Evaluation of mesoporous silicas functionalized with C18 groups as stationary phases for the solid‐phase extraction of steroid hormones in milk

Abstract

In this work, two mesoporous silicas functionalized with C18 groups (SM-C18 and SBA-15-C18) have been synthesized for their evaluation as stationary phases in SPE for the extraction and preconcentration of seven steroid hormones (estrone, estradiol, estriol, ethinyl estradiol, diethylstilbestrol, testosterone, and progesterone ) from milk. The characterization of both materials by diverse techniques such as transmission electron microscopy, SEM, thermogravimetric analysis, X-ray diffraction, and adsorption-desorption isotherms showed that the mesoporous silicas had a high surface area, high pore volume, and a homogeneous distribution of the pores and that both silicas presented a similar degree of functionalization. An analytical methodology for the simultaneous separation of the seven selected steroids by HPLC-DAD was developed. Both silicas were evaluated as stationary phases in SPE for the extraction of the steroid hormones from milk. This HPLC-DAD method was applied to the analysis of all extracts obtained in the SPE experiments, showing that from the two synthesized mesoporus silicas, SBA-15-C18 silica enabled the extraction of the seven compounds with recoveries between 88 and 108% for all except for estriol, for which a recovery of 62% was obtained. The analytical characteristics of this methodology were evaluated, showing good precision and linearity (R2 > 0.994) for all analytes. The comparison of the results obtained with this silica and those obtained with commercial C18 particles and with some other commercial cartridges usually employed in the extraction of steroids showed that SBA-15-C18 silica was able to extract the seven steroids with higher recovery values.

A novel hybrid mesostructured silica for the solid-phase extraction of estrogenic hormones from waters

“…The structures of the analytes investigated are shown in the ESI (see Fig. 20 Since the carbon loading of SBA-15-C 18 and ExtraBond® C 18 sorbents was similar (17% C), the better results achieved with the rst sorbent can be attributed not only to its higher loading by the C 18 groups (L 0C 18 ¼ 0.69 mmol g À1 ) but also to its uniform surface coverage and better accessibility to these groups. ExtraBond® C 18 is a reversed-phase packing material commonly used in SPE when aqueous samples are involved.…”

Preparation of porous polymers based on high internal phase emulsion for enrichment of estrogens in urine

“…Sample preparation strategies of estrogens were vital because of complex matrix and failure directly detecting in real sample. Several sample preparation methods including LLE [6], SPE [7], and solid‐phase microextraction (SPME) [8] were commonly used. In these methods, SPE were widely applied because of its efficient matrix clean‐up function and adjustability in adsorbents.…”

A bioinspired polydopamine approach toward the preparation of gold‐modified magnetic nanoparticles for the magnetic solid‐phase extraction of steroids in multiple samples

“…Therefore, the determination of the levels of sex hormones in biological fluids, such as plasma and urine, is very important . Furthermore, with regard to animal husbandry, it is well known that some natural or anabolic steroids have been forbidden to promote growth and to increase muscle size of animals in both the European Union and Asia because of their potential toxic and carcinogenic effects on public health . Meanwhile, the estrogenic and progestational chemicals excreted by humans and animals have become one of the main sources of steroid hormones in aquatic environments, which may do harm to the normal secretion of endocrine system as well as aggravate the public health hazard .…”

“…So far, there are mainly two categories of methods generally used for the determination of steroid hormones in various samples, including immunoassays as well as chromatographic methods. Different chromatographic analytical technologies based on open tubular capillary electrochromatography , MEKC , GC–MS , and HPLC coupled with diode‐array detection and MS have been developed. Although immunoassays are sensitive, the cross‐reactivity and lot‐to‐lot variation of antibodies often lead to the decrease of specificity and accuracy of the methods .…”