Segura Pedro Alejandro, Kaplan Pearl, Yargeau Viviane
Department of Chemical Engineering, McGill University, 3610 University, Montreal, QC, H3A 2B2, Canada.
Chem Cent J. 2013 Apr 23;7(1):74. doi: 10.1186/1752-153X-7-74.
Quantitative methods for the analysis of contaminants of emerging concern (CECs) are abundant in the scientific literature. However, there are few reports on systematic methods of identification and structural identification of transformation products. For this reason, a new method based on high-resolution mass spectrometry and differential analysis was developed in order to facilitate and accelerate the process of identification and structural elucidation of transformation products CECs. This method was applied to the study of ozonation transformation products (OTPs) of the natural hormone estrone (E1).
A control compare trend experiment consisting in the comparison of a control sample to several samples having been exposed to decreasing concentrations of O3(aq) indicated that 593 peaks could be associated with OTPs. After applying various filters to remove background noise, sample contaminants and signal spikes, this data set was reduced to 16 candidate peaks. By inspection of the shape of these peaks, only two compounds OTP-276 (m/z 275.12930) and OTP-318 (m/z 317.14008) were considered as good candidates for further study. Multi-stage tandem mass spectrometry (MSn) experiments of SPE extracts of the ozonated samples of E1 and of a deuterium-labeled analogue (E1-d4) showed that OTP-276 and OTP-318 had carboxylic acid and hydroxyl functional groups, as previously reported for OTPs of other hormones. Structures for these two compounds were proposed based on their MSn spectra.
These results indicate that the method proposed is a systematic and rapid approach to study transformation products of CECs.
科学文献中有大量用于分析新兴关注污染物（CECs）的定量方法。然而，关于转化产物的系统鉴定方法和结构鉴定的报道却很少。因此，开发了一种基于高分辨率质谱和差异分析的新方法，以促进和加速CECs转化产物的鉴定和结构解析过程。该方法应用于天然激素雌酮（E1）的臭氧化转化产物（OTPs）研究。
一项对照比较趋势实验，即将对照样品与几个暴露于浓度逐渐降低的O3（水溶液）中的样品进行比较，结果表明593个峰可能与OTPs有关。在应用各种滤波器去除背景噪声、样品污染物和信号尖峰后，该数据集减少到16个候选峰。通过检查这些峰的形状，只有两种化合物OTP - 276（m/z 275.12930）和OTP - 318（m/z 317.14008）被认为是进一步研究的良好候选物。对E1臭氧化样品和氘标记类似物（E1 - d4）的固相萃取提取物进行多级串联质谱（MSn）实验表明，OTP - 276和OTP - 318具有羧酸和羟基官能团，这与之前报道的其他激素的OTPs情况相同。基于它们的MSn光谱提出了这两种化合物的结构。
这些结果表明，所提出的方法是一种系统且快速的研究CECs转化产物的方法。
