Obtaining longitudinal endocrinological data from free-ranging animals remains challenging. Steroid hormones can be extracted sequentially from non-invasively sampled biologically inert keratinous tissues, such as feathers, nails, hair and whiskers. However, uncertainty regarding the type and levels of steroids incorporated into such tissues complicates their utility in wildlife studies. Here, we developed a novel, comprehensive method to analyze fourteen C19 and fourteen C21 steroids deposited chronologically along the length of seal whiskers in a single, 6-minute chromatographic step, using ultra-performance convergence chromatography-tandem mass spectrometry. The limits of detection and quantification ranged from 0.01 to 2 ng/mL and from 0.1 to 10 ng/mL, respectively. The accuracy and precision were within acceptable limits for steroids at concentrations ≥2 ng/mL. The recovery (mean = 107.5% at 200 ng/mL), matrix effect and process efficiency of steroids evaluated, using blanked whisker matrix samples, were acceptable. The method was applied to the analysis of steroid hormone levels in adult female whisker segments obtained from southern elephant seals (Mirounga leonina), n = 10, and two fur seal species, Antarctic fur seals (Arctocephalus gazella; n = 5) and subantarctic fur seals (Arctocephalus tropicalis; n = 5), sampled between 2012 and 2017. In the whisker subsamples analyzed (n = 71), the median concentration of steroid hormones detected above the LOQ ranged from 2.0 to 273.7 pg/mg. This was the first extraction of multiple C19 and C21 steroids, including their C11-oxy metabolites, from the whiskers of mammals. Measuring hormones sequentially along the whisker lengths can contribute to our understanding of the impact of stress associated with environmental/climate changes that affect the health, survival of organisms, as well as to delineate the reproductive cycles of free-living mammals with cryptic life stages.

中文翻译：

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晶须里有什么？通过超高效能色谱-串联质谱法对哺乳动物晶须中的28种C19和C21类固醇进行高通量分析。

从自由放养的动物获得纵向内分泌学数据仍然具有挑战性。可以从非侵入性采样的生物学惰性角蛋白组织（例如羽毛，指甲，头发和胡须）中顺序提取类固醇激素。然而，关于掺入此类组织的类固醇的类型和水平的不确定性使它们在野生生物研究中的实用性复杂化。在这里，我们开发了一种新颖的，全面的方法，使用超高效能色谱-串联质谱法在一个6分钟的色谱步骤中，按时间顺序分析了沿着密封须的长度顺序沉积的14个C19和14个C21类固醇。检测限和定量限分别为0.01至2 ng / mL和0.1至10 ng / mL。对于浓度≥2ng / mL的类固醇，其准确性和精密度均在可接受的范围内。使用空白晶须基质样品评估的回收率（在200 ng / mL时平均值= 107.5％），类固醇的基质效应和工艺效率均可接受。该方法用于分析从南象海豹（Mirounga leonina）（n = 10）和两种海狗物种，南极海狗（Arctocephalus gazella; n = 5）和亚极皮下获得的成年雌须晶须中类固醇激素水平海豹（Arctocephalustropicis； n = 5），于2012年至2017年之间采样。在所分析的晶须子样本（n = 71）中，在最低定量限以上检测到的类固醇激素的中位浓度为2.0至273.7 pg / mg。这是多种C19和C21类固醇（包括其C11-氧基代谢物）的首次提取，来自哺乳动物的胡须。沿晶须长度顺序测量激素可有助于我们理解与环境/气候变化相关的压力的影响，环境/气候变化会影响生物的健康，生存，并描绘出生命周期隐秘的自由生活哺乳动物的生殖周期。