School of Environment and Energy, South China University of Technology, Guangzhou, 510006, Guangdong, China.
Key Lab Pollution Control & Ecosystem Restoration in Industry Cluster, Ministry of Education, Guangzhou, 510006, Guangdong, China.
Environ Sci Pollut Res Int. 2022 Apr;29(17):24589-24598. doi: 10.1007/s11356-021-17377-7. Epub 2021 Nov 25.
It is important to keep natural estrogen conjugates (C-NEs) intact in aqueous environmental sample before sample preparation; otherwise, this may influence the accurate determination of NEs. Therefore, this work thoroughly investigated the stability of C-NEs in three different aqueous environmental samples under four different storage conditions, room temperature, low temperature of 4 °C, low pH of 3, and addition of HgCl at 2 g/L. Results showed that C-NEs in aqueous sample were easily deconjugated under low temperature of 4 °C, which has been widely used in sample collection and storage. Both the low pH of 3 and addition of HgCl at 2 g/L under room temperature could keep C-NEs intact in domestic wastewaters and river water within 36 h, but the latter could keep C-NEs stable longer. This work is the first to show that low pH of 3 alone could keep C-NEs intact, which suggested that the combined condition at low temperature of 4 °C that has been widely used could be omitted. Meanwhile, compared to pH adjustment, addition of 2 g/L HgCl into aqueous sample is more convenient and practical for 24-h composite sampling, which may be widely applied.
在进行样品制备之前，保持水相环境样品中天然雌激素轭合物（C-NEs）的完整非常重要；否则，这可能会影响 NEs 的准确测定。因此，本工作彻底研究了 C-NEs 在四种不同储存条件下（室温、4°C 低温、pH3 的低酸度和 2g/L 的 HgCl 添加）在三种不同水相环境样品中的稳定性。结果表明，C-NEs 在广泛用于样品采集和储存的 4°C 低温下容易去轭合。在室温下，pH3 的低酸度和 2g/L 的 HgCl 添加均能使生活污水和河水中原位的 C-NEs 在 36 小时内保持完整，但后者能使 C-NEs 更稳定。这是首次表明单独的低 pH3 能使 C-NEs 保持完整，这表明已广泛使用的低温 4°C 联合条件可以省略。同时，与 pH 值调整相比，将 2g/L 的 HgCl 添加到水样中对于 24 小时复合采样更方便实用，可能得到广泛应用。
