Departament de Química Analítica, Universitat de València, Burjassot, Spain.
J Sep Sci. 2010 Jun;33(10):1398-404. doi: 10.1002/jssc.200900723.
A column selection valve and a 6-port 2-position injection valve were combined to implement bi-dimensional LC in a system driven by a single pump. The system was applied to the separation of linear fatty alcohol ethoxylates with 12-18 carbon atoms in the hydrocarbon moiety, previous derivatization with diphenic anhydride. Separation on the first separation dimension (C(1)) was carried out with a propyl-diol column and an acetonitrile/aqueous ammonium acetate gradient. Fatty alcohol ethoxylate hydrocarbon series (oligomers with the same number of carbon atoms in the alkyl chain but differing in the number of ethylene oxide units) were resolved without distinguishing the oligomers within the series. Selected segments of the eluate of C(1) were transferred to the second column (C(2)), where the successive oligomers within the isolated series were resolved by using either an octyl-silica or a pentafluoro-phenyl-propyl column and an acetonitrile/water gradient. Flow stopping at C(1) during system re-conditioning and elution along the second dimension did not produce any noticeable band broadening. Overlapping of the non-ethoxylated and mono-ethoxylated oligomers with other oligomers within the series was avoided by eluting the pentafluoro-phenyl-propyl column at low temperatures (3 degrees C).
采用单泵驱动，将列选择阀与六通 2 位进样阀相结合，在二维液相色谱系统中实现了分离。该系统应用于经二苯甲酮酸酐衍生化的直链脂肪醇聚氧乙烯醚（C12-18）的分离。在第一个分离维度（C1）上，采用丙二醇柱和乙腈/乙酸铵水溶液梯度洗脱进行分离。脂肪醇聚氧乙烯醚烃基系列（烷基链上碳原子数相同但氧化乙烯单元数不同的低聚物）可实现分离，而无需对该系列中的低聚物进行区分。C1 洗脱液的选定部分被转移到第二根柱（C2）上，通过采用辛基硅烷或五氟苯基丙基柱和乙腈/水梯度洗脱，可对分离出来的孤立系列中的连续低聚物进行分离。在系统重新平衡和沿第二维洗脱时，在 C1 处停止流动不会导致任何明显的带宽变宽。通过在低温（3°C）下洗脱五氟苯基丙基柱，避免了非乙氧基化和单乙氧基化低聚物与该系列中其他低聚物的重叠。
