场流分级的机内浓缩和再进样方法

<正> 除制备色谱外,一般色谱和场流分级的进样量都是很小的,而溶质层在经过色谱柱或场流分级柱槽后由于分离以及加宽效应浓度又要大大降低,因此,所得级分中溶质的含量极少。如需把所得级分做再进样,则必须在同一条件下重复收集同一集分,经浓缩后再进

AN IN-LINE SAMPLE CONCENTRATION AND REINJECTION METHOD FOR FIELD-FLOW FRACTIONATION

One of the advantages for field-flow fractionation is that the sample fractions obtained from one or several runs can be concentrated and reinjected in-line. Procedure of this method is simple and the trouble caused by impurities contained in carrier solvent can be avoided. This technique can be used to study the band broadening effect caused by the system or to recycle a particular fraction of polymers/particles with broad molecular weight/particle size distribution. The approach for carrying out this concentration and reinjection procedure is shown in detail. Experiment for thermal field-flow fractionation is described by using polystyrene with molecular weight 20.6×10⁶,but the principle is unversal for other kind of FFF subtechniques.