Adsorption of estrogens on laboratory materials and filters during sample preparation.

Despite improvements in analytical techniques for detecting hormones, such as estrogen in environmental samples, there is conflicting information regarding sample filtration before analyses. In addition, there is little information about estrogen adsorption onto other common laboratory materials, including glass, plastic, or stainless steel. Therefore, we have quantified the adsorption of three different types of estrogen (estrone [E1], 17alpha-ethynylestradiol [EE2], and 17beta-estradiol [E2]) onto 11 different types of filters and six other types of materials used for sample storage and laboratory experiments. We observed significant (p < 0.05) differences in the amount of estrogen adsorbed to the different filters. Glass fiber filters adsorbed the lowest amount, whereas nylon filters adsorbed nearly all of the estrogen that contacted them during filtration. Stainless steel and polycarbonate also adsorbed significant amounts of E1, E2, and EE2. The materials with which estrogen comes into contact should be chosen carefully to avoid potential losses due to sorption.