The planar yeast estrogen screen (p-YES) can serve as a highly valuable and sensitive screening tool for the detection of estrogenic compounds in various sample matrices such as water and wastewater, personal care products and foodstuff. The method combines the separation of sample constituents by thin layer chromatography with the direct detection of estrogenic compounds on the surface of the HPTLC-plate. The previous protocol using the immersion of a normal phase silica HPTLC-plate in a cell suspension for bio-autography resulted in blurred signals due to the accelerated diffusion of compounds on the wet surface of the HPTLC-plate. Here, the application of the yeast cells by spraying on the surface of the HPTLC-plate is described as an alternative approach. The presented method for the hyphenation of normal phase thin layer chromatography with a yeast estrogen screen results in much sharper signals compared to reports in previous publications. Satisfying results were achieved using cultures with cell densities of 1000 FAU. Due to the reduced signal broadening, lower limits of quantification for estrogenic compounds were achieved (Estrone (E1) = 2 pg/zone, 17β-estradiol (E2) = 0.5 pg/zone, 17α-ethinylestradiol (EE2) = 0.5 pg/zone and Estriol (E3) = 20 pg/zone). As demonstrated, it is possible to characterize profiles of estrogenic activity of wastewater samples with high quality and reproducibility. The improved sensitivity opens the stage for applications using native samples from waste- or even surface water directly applied on HPTLC-plates without the need for prior sample treatment by e.g. solid phase extraction.

平面酵母雌激素筛选（p-YES）可以作为一种非常有价值和灵敏的筛选工具，用于检测各种样品基质（例如水和废水，个人护理产品和食品）中的雌激素化合物。该方法将通过薄层色谱分离样品成分与直接检测HPTLC板表面上的雌激素化合物相结合。使用正相硅胶HPTLC板浸入细胞悬浮液进行生物自显影的先前方案由于化合物在HPTLC板的湿表面上的加速扩散而导致信号模糊。在此，将通过喷雾在HPTLC板的表面上而施加酵母细胞的方法描述为替代方法。与以前的出版物中的报道相比，使用酵母雌激素筛查法进行正相薄层色谱联用的方法所产生的信号更加清晰。使用细胞密度为1000 FAU的培养物可获得满意的结果。由于减少了信号展宽，因此降低了雌激素化合物的定量下限（Estrone（E1）= 2 pg / zone，17β-estradiol（E2）= 0.5 pg / zone，17α-ethinylestradiol（EE2）= 0.5 pg / zone和Estriol（E3）= 20 pg / zone）。如所证明的，有可能以高质量和可再现性表征废水样品的雌激素活性。更高的灵敏度为使用来自废水或什至是地表水的天然样品直接应用于HPTLC板上的应用打开了舞台，而无需事先进行样品处理，例如通过