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.

J. Planar Chromatogr. 26, 402-408 (2013). HPTLC of 17alpha-ethinylestradiol (1) and 17beta-estradiol (2) and estrone (3) on silica gel with chloroform - acetone - petroleum 11:4:5. The method was combined with the Yeast Estrogen Screen for the detection of estrogenic activity in aqueous samples. Quantitative determination by absorbance measurement at 366 nm. The hRf values of compounds (1) to (3) were 60, 50 and 67, respectively. LOD for (2) was 5 pg/zone.

Food Addit. Contam. 4, 415-427 (1987). HPTLC of 17ß-estradiol, DES, zearalanol (zeranol), zearalenone and their metabolites estrone etc. on silica with methyl chloride - methanol - isopropanol 97:1:2. Detection by exposure to iodine vapor and spraying with 1% starch solution. Detection limit, 4 ng.

J. Planar Chromatogr. 26, 395-401 (2013). HPTLC of 17alpha-ethinylestradiol (1), 17beta-estradiol (2) and estrone (3) on silica gel with chloroform - acetone - petroleum 11:4:5. The method was combined with the Yeast Estrogen Screen for the detection of estrogenic effects in sediment extracts of a river. Quantitative determination by absorbance measurement at 320 nm. The hRf values of compounds (1) to (3) were 74, 61 and 84, respectively.LOD and LOQ were calculated for the estrogenic model compound (1): LOD was 0.46 pg without prior development of the TLC plate and 0.48 pg after development, LOQ was 0.8 pg without development and 1.6 pg after development.