The aim of the present study is to determine four anionic alkyl sulfate (AS) surfactants with different alkyl chains, namely, C8, C10, C12, and C14, in wastewater by CE with capacitively coupled contactless conductivity detection (CE‐C⁴D). The conditions effective for the separation of the four AS surfactants were systematically optimized and found to be in a Tris‐His (50 mM/20 mM) BGE solution at a pH of 8.95, using a separation voltage of +15 kV, hydrodynamic injection by siphoning using a 20 cm injection height and an injection time of 20 s. The LODs for C8, C10, C12, and C14 were 2.58, 2.30, 2.08, and 3.16 mg/L, respectively. The conditions used to achieve the simultaneous adsorption and preconcentration of the AS surfactants using Al₂O₃ beads were pH of 3 and 0.1 mM NaCl. The adsorption efficiencies were found to be 45.6, 50.8, 81.7, and 99.9%, while the desorption efficiencies reached 66.1, 70.4, 83.9, and 100.0% for C8, C10, C12, and C14, respectively. The concentrations of the AS surfactants in wastewater samples were quantified by CE‐C⁴D after preconcentration by simultaneous adsorption using Al₂O₃ beads. The results obtained from the proposed method were consistent with those obtained by HPLC‐MS/MS, with a deviation of less than 15%. Our results indicate that the CE‐C⁴D performed after preconcentration by an adsorption technique using Al₂O₃ beads is a new, inexpensive, and suitable method for quantifying AS surfactants in wastewater samples.

中文翻译：

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氧化铝珠同时吸附预浓缩后毛细管电泳结合非接触式电导检测分离测定废水中的烷基硫酸盐表面活性剂

本研究的目的是通过 CE 和电容耦合非接触式电导检测 (CE-C ⁴ D)测定废水中具有不同烷基链的四种阴离子烷基硫酸盐 (AS) 表面活性剂，即 C8、C10、C12 和 C14。. 对四种 AS 表面活性剂的有效分离条件进行了系统优化，发现在 pH 为 8.95 的 Tris-His (50 mM/20 mM) BGE 溶液中，使用 +15 kV 的分离电压，流体动力学注入使用 20 cm 注射高度和 20 s 注射时间进行虹吸。C8、C10、C12 和 C14 的 LOD 分别为 2.58、2.30、2.08 和 3.16 mg/L。使用 Al ₂ O ₃同时吸附和预浓缩 AS 表面活性剂的条件珠的 pH 值为 3 和 0.1 mM NaCl。发现吸附效率分别为 45.6、50.8、81.7 和 99.9%，而 C8、C10、C12 和 C14 的解吸效率分别达到 66.1、70.4、83.9 和 100.0%。废水样品中 AS 表面活性剂的浓度在使用 Al ₂ O ₃珠同时吸附进行预浓缩后通过 CE-C ⁴ D进行定量。所提方法所得结果与 HPLC-MS/MS 所得结果一致，偏差小于 15%。我们的结果表明 CE-C ⁴ D 在通过使用 Al ₂ O ₃的吸附技术进行预浓缩后进行 微珠是一种新的、廉价的、适用于量化废水样品中 AS 表面活性剂的方法。