Bovine Colostrum: Determination of Naturally Occurring Steroid Hormones by Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)
The aim of this study was to collect further data about levels of endogenous hormones in foodstuffs derived from animal production. Because of expected higher concentrations of especially estrogens in colostrum compared to other foodstuffs, our investigation focused on this matrix. For evaluation of endogenous steroid hormones in separated colostrum (fat and defatted fraction) and colostrum powder, the relevant free and conjugated estrogens (estradiol-17β, estradiol-17α, estrone, and estriol) androgens (androstendione, 19nor-androstendione, 19nor-testosterone-17β, 19nor-testosterone-17α, testosterone-17β, and testosterone-17α), and progesterone were determined by means of liquid chromatography-tandem mass spectrometry (LC-MS/MS). Upmost determined concentrations were found in the fat fraction, with 25.56 and 7.59 μg/L for estrone and androstendione, respectively. In defatted milk and colostrum powder, conjugated estrogens dominated, whereas total (free and conjugated) estrone (5.51 μg/L; 15.0 μg/kg) exceeded estradiol-17α (2.66 μg/L; 7.5 μg/kg) and estradiol-17β (2.28 μg/L; 3.3 μg/kg). Neither 19nor-steroids nor estriol were detected in colostrum fractions or processed colostrum.
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- "of colostrum exceeds the concentrations published for other products , such as meat , milk and milk products ( Farke et al . 2011 ) . Besides , within the colostrum , the higher concentrations are found in the fat fraction , as it can be observed in Table 4 . As hormonal levels in colostrum are , in general , beyond those in other foodstuffs ( Malekinejad et al . 2006 ; Courant et al . 2008 ) , this kind of milk and its products should be strongly considered when "
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ABSTRACT: Hormones work in harmony in the body, and this status must be maintained to avoid metabolic disequilibrium and the subsequent illness. Besides, it has been reported that exogenous steroids (presence in the environment and food products) influence the development of several important illnesses in humans. Endogenous steroid hormones in food of animal origin are unavoidable as they occur naturally in these products. The presence of hormones in food has been connected with several human health problems. Bovine milk contains considerable quantities of hormones and it is of particular concern. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, based on hydroxylamine derivatisation, has been developed and validated for the quantification of six sex hormones in milk [pregnenolone (P₅), progesterone (P₄), estrone (E₁), testosterone (T), androstenedione (A) and dehydroepiandrosterone (DHEA)]. This method has been applied to real raw milk samples and the existence of differences between milk from pregnant and non-pregnant cows has been statistically confirmed. Basing on a revision of existing published data, it could be concluded that maximum daily intakes for hormones are not reached through milk ingestion. Although dairy products are an important source of hormones, other products of animal origin must be considered as well for intake calculations.
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ABSTRACT: This study developed and validated a sensitive analytical method for simultaneous screening of four classes of endocrine-disrupting chemicals (i.e. progestogens, androgens, oestrogens and phenols) in milk and powdered milk using ultra-performance liquid chromatography (UPLC) coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry (QTOF-MS). Dansylation of oestrogens and phenols enhanced the ionisation efficiency and shifted the ionisation mode from negative to positive, which allowed for the simultaneous analysis of four EDCs in one chromatographic run. An efficient sample pre-treatment minimised the matrix effects. The mass errors for the precursor and product ions for 26 target compounds varied between -2.8 and 2.3 mDa; and the limits of detection (signal-to-noise ratio = 3) for milk and powdered milk were less than 0.04 µg l(-1) and 0.10 µg kg(-1), respectively. The proposed method was successfully used to analyse multiple types of real samples, including normal temperature whole milk, infant formula and whole powdered milk. In 11 samples, two target compounds, progesterone and androstenedione, were detected. The progesterone concentrations ranged from 8.1 to 12.7 µg l(-1) in milk, and from 1.2 to 32.0 µg kg(-1) in infant formulas and whole powdered milks. The androstenedione concentrations varied from 0.39 to 0.79 µg l(-1) in milks, and from 0.29 to 1.2 µg kg(-1) in infant formulas and whole powdered milks. Two post-target compounds, one isomer of oestriol and 5α-dihydroprogesterone, were tentatively identified by post-target analysis in two of 11 real samples.
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ABSTRACT: In this work, a simple and fast sample pretreatment method was proposed for determination of steroid hormones in fish tissues by coupling dynamic microwave-assisted extraction with salting-out liquid-liquid extraction. The steroid hormones were successively extracted with acetonitrile and water under the action of microwave energy. Subsequently, the extract was separated into an acetonitrile phase and an aqueous phase with ammonium acetate. The acetonitrile phase containing the target analytes was concentrated and determined by LC-MS/MS. The limits of detection for the steroid hormones were in the range of 0.03-0.15 ng g(-1). This method was successfully applied to analyze seven kinds of fish tissues, and the recoveries of the steroid hormones for the spiked samples were in the range of 75.3 ± 4.9% to 95.4 ± 6.2%. Compared with the traditional method, the proposed method could reduce the consumption of the organic solvent, shorten the sample preparation time, and increase the sample throughput.
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