College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 311121, China.
Key Laboratory of Organosilicon Chemistry and Material Technology, Hangzhou Normal University, Hangzhou, 311121, China.
Anal Chim Acta. 2020 Oct 9;1133:30-38. doi: 10.1016/j.aca.2020.07.046. Epub 2020 Jul 30.
Quantification of organolead compounds in environmental water is an essential task considering much higher toxicity and bioavailability of organolead species than inorganic plumbic ions. However, the speciation of ultra-trace organolead compounds at sub ng L levels is challengeable for current instruments incorporating high performance liquid chromatography with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) and even offline enrichment that offer detection limits around several to tens of ng L. In this paper, an online solid-phase extraction (SPE) coupled HPLC-ICP-MS method was developed for speciation analysis of trace lead in water. Graphene oxide bounded silica particles (GO@SiO) was utilized as the SPE adsorbent because of its superior performance over graphene bounded silica particles and commercial C packing particles. High enrichment factors (1603 for TML and 1376 for TEL) were obtained when lead species in 10 mL sample was adsorbed by 1 mM sodium dodecyl benzene sulfonate (SDBS) preconditioned GO@SiO at 10 mL min and then eluted by 5 μL of 5 mM SDBS. Because of the highly efficient preconcentration, detection limits were downscaled to be 0.018 for TML and 0.023 ng L for TEL with relative standard deviations below 5%. Additionally, the proposed method also yielded rapid separation of Pb(II), TML and TEL (8 min) by using green mobile phases (aqueous solutions of 5 mM sodium 1-pentanesulfonate at pH 2.5 with/without 4 mM tetrabutylammounium hydroxide). Upon successful application to fresh water, TML and TEL were only presented in the river water whereas Pb(II) was only existed in the tap water, along with accuracy validation by good spiked recoveries (93-106%).
考虑到有机铅物种比无机铅离子的毒性和生物利用度要高得多，因此对环境水中的有机铅化合物进行定量分析是一项至关重要的任务。然而，对于当前结合高效液相色谱与电感耦合等离子体质谱（HPLC-ICP-MS）的仪器，甚至对于提供几个到几十个纳克每升左右检测限的离线富集，痕量有机铅化合物的形态分析仍然具有挑战性。在本文中，开发了一种在线固相萃取（SPE）-高效液相色谱-电感耦合等离子体质谱联用（HPLC-ICP-MS）方法，用于水中痕量铅的形态分析。由于其优于石墨烯结合的硅胶颗粒和商用 C 包装颗粒的性能，因此将氧化石墨烯结合的硅胶颗粒（GO@SiO）用作 SPE 吸附剂。当 10 mL 样品中的铅物种被 1 mM 十二烷基苯磺酸钠（SDBS）预处理的 GO@SiO 在 10 mL/min 下吸附，然后用 5 μL 5 mM SDBS 洗脱时，可获得高的富集因子（TML 为 1603，TEL 为 1376）。由于高效的预浓缩，检测限降低到 TML 为 0.018 纳克每升，TEL 为 0.023 纳克每升，相对标准偏差低于 5%。此外，该方法还使用绿色流动相（pH 值为 2.5 的 5 mM 戊烷磺酸钠水溶液，含/不含 4 mM 四丁基氢氧化铵），快速分离 Pb(II)、TML 和 TEL（8 分钟）。将该方法成功应用于淡水后，仅在河水中检测到 TML 和 TEL，而在自来水中仅检测到 Pb(II)，加标回收率良好，验证了方法的准确性（93-106%）。
