英语翻译The order in which components of a mixture are eluted from a column is related to their relative polarty.Thus with a mixture of two components of differing polarity,e.g.a hydrocarbon and a ketone,separation is achieved because the more po

英语翻译The order in which components of a mixture are eluted from a column is related to their relative polarty.Thus with a mixture of two components of differing polarity,e.g.a hydrocarbon and a ketone,separation is achieved because the more po
英语翻译
The order in which components of a mixture are eluted from a column is related to their relative polarty.Thus with a mixture of two components of differing polarity,e.g.a hydrocarbon and a ketone,separation is achieved because the more polar ketone is adsorbed more strongly on the adsorbent and hence the hydrocarbon may be eluted with a relatively non-polar solvent; the ketone is then eluted by changing to a more polar solvent.The ease of elution of the adsorbate may be broadly in the following order:
Saturated hydrocarbons > alkenes,alkynes,aromatic hydrocarbons >esters,aldehydes and ketones > amines,alcohols,thiols > phenols,carboxylic acids.
In a comprehensive study of a mixture having unknown chromatographic characteristics it is frequently desirable to be initially guided in the selection of adsorbents and solvents from information obtained by t.1.c.analysis using alumina or silica gel on microscope slides.Only if these prove unsatisfactory
would recourse be made to the other adsorbents.
It should be noted that the resolution obtained on a t.1.c.plate is rather better than would be obtained on a conventional adsorption column (see however other column techniques below) and hence further trials should be made with the various activity grades and with controlled solvent composition changes before the bulk of material is submitted to this type of separation.It is in these trials that careful attention to the chromatographic profile obtained from suitable analysis of the eluate fractions,and to the total recovery of material from the column,is so important.

英语翻译The order in which components of a mixture are eluted from a column is related to their relative polarty.Thus with a mixture of two components of differing polarity,e.g.a hydrocarbon and a ketone,separation is achieved because the more po
在混合而成的部件都是由一栏eluted与其相关的改变.这样的两部分组成,例如一不同的极性和酮、分离是因为更极地酮吸附更强烈的吸附剂,因此碳氢化合物可以通过相对eluted无极溶剂、酮是通过改变,然后eluted更极性溶剂.轻松的教材,可广泛应用于”下列顺序:饱和烃>烯烃、alkynes、芳烃>酯、醛、酮>铵、醇根、巯基化合物>的酚类、羧酸.
在综合研究的特点是有不为人知的混合物通常是可取析最初将引导选择差异、耐溶剂性分析的基础上,从信息t.1.c.用氧化铝或硅胶在显微镜下幻灯片.只有当这些证明不令人满意 将追索权的其他重要途径.值得注意的是,这项决议得到一个t.1.c.板将会得到比传统吸附塔(见下面),然而其他列技术的进一步的试验,因此应该拥有的各种活动和控制职系和溶剂组成变化之前提交的资料是这种类型的分离.它是在这些试验中,注意色谱剖面的分析得到合适的分数,ⅰ的总回收率从材料的专栏,也是很重要的.