ABSTRACT
The aim of this study was to develop an efficient, sensitive and reliable analytical method for the determination of traces of steroid hormones (including oestrogen, androgens and progestagens) and corticosteroids in soil. A method of sample preparation involving pressurized liquid extraction (PLE) and solid-phase extraction (SPE) was developed for the determination of six steroids and five corticosteroids in soils, followed by analysis by liquid chromatography-tandem mass spectrometry. The conditions employed for PLE involved acetone/methanol (50:50) as the extracting solvent, a temperature of 80 degrees C, two cycles and a static time of 5 min. The extraction was followed by a SPE clean-up based on a polymeric phase. With use of protocol, a residual matrix effect was, however, highlighted. The limit of detection in soil was 0.08-0.89 ng/g for steroids and 0.09-2.84 ng/g for corticosteroids.
Subject(s)
Adrenal Cortex Hormones/analysis , Chemistry Techniques, Analytical/methods , Hormones/analysis , Soil/analysis , Chemistry Techniques, Analytical/standards , Chromatography, Liquid/methods , Limit of Detection , Methods , Soil Pollutants , Solid Phase Extraction/methods , Steroids/analysis , Tandem Mass Spectrometry/methodsABSTRACT
The role of vertebrate-like sex-steroids (testosterone, T, progesterone, P, and 17beta-estradiol, E2) in molluscs is still debated, but they could represent potential biomarkers of endocrine disruption. A radioimmunoassay (RIA) and a liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) methods have been developed and compared to measure their levels in a gastropod snail Potamopyrgus antipodarum. Both methods showed a good reproducibility despite the complex matrix and the very low levels of vertebrate-like sex-steroids. Only T and P were detected using the LC-MS/MS method, while the RIA method reached lower detection limits and enabled the detection of all three steroids. Results indicated that T and P were mainly present as unconjugated forms. Both methods were compared in the analysis of snails exposed to waste water treatment plant effluents and led to the same conclusions concerning the modulation of steroids levels. Moreover, they both were in agreement concerning T measurements. On the other hand, LC-MS/MS appeared to be more suitable when analyzing P levels due to a low sensitivity of the RIA method. As E2 was not measured using the LC-MS/MS method because of a higher detection limit compared to the other steroids, the results obtained with the RIA method should be interpreted with caution. LC-MS/MS remains the gold standard for sex-steroid determinations, however a relevant and alternative method based on RIA was developed, requiring fewer organisms. RIA seems a promising method as a screening tool for experimental use, allowing comparison of sex-steroid levels in the mudsnail both in laboratory and in field experiments.
Subject(s)
Chromatography, Liquid/methods , Gastropoda/chemistry , Radioimmunoassay/methods , Steroids/analysis , Tandem Mass Spectrometry/methods , Animals , Environmental Exposure , Estradiol/analysis , Linear Models , Progesterone/analysis , Reproducibility of Results , Sensitivity and Specificity , Testosterone/analysis , Water Pollutants, ChemicalABSTRACT
Amino acid analysis of honey by high-performance liquid chromatography (HPLC) was used first to discriminate different botanical origins and then to combat adulteration. Pure honeys of seven selected floral varieties were examined. A principal component analysis (PCA) was carried out on the results after selection of the most discriminating parameters. Lavender honeys were thus perfectly characterized, but complete satisfaction was not obtained with the six other varieties. This method (analysis by HPLC and statistical processing by PCA) enabled us to detect the addition of sugar syrup to rape and fir honeys.
