This method is particularly good for general water samples, such as river, tap, holy water, etc... Large water samples tend to be extremely dilute and/or contain other particles and microbes that would interfere with your detection method (assuming it is YES-HER yeast). Therefore the DIY Vacuum Pump Solid Phase Extraction is a necessary step prior to detection. This method was adapted from a Portuguese paper that listed detailed instructions on materials and construction of such a device. We hacked it by replacing the expensive, lab-grade cartridges with cigarette filters. Turns out, cigarette filters are made of pure cellulose acetate (you know this because they dissolve to liquid when you pour acetone on them), which is a great nonpolar substrate. After running the solid phase extraction, the sex hormones will be trapped inside the filters which you would then need to elute with methanol. Make sure the methanol evaporates before running detection with YES-yeast.

First prototypes during Interactivos'16?: Possible Worlds in Madrid, Spain with  collaborators: Byron Rich, Gaia Leandra, Paula Pin, Amanda Padilla, and Carlos Gamez

Experiments extracting hormonal molecules from river samples in Kali Code, the most heavily polluted river in Yogyakarta, Indonesia