离子液体为背景电解质的毛细管电泳-间接紫外检测法同时测定葡萄酒中无机阴离子和阳离子

以离子液体1-乙基-3-甲基咪唑对甲苯磺酸盐（EMIm]TS）为背景电解质，采用双端进样方式，实现了毛细管电泳-间接紫外检测法同时分析测定葡萄酒中无机阳离子（K⁺、Ca²⁺、Na⁺、Mg²⁺和Li⁺）和阴离子（Cl^-、SO₄^2-和ClO₃^-）。EMIm]TS作为电泳缓冲溶液的同时，其阳离子和阴离子分别作为样品中阳离子和阴离子组分的间接紫外检测的背景电解质。在最佳分析条件下，可在6.5 min内完成8种无机离子的同时分离检测，其线性范围为0.005~0.7 g/L，相关系数为0.963~0.995，检出限（S/N=3）为1.2~12.5 mg/L。该方法成功测定了3种不同品牌的市售葡萄酒中8种无机离子。在3个加标水平下，8种无机离子的回收率为90.1%~110.5%，相对标准偏差（RSD）≤ 4.8%。结果表明，该方法可应用于葡萄酒中无机阴、阳离子的同时分离检测，且方法简单、快速且结果可靠。

Simultaneous determination of inorganic anions and cations in wine by capillary electrophoresis-indirect ultraviolet detection with ionic liquid as background electrolyte

A novel method was developed for the simultaneous determination of inorganic anions (Cl^-, SO₄^2- and ClO₃^-) and cations (K⁺, Ca²⁺, Na⁺, Mg²⁺ and Li⁺) in wine by capillary electrophoresis-indirect ultraviolet detection (CE-UV) with dual-opposite end injection using 1-ethyl-3-methylimidazolium p-toluenesulfonate (EMIm]TS) as the background electrolyte.EMIm]TS acted as the running electrolyte and probe, generating the background signals for cations and anions under indirect UV light, consequently simplifying the electrophoretic medium. Under the optimal experimental conditions, baseline separation was achieved for the eight inorganic ions within 6.5 min. The linear ranges of the eight inorganic ions were 0.005-0.7 g/L, with correlation coefficients (R²) of 0.963-0.995. The limits of detection (LODs) were between 1.2 and 12.5 mg/L at a signal-to-noise ratio of 3 (S/N=3). Eight inorganic ions were detected in three different brands of wines obtained from supermarket. Good recoveries of 90.1%-110.5% at three spiked levels (0.05, 0.2 and 0.4 g/L) were achieved with a low relative standard deviations (RSDs) (n=5) of 1.1%-4.8%. The proposed method is robust and reliable for the sensitive and rapid analysis of the inorganic anions and cations, and it has potential in evaluating the quality of wine.