Analytical Chemistry Research and Development Group (QUIANID), (LISAMEN - CCT - CONICET - Mendoza), Av. Ruiz Leal S/N Parque General San Martín, M 5502 IRA Mendoza, Argentina.
Talanta. 2011 Sep 30;85(4):2182-8. doi: 10.1016/j.talanta.2011.07.065. Epub 2011 Jul 28.
A non-chromatographic separation and preconcentration method for Se species determination based on the use of an on-line ionic liquid (IL) dispersive microextraction system coupled to electrothermal atomic absorption spectrometry (ETAAS) is proposed. Retention and separation of the IL phase was achieved with a Florisil(®)-packed microcolumn after dispersive liquid-liquid microextraction (DLLME) with tetradecyl(trihexyl)phosphonium chloride IL (CYPHOS(®) IL 101). Selenite [Se(IV)] species was selectively separated by forming Se-ammonium pyrrolidine dithiocarbamate (Se-APDC) complex followed by extraction with CYPHOS(®) IL 101. The methodology was highly selective towards Se(IV), while selenate [Se(VI)] was reduced and then indirectly determined. Several factors influencing the efficiency of the preconcentration technique, such as APDC concentration, sample volume, extractant phase volume, type of eluent, elution flow rate, etc., have been investigated in detail. The limit of detection (LOD) was 15 ng L(-1) and the relative standard deviation (RSD) for 10 replicates at 0.5 μg L(-1) Se concentration was 5.1%, calculated with peak heights. The calibration graph was linear and a correlation coefficient of 0.9993 was achieved. The method was successfully employed for Se speciation studies in garlic extracts and water samples.
提出了一种基于在线离子液体（IL）分散微萃取系统与电热原子吸收光谱法（ETAAS）联用的硒形态测定中非色谱分离和预浓缩方法。在分散液液微萃取（DLLME）后，用 Florisil（®）填充微柱实现 IL 相的保留和分离，使用十四烷基（三己基）氯化膦 IL（CYPHOS（®）IL 101）。亚硒酸盐[Se（IV）]形态通过形成硒-铵吡咯烷二硫代氨基甲酸盐（Se-APDC）络合物，然后用 CYPHOS（®）IL 101 萃取进行选择性分离。该方法对 Se（IV）具有高度选择性，而硒酸盐[Se（VI）]则被还原，然后间接测定。详细研究了影响预浓缩技术效率的多个因素，如 APDC 浓度、样品体积、萃取相体积、洗脱剂类型、洗脱流速等。检测限（LOD）为 15 ng L（-1），在 0.5 μg L（-1）Se 浓度下，10 个重复的相对标准偏差（RSD）为 5.1%，以峰高计算。校准曲线呈线性，相关系数为 0.9993。该方法成功用于大蒜提取物和水样中的硒形态研究。
