J. Planar Chromatogr. 32, 285-294 (2019). HPTLC of ondansetron hydrochloride
dihydrate (1), granisetron hydrochloride (2) and tropisetron hydrochloride (3) in plasma samples on silica gel with chloroform - methanol - 10 % ammonia 80:20:1. Quantitative determination by absorbance measurement at 285 nm. The hRF values for (1) to (3) were 23, 63 and 76, respectively. Linearity was between 25 and 300 ng/zone for (1), 25 and 250 ng/zone for (2) and 10 and 200 ng/zone for (3). The intermediate precision was below 4 % (n=6). The LOD and LOQ were 12 and 36 ng/zone for (1), 8 and 25 ng/zone for (2), and 3 and 8 ng/zone for (3), respectively. Recovery was between 96.4 and 101.4 % for (1) to (3).

J. of China Pharm. 23 (20), 38-40 (2014). Nicotine is a toxic substance in tobacco. Studies have shown that nicotine may prevent and treat Alzheimer's disease (AD) and Parkinson's syndrome (PD). At present, the most effective method to treat AD is by inhibiting the activity of acetylcholinesterase (AChE), thus enhancing the cholinergic activity indirectly. In order to clarify the mechanism of nicotine reducing the incidence of AD, the activity of natural AChE inhibitors in Xinjiang Mohe tobacco was screened by TLC on silica gel with (A) ethyl acetate – methanol – ammonium hydroxide 70:30:1, followed by detection via enzyme inhibition (this is not bioautography, as stated in the title): firstly by spraying with 1.0 U/mL AChE (AChE 500 U + tris-HCl buffer solution of pH 7.8 500 mL + bovine serum albumin 500 mg), followed with 1.5 g/L alpha-naphthyl acetate (150 mg in ethanol 40 mL + water 60 mL) and then with 0.5 g/L Fast blue B salt, resulting in white zones on purple background; (B) toluene – ethyl acetate - diethylamine 7:2:1, detection by spraying with 0.2 mmol/L 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical reagent, resulting in white to yellow zones on pale purple background. The results indicated that nicotine in Xinjiang Mohe tobacco could bind to AChE and thus inhibit its activity.

GIT Fachz. Lab. 12, 1221-1223 (1986). Neue wasserbenetzbare HPTLC RP-18 Fertigplatten. New HPTLC RP-18 pre-coated plates wettable by water.) Description of a new HPTLC precoated plate based on silica gel with a reduced degree of modification with octadecyl groups. This plate material is fully wettable with methanol - water mixtures between 0:100 and 100:0. Running times for 50 mm are between 14 and 40 minutes, whereby the maximum running times occur with the 50:50 mixture. Separations of nicotinic acid - isonicotinic acid, of analgesics and of alkaloids.

J. of Medicinal Chemistry 32, 2432- 3435 (1989). TLC of vasotocin analogues on silica with butanol - pyridine - acetone water 15:10:3:6 or 15:10:3:12 and butanol acetic acid - water 4:1:1. Detection by exposure to chlorine followed by spraying with 1% aqueous KI-starch solution.

Proc. 6th Int. Symp. Instrum. Planar Chromatogr., (Interlaken 1991), Inst. Chromatogr., Bad Dürkheim, FRG, 401-408 (1991). Preliminary results are described for the combination of off-line TLC-FAB-MS for polar, ionisable compounds and their conjugated metabolites. HPTLC of benzoic acid, hippuric acid, phenolphthalein and its gucuronide, nitrophenol and its glucuronide and paracetamol and its sulfate on silica with chloroform - ethanol 3:2. Separated substances were removed and determinated by FAB-MS and MS-MS.

Arzneim.-Forsch./Drug Res. 45, 766-770 (1995). TLC of efonidipine hydrochloride (2-benzyl(phenyl)amino)ethyl 1,4-dihydro-2,6-dimethyl-5-(5,5-dimethyl-2-oxo-1,3,2-dioxaphosphorinan-2-yl)-4-(3-nitrophenyl)-3-pyridinecarboxylate hydrochloride ethanol) and metabolites on silica with chloroform - methanol - diethylamine 18:1:1 or chloroform - methanol 1:1. Detection under UV 254 nm.

J. Planar Chromatogr. 11, 394-399 (1998). A new simple and powerful technique, on-line sample collection after high-resolution step-wise gradient OPLC separation combined with digital autoradiography (DAR) has been used for isolation of plasma and urine metabolites of 3H- or 14C-radiolabeled deramciclane (a new anxiolytic compound). This highly efficient separation can be followed by different MS techniques (FAB-MS, FAB-MS-MS, HPLC-MS, and HPLC-MS-MS) for determination of the structures of minor and major metabolites in different biological matrices. The combination of these methods resulted in a simple, sensitive, and efficient technique for metabolite research. OPLC on HPTLC silica gel, prewashed with methanol - water 4:1 with A) chloroform - acetonitrile 3:2 and B) n-butanol - acetic acid - water 4:1:1 for the gradient. Detection by digital autoradiography.

J. Liq. Chromatogr. Relat. Technol. 41, 324-328 (2018). TLC minilab protocols were transferred to HPTLC validated methods for the determination of atenolol (1), chloramphenicol (2), furosemide (3), glibenclamide (4), penicillin V potassium (5), and praziquantel (6) on silica gel with methanol – ammonia 100:1 for (1), ethyl acetate – toluene – methanol 15:5:3 for (2), toluene – ethyl acetate – acetic acid 17:13:1 for (3), ethyl acetate – methanol – toluene – ammonia 11:7:1:1 for (4), ethyl acetate – methanol – acetic acid 20:10:1 for (5) and acetone – toluene 14:7 for (6). Qualitative evaluation under UV 254 nm. The hRf values for (1) to (6) were 35, 52, 30, 61, 48 and 65, respectively.