Influence of Soil Properties and Test Conditions on Sorption and Desorption of Testosterone

Abstract

In this study, batch sorption and desorption experiments were conducted for testosterone using four agricultural soils and five clay minerals. Significant differences in sorption behavior were observed between abiotic and biotic systems. The Freundlich sorption coefficient K f ðμg=gÞ=ðμg=mLÞ n ranged from 8.53 to 74.46 for soils and from 35.28 to 1,243 for clays. The maximum sorption capacity (μg=g) of soils ranged from 25.25 to 440.61 for soils and from 168.46 to 499.84 for clays. Correlation of the sorption model parameters with the soil properties indicated that both clay content and soil organic matter are important variables in predicting testosterone sorption behavior. Observed testosterone desorption from agricultural soils ranged from approximately 14 to 100% after three desorption cycles, and the desorption percentage decreased as the initial testosterone concentration decreased. It was determined that the temperature, ionic strength, water/soil ratio, and soil depth influenced the sorption and desorption of testosterone. Desorption significantly increased with the soil depth (p < 0.05) and with the increase in the water/soil ratio. Temperature had an inverse effect on the sorption capacity of the soils tested. Thermodynamic calculations showed that the enthalpy change (ΔH 0 ) of the soils tested ranged from 12.9 to 20.7 kJ=mol, indicating a weak interaction between the testosterone and soil. The authors' results suggest that additional studies on how soil particles with different size fractions affect hormones' fate and transport are needed to determine the potential risk of testosterone leaching or runoff.

Sorption of testosterone on partially-dispersed soil particles of different size fractions: Methodology and implications

“…Testosterone was selected as the representative hormone because 1) it is a prototype for other synthetic androgenic hormones (Kanayama and Pope 2012); 2) little is known about the F/T of androgenic hormones (Casey et al, 2004); and 3) it was used previously (Qi et al, 2014;Qi and Zhang 2015a;Ma et al, 2015). In the present study, sorption tests were conducted with testosterone at environmentally relevant low concentration levels (20−150 ng/L) (Finlay-Moore et al, 2000).…”

Effect of rainfall timing and tillage on the transport of steroid hormones in runoff from manure amended row crop fields

“…On the contrary, sorption is inversely proportional to desorption. Ma et al [19] studied the desorption capacity of testosterone in the same soil and found less than 10% desorption after first cycle of analysis which indicated low desorption of testosterone in the soil-water systems especially if it was sorbed on top soil or on a soil with high clay content. A greater OM content caused stronger binding of testosterone with soil and resulted less desorption.…”

“…Both natural and synthetic hormones and their metabolites have been detected in manure, soil and wastewater of cattle feedlots [13][14][15][16]. Studies evaluating the persistence of specific hormones in soils observed that most steroid hormones and their metabolites exhibit relatively strong adsorption-desorption characteristics with low aqueous solubility [17][18][19]. Soil microbiology and surrounding physio-chemical characteristics are major factors controlling transformation among the steroid hormones and their metabolites.…”

Detection, Occurrence and Fate of Emerging Contaminants in Agricultural Environments

“…Ma et al (2015) suggested that clay content, soil organic matter, temperature, ionic strength, water/soil ratio, and soil depth affected the sorption and desorption of testosterone in soil. The Freundlich sorption coefficients K f of the four agricultural soils and the five clay minerals evaluated were 8.53–74.46 and 35.28–1,243 (μg/g)/(μg/mL) n , respectively.…”

“…Ma et al (2015) investigated the occurrence of 20 antibiotics during the groundwater recharge process across China. Fifteen locations employing reclaimed water located in different humid, semi-humid and semi-arid regions were identified, and samples of both reclaimed and ground water were analyzed.…”