Click Isotope Mass Probe for Highly Selective Determination of Trace Steroid Hormones in Food Samples

Abstract

Matrix effects are a great challenge for the quantitative analysis of complex food samples by liquid chromatography-tandem mass spectrometry analysis (LC-MS/MS). Stable isotope labeling (SIL) has been widely used as an effective strategy to eliminate matrix effects. Herein, a copper­(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click-reaction-based SIL method was proposed for a highly sensitive and selective determination of six synthetic steroid hormones in three different food samples (milk, yogurt, and eggs) by high-performance liquid chromatography (HPLC)-MS/MS. A pair of novel SIL agents, N-(2-azidyl ethyl) aniline (d 0-AEA) and d 5-N-(2-azidyl ethyl) aniline (d 5-AEA) were synthesized to label steroid hormones in the samples and standard solution, respectively. The reaction accomplishes in 30 min at 60 °C. The heavy labeled standards were used as internal standards (ISs), which experience the identical ionization processes with light labeled samples to minimize matrix effects. After derivatization, the ionization efficiencies of steroid hormones were greatly improved by 2–54-folds, and the matrix effects ranged from 88.6 to 99.8%. The established method achieved satisfactory detection limits (0.1–2.5 μg L–1) and high recoveries (85–102%). These results demonstrated that the proposed method holds unique advantages for trace steroid hormones analysis in foodstuffs.

Click Chemoselective Probe with a Photoswitchable Handle for Highly Sensitive Determination of Steroid Hormones in Food Samples

“…Endocrine disrupting steroid hormone residues in food, mainly including sex steroid hormones and adrenocortical hormones, have emerged as a serious risk to human health in recent decades. , It has been reported that excess steroid hormones illegally added to animal feed might remain in animal tissues due to their inherent lipophilic property. − These compounds are likely to be transferred and accumulated into the human body via the food chain, resulting in various diseases like osteoporosis, cardiovascular diseases, immune/inflammatory diseases, and breast, ovarian, and prostate cancers. − In addition, synthetic steroid hormones usually exhibit increased disrupting potency because they bind to hormone receptors with a higher affinity than the natural counterpart, for instance, the binding affinity of synthetic ethinylestradiol (EE2) to the estrogen receptor is 2-fold higher than the natural 17β-estradiol (E2) in humans. , To ensure the health and safety of consumers, it is essential to develop effective analytical methods for determining steroid hormone residues in food samples.…”

“…The methods for detecting steroid hormones often involved high-performance liquid chromatography coupled with UV detection (HPLC-UV), HPLC coupled with fluorescence detection (HPLC-FLD), , gas chromatography–mass spectrometry (GC-MS), , and liquid chromatography-mass spectrometry (LC-MS). ,,− Among them, liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique is a preferred choice for steroid hormones analysis since it possesses higher sensitivity and the ability to qualitatively and quantitatively monitor multiple analytes. ,, However, the poor ionization efficiency of some steroid hormones and their low concentration in real samples have significantly restricted the sensitivity and efficiency of using LC-MS/MS alone. , Recently, the functional group-targeted chemical labeling strategy has been developed, in which many chemoselective probes such as dansyl chloride, ( O -(3-trimethylammoniumpropyl) hydroxylamine) bromide (QAO reagent), 2-fluoro-1-methylpyridinium p -toluenesulfonate (FMPTS), , and Girard P have been used to enhance the responses of steroid hormones in the mass spectrum and further improve their detection sensitivity. The commonly used probes such as dansyl chloride and FMPTS usually serve as a hydroxyl group-targeted probe.…”

“…The Cu­(I)-catalyzed azide–alkyne cycloaddition (CuAAC) reaction is a well-known click reaction with high efficiency and good selectivity for ethynyl groups and the ability to yield a single product under mild conditions, , which is an ideal labeling reaction for ethynyl-containing steroid hormones. Based on this ethynyl group-targeted chemical labeling strategy, recently, Li et al utilized N -(2-azidyl ethyl) aniline as a chemoselective probe to label six synthetic steroids in milk, yoghurt, and egg samples, which introduced a N atom in the labeled products to further improve their detection sensitivity in HPLC-MS/MS analysis. Inspired by this, we have designed and synthesized a novel chemoselective probe Azo-N 3 in this work; the chemical structure of the probe Azo-N 3 comprises four main parts as illustrated in Scheme : the reactive site N 3 (blue), an imidazolium salt-based MS tag (orange) to improve the MS ionization efficiency and water solubility of the probe, a multifunctional linker (red) that connects the reactive site to the MS tag, and an azobenzene-based photoswitchable handle (green).…”

Benzoyl isothiocyanate modified surface of silica gel as the extraction material for adsorbing steroid hormones in water

“…17 The pretreatment method is determined by the state of the sample, mainly including solid-phase extraction (SPE), liquid-phase extraction, liquid–liquid extraction, and their derived extraction methods. 18 For different environmental matrices, researchers have developed a variety of extraction materials for the extraction of steroid hormones combined with gas chromatography-mass spectrometry (GC-MS), 19 high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), 20 and biosensing technologies. 21 Thus, an efficient pretreatment method is extremely important for the detection of steroid hormones.…”