J. Liq. Chromatogr. Relat. Technol. 35, 1497-1516 (2012). The authors reviewed stationary phases, solvent systems, and detection reagents developed for the analysis of amino acids. Polar and non-polar layers as well as impregnated layers mainly with metal ions and also with chiral agents were described for the separation and identification of amino acids. On the other hand, over fifty mobile phases were reviewed for the analysis of amino acids, with a recent tendency in the use of surfactants as less toxic reagents. Methodologies for the separation of amino acid enantiomers, such as the use of beta-cyclodextrin as chiral mobile phase as well as derivatization methods such as iodine azide reaction to enhance sensitivity in detection were also described. TLC has a privileged position due to its simplicity, convenience, and cost-effectiveness for separation of amino acids.

J. Planar Chromatogr. 25, 374-379 (2012). HPTLC of atazanavir sulfate (1) and ritonavir (2) in combined dosage forms on silica gel with toluene - methanol - glacial acetic acid - ethyl acetate 14:1:3:4. Quantitative determination by absorbance measurement at 254 nm. The hRf values for (1) and (2) were 50 and 63, respectively. Linearity was in the range of 30-300 ng/zone for (1) and 10-100 ng/zone for (2). The limit of detection and quantification was 16 and 49 ng/zone for (1) and 18 and 55 ng/zone for (2), respectively. The intermediate/inter-day/intra-day precision was below 0.7 % (n=6). Recovery for (1) and (2) was in the range of 99.6-100.0 %.

J. Liq. Chromatogr. Relat. Technol. 35, 2753-2764 (2012). HPTLC of melitracen hydrochloride (1) and flupentixol hydrochloride (2) on silica gel with methanol - chloroform - toluene 2:9:9 + 1 drop ammonia. Quantitative determination by absorbance measurement at 291 nm. The hRf value of compounds (1) and (2) were 53 and 34 and selectivity regarding matrix was given. Linearity was in the range of 1600-6400 ng/band and 80-320 ng/band for (1) and (2), respectively. Limit of detection was found to be 27 ng/band and 5 ng/band for (1) and (2), respectively. Limit of quantification was found to be 82 ng/band and 14 ng/band for (1) and (2), respectively. The intermediate/inter-day/intra-day precision was below 0.2 % for (1) and 1.1 % for (2) (n=3). Recovery (by standard addition) was between 99.1 and 101.8 % for both (1) and (2). The method showed comparable results with HPLC.

& Wendl. (Solanaceae) against ethylene glycol induced urolithiasis in rats. J. Ethnopharmacol. 138, 160-170 (2012). HPTLC of solasodine in the fruits of Solanum xanthocarpum on silica gel with toluene - ethyl acetate - diethylamine 12:1:1. Quantitative determination by absorbance measurement at 200 nm. The hRf of solasodine was 52.

J. Liq. Chromatogr. Relat. Technol. 35, 1565-1584 (2012). HPTLC of negundoside (1), ursolic acid (2), eugenol (3), lupeol (4), and beta-sitosterol (5) in the leaves of Vitex Negundo on silica gel with toluene - methanol 9:1. Detection by dipping in anisaldehyde sulfuric acid reagent for approximately 1 min, followed by heating at 100 °C for 5 min. Quantitative determination by absorbance measurement at 525 nm. The hRf value of compounds (1) to (5) were 47, 61, 56, 54 and 38, and selectivity regarding matrix was given. Linearity was in the range of 200-800 ng/zone for (1), 72-576 ng/zone for (2), 200-1000 ng/zone for (3), 150-900 ng/zone for (4) and 80-480 ng/zone for (5). Limits of detection and quantification were 80 and 200 ng/zone for (1), 18 and 72 ng/zone for (2), 60 and 200 ng/zone for (3), 50 and 100 ng/zone for (4) and 20 and 60 ng/zone for (5), respectively. The method provides acceptable intra-day and inter-day precision for (1) to (5). The average recoveries for compounds (1) to (5) were found to be 99.9, 100.1, 99.7, 100.0, and 99.9 %, respectively.

CBS 108, 12-15 (2012). HPTLC of anthracene (ANT), benzo[b]fluoranthene (BBF), benzo[k]fluoranthene (BKF), pyrene (PYR), acenaphthene (ACE), benzo[a]anthracene (BAA), benzo[a]pyrene (BAP), benzo[ghi]perylene (BPE), chrysene (CHR), dibenzo[a,h]anthracene (DBA), indeno[1,2,3-c,d]pyrene (IND), fuorene(FLU), fuoranthene (FLA), and phenanthrene (PHE) in toys on RP-18 phase with acetonitrile - water 9:1 by three-fold development over 45, 55 and 65 mm using automated multiple development (AMD) under nitrogen. Detection at 254 and 366 nm. Quantitative fluorescence measurement at different excitation wavelengths with cut-off filters: 220 nm/>320 nm for ACE, 250/>320 for ANT, 366/>400 for BAA and BAP, 270/>400 for BBF, BPE, BKF, CHR, DBA, FLA, IDN (after dipping in nitromethane), 250/>320 for FLU and PHE and at 270/>320 for PYR. Polynomial regression with high coefficients of correlation and low standard deviations. Coeffivients of variation for repeatability and reproducibility were below 10 %. This method allows the determination of 14 of the 16 PAHs. With LODs of 0.1-0.2 mg/kg the demands for the German GS mark (label for checked safety) are fulfilled. The results by HPTLC were comparable to results obtained by GC-MS.

CBS 108, 4-5 (2012). HPTLC of human insulin recombinant and porcine and bovine pancreas insulin on ProteoChrom silica gel with 2-butanol - pyridine - 25 % ammonia - water 39:34:10:26 to 50 mm migration distance. Detection under UV 366 nm after spraying with 0.02 % fluorescamine in acetone. Elution with the TLC-MS Interface and MS analysis in ESI positive mode, the eluent was acetonitrile - water 1:1. The hRf value of human, porcine and bovine insulin was 50. All mass spectra could be clearly assigned to the different insulin samples.

J. Planar Chromatogr. 25, 156-161 (2012). HPTLC of haloperidol (1) and metabolites I (2), II (3) and III (4) in plasma on RP-18 with methanol - 0.001 % diethylamine. Quantitative determination by absorbance measurement at 230 nm. The hRf values of haloperidol and metabolites (2) to (4) were 22, 6, 16, and 87, respectively. Recoveries for (1) to (4) were 85, 88, 87, and 77 %, respectively. LOD for haloperidol was 1.0 mg/mL and for all the three metabolites (2) to (4) it was 0.8 mg/mL.