Isolation and detection of steroids from human urine by molecularly imprinted solid-phase extraction and liquid chromatography

Selective determination of trace 17β-estradiol in dairy and meat samples by molecularly imprinted solid-phase extraction and HPLC

“…But polymers obtained from bulk polymerisation need time-consuming processes such as crush, ground and sieve to produce irregular particles, which are not preferable for utilisation as separation media due to low packing quality, channel formation, and low number of theoretical plates. Furthermore, concentrations of E2 in dairy and meat samples are about ng kg À1 , much less than the detection limit (lg L À1 ) of the reported off-line MISPE combined with HPLC methods (Gadzała-Kopciuch et al, 2009;Jiang et al, 2009b). Therefore, further evaluation of the potential application of MISPE combined with HPLC to detect trace E2 in dairy and meat samples is necessary.…”

“…GC-MS methods are sensitive, accurate and more accessible, but derivatization is needed (Fuh, Huang, & Lin, 2004;Courant et al, 2007Courant et al, , 2008. HPLC assay is simple, rapid and widely available in most laboratories, but with limited sensitivity (Henricks et al, 2001;Jiang et al, 2009aJiang et al, , 2009bGadzała-Kopciuch, Ricanyová, & Buszewski, 2009). In order to reduce the detection limits of HPLC, effective enrichment of trace E2 from large amount of samples is very important.…”

“…Furthermore, MIPs have advantages such as physical robustness, high strength, resistance to elevated temperatures and pressures, and inertness towards organic solvents, acids or bases (Pichon, 2007;Pichon & Chapuis-Hugon, 2008;Tamayo et al, 2007). Recently, E2 imprinted MIPs prepared by bulk polymerisation have been used in off-line MISPE combined with HPLC to determine E2 in spiked fishery samples (Jiang et al, 2009b), and in human urine samples (Gadzała- Kopciuch et al, 2009). On-line MISPE combined with LC-MS have also been used to detect E2 in river water (Watabe et al, 2006).…”

Synthesis of Carbon Nanotube Incorporated Molecular Imprinted Polymer with Binding Affinity towards Testosterone

“…In humans TSN is produced naturally in both sexes, but women have much higher concentration [9]. Testosterone is required for the normal functioning and native circulation in the human body, but carcinogenic effects are possible at enhanced levels [10]. Testosterone presents several binding sites capable of interacting via H-bond with the amide and carboxyl groups of the synthesised polymers.…”

“…Due to the ease of collection and the voluminous presence of metabolites, urine specimens constitute ideal material for human studies. These compounds are present in urine at very low concentration levels (ngmL −1 ) [10]. The present paper deals with the investigation of the binding capacity and the influence of carbon nanotube on the binding of testosterone.…”