propanol - triethylamine - 0.25 % potassium chloride solution 30:9:23:18:6. Detection by dipping in molybdenum blue reagent for 1 s and quantitative evaluation by densitometry. The sensitivity was in the range of 10 to 150 pmol/spot (depending on phospholipid acidity, hRf value, and ion polarity).

Anal. Chim. Acta 577 (1), 46-51 (2006). HPTLC of trigonelline in herbal extracts and in pharmaceutical dosage forms on silica gel with n-propanol - methanol - water 4:1:4. Quantitative determination by absorbance measurement at 269 nm. Linearity was between 100 - 1200 ng/spot (via peak area) and the correlation coefficient was 0.9991. The trigonelline content of herbal extracts quantified and estimated from the formulation was found to be well within limits (± 5 %) of the labeled content of the formulations. The method is reproducible and selective for the estimation of trigonelline by statistical analysis of the data.

J. Planar Chromatogr. 22, 115-119 (2009). HPTLC of metoprolol succinate and amlodipine besylate on silica gel (prewashed with methanol) with methanol - ethyl acetate - water - toluene - 25 % ammonia 15:50:3:30:3 in a twin trough chamber saturated for 20 min at 25 +/- 2 °C. Quantitative determination by absorbance measurement at 236 nm.

Food Chem. 113, 640-644 (2009). HPTLC of curcumin (1), demethoxycurcumin (2), and bisdemethoxycurcumin (3) from the rhizomes of Curcuma longa on silica gel with chloroform - methanol 24:1. Quantitative determination by absorbance measurement at 425 nm. The hRf values of (1), (2), and (3) were 66, 48, and 30, respectively. Selectivity regarding matrix was given. Linearity was between 1 and 20 µg/spot for all curcuminoids. The intermediate precision of the method was satisfactory. Recovery was 98.7 % for (1), 96.3 % for (2), and 97.2 % for (3). The limit of detection for the substances was 100 ng/spot.

Chromatographia 65 (3-4), 239-243 (2007). TLC of solasodine in various Solanum species on silica gel with a developing solvent containing an organic acid to form ion pair complexes of solasodine with the acid dye. The resulting colored complex was quantified by absorbance measurement at 461 nm. Linearity was between 79 and 495 ng/spot with a correlation coefficient of 0.995. The method eliminates post derivatization steps and the problem of background interference. Application of the method to determine solasodine content in various herb samples, herb extract and their formulations showed an accuracy of 98.5 ± 2.8 % without matrix interference.

J. AOAC Int. 92, 1153-1159 (2009). HPTLC of sucralose on amino phase with acetonitrile - water 4:1 in a horizontal or standard development chamber without chamber saturation. For detection the plate was heated at 190 °C for 20 min, either in a drying oven or on a temperature-controlled heating plate. Quantitative determination by absorbance and fluorescence measurement at 254 nm. The results of the interlaboratory comparison show good precision characteristics. The fluorescence measurements of the sucralose derivatives indicated better method performance, compared with absorbance measurements in the UV.