J. Planar Chromatogr. 3, 15-19 (1990). HPTLC of 13 organic-nitrogen pesticides on silica with mixtures of hexane – dioxane 8:2, 6:4, 4:6 and 2:8. Optimization of mobile phase composition was carried out by using a comprehensive computer program written in HP BASIC 4 language. The separation of spots on the chromatograms showed agreement between predicted and experimental chromatograms.

J. Planar Chromatogr. 10, 48-54 (1997). Description of the application of TLC to the analysis of toxic metals (inorganic and organic mercury, Co, Ni, Pb, Zn, Cd, Cu, Fe, Ag, Bi, Mn, Sn, Cr, Al, Be, As, Sb) in a variety of environmental samples. The period covered is 1960 -1995. Spectrophotometry, titrimetry, AAS, densitometry, fluorimetry, and solvent extraction techniques have been combined with TLC for sensitive identification, quantification, and selective separation of toxic heavy metals present in natural, river, and sea waters, electroplating waste water, sludges, aquatic plants, cosmic dust, air, and airborne dust, etc.

J. Chromatogr. A 1218 (19), 2745-2753 (2011). HPTLC of sucralose in waste water on silica gel with isopropyl acetate – methanol – water 15:3:1. The developing time was 15 min. Detection with p-aminobenzoic acid reagent. Quantification by absorbance measurement at 400 nm. The limit of quantification was 100 ng/L at a recovery rate of 80 % and the extraction of a 0.5 L water sample. An interlaboratory trial in 2008 showed good agreement of the sucralose content determined in four water samples by HPTLC and other methods (HPLC–MS/MS or HPLC–TOF-MS). The good accuracy and high sample throughput capacity proved HPTLC as a well suited method for quantification of sucralose in various aqueous matrices.

AnaI. Letters 20, 235-257 (1987). One- and two-dimensional TLC of azo dyes of phenolic compounds in water and grain on silica with chloroform acetone 9:1 or benzene - di-n-propylamine 4:1 for 1-D TLC, and with the two solvent mixtures for 2-D TLC. Assessment by comparison of the spots with standards. Detection limit 0.005-0.2 mg.

Proc. 9th Internat. Symp. Instr. Chromatogr., Interlaken, April 9.-11., 123-128 (1997). In preparation of a German standard procedure (DIN 38407, part 7) in 1994 an interlaboratory test was performed concerning the qualitative and quantitative determination of PAH in potable water. The evaluation of this interlaboratory test with 12 participating laboratories has demonstrated the efficiency, the reproducibility, the repeatability, and the accuracy of modern quantitative HPTLC in environmental trace analysis. HPTLC of benz(ghi)perylene, indeno(1,2,3-cd)pyrene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, fluoranthene) on silica impregnated with caffeine with dichloromethane at - 20°C. After drying immersion in paraffin/hexane 1:2. Evaluation by densitometry at 366 nm (fluorescence).

Separation and determination of selenium. Proc. 6th Int. Symp. Instrum. Planar Chromatogr., (Interlaken 1991), Inst. Chromatogr., Bad Dürkheim, FRG, 137-141 (1991). Contrary to the title, was described a quantitative determination for thallium. TLC on self made ion-exchanger stannic silicate with 2M NH4Br 1:1. Detection by spraying with a solution of sodium sulfite and potassium iodide and exposition to NH3 vapor. Quantitative determination by densitometry at 420 nm.

J. Chromatogr. A 754, 333- 346 (1996). A review with 64 references on the extraction, clean-up and determination of the most widely used pesticides by using different techniques including TLC.

J. Planar Chromatogr. 24, 214-217 (2011). HPTLC of six phenolic compounds (phenol, 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, and pentachlorophenol) in water samples extracted using microliter volumes of 1-undecanolon, on RP-18 with methanol - water 2:1 in a twin-trough chamber. Detection by spraying with a mixture of iron(III) chloride and potassium ferricyanide. Quantitative determination by densitometry in absorbance mode at 254 and 725 nm. The calibration curves were linear in the range of 0.025-4.0 and 0.1-20.0 mg/band. The limits of detection and quantification were between 8-35 and 25-98 ng/band, respectively. The relative standard deviation for repeatability was between 2.6 % and 6.4 %. Recovery (by standard addition) was between 89.2-101.7 %.