CBS 125. HPTLC of estrogen-active compounds in a migrate of a food contact material on silica gel with chloroform - acetone - petroleum ether 11:4:5. Planar Yeast Estrogen Test (P-YES) was performed by spraying 2 mL yeast cells onto HPTLC plates, followed by incubation at 30 °C for 3 h and spraying with 2 mL 0.5 mg/mL 4-methylumbelliferyl-beta-D-galactopyranoside and incubation for 20 min at 37 °C. The method was compared with microtiter bioassay (L-YES). P-YES was more sensitive than L-YES and results can be repeated upto one year later.

J. Planar Chromatogr. 35, 189-195 (2022). Planar yeast estrogen screen (pYES) of estriol, daidzein, genistein, 17β-estradiol, 17α-ethinyl estradiol, estrone, 4-nonylphenol and bis(2-ethylhexyl) phthalate on silica gel with cyclohexane - methyl ethyl ketone 2:1 or cyclohexane - cyclopentyl-methyl ether 3:2. Detection under UV light at 272 nm.

Anal. Bioanal. Chem. 413, 1321-1335 (2021). HPTLC of estrone (1), 17β-estradiol
(2), 17α-ethinylestradiol (3), 5α-dihydrotestosterone (4), and progesterone (5) in wastewater and surface water samples on silica gel with a mixture of dichloromethane, cyclohexane, and acetone in different proportions. Detection by spraying with 8 % sulfuric acid in ethanol, followed by heating at 105 ºC for 10 min. Qualitative identification under UV light at 310 nm. Yeast multi endocrine-effect screen was performed by spraying the HPTLC plates with a mixed suspension of genetically modified Arxula adeninivorans yeast strains, which contain either the human estrogen, androgen, or progesterone receptor. The HPTLC plates were incubated at 30 ºC for 18 h and at 100 % humidity. After incubation, densitometric evaluation at: 445/K460 nm, 475/K500 nm and 542/K560 nm to determine the fluorescence of the cyan fluorescent protein (CFP, gestagen), green fluorescent protein (GFP, androgen), and DsRed2 protein (estrogen), respectively. The hRF values for (1) to (5) were 21, 22, 29, 34 and 39, respectively.

J. Liq. Chromatogr. Relat. Technol. 42, 311-316 (2019). HPTLC of equol in cattle manure with methyl t-butyl ether - cyclohexane 1:1. The plate was scanned with a Time of Flight – Direct Analysis in Real Time – Mass Spectrometry (TOF-DART-MS) system. The hRF value of equol was 71. The LOD and LOQ for equol were 2.4 µg/zone and 4.5 µg/zone, respectively. 

J. Liq. Chromatogr. Relat. Technol. 31, 555-566 (2008). Five new derivatization reagents (gentian violet, methylene violet, methylene blue, malachite green, and Janus blue) were used to detect estradiol on aluminium oxide. Barton’s reagent, rhodamine B, and sulfuric acid were used as the comparative derivatization reagents. Limit of detection, detection index, modified broadening index, modified contrast index, and linearity range were determined for estradiol after derivatization with these reagents. Quantitative determination by absorbance measurement between 200 and 600 nm.

behavior of some steroids by OPLC. Proc. Intern. Symposium on TLC with special Emphasis on OPLC, Szeged, 90 (1984). OPLC (OPTLC) of progesterone, cholesterol, corticosterone, aldosterone, cortisol, cortisone on silica with a) petrol ether - ethyl-acetate 6:4, b) chloroform - ethyl acetate - ethanol 90:10:1, c) chloroform - phenol 9:1. Detection with 50 % phosphoric acid and heating at 105 °C for 15 minutes.

J. of Practical Pharmacy & Clinic 14(2), 134-135 (2011). TLC of estrogenic hormones illegally added to traditional Chinese medicines on silica gel with chloroform - n-hexane - acetone 10:9:2. The hRf values of estrone, stilbestrol, ethinylestradiol, and estradiol were 67, 53, 48 and 39, respectively. Detection by spraying with 5 % phosphomolybdate reagent and heating at 80 ºC until the zones were detected. Identification of the four estrogens by comparison with the standards. The method is selective, sensitive, reliable, accurate, robust, and suitable for rapid screening of illegal estrogenic hormones in TCM preparations.

J. Chromatogr. 374, 221-222 (1986). TLC of 6 estrogen conjugates on C-8 silica with methanol - tetramethylammonium chloride 1:1. Detection by spraying with 10 % sulfuric acid and heating at 120 °C for 5 mm. Quantification by densitometry at 336 nm. Sensitivity 50 ng, calibration curves linear at 50 -2000 ng.