摘要
本文在 Martire 等人以平均场晶格模型处理超临界流体色谱(SFC)保留值方法的基础上,提出修正函数的假设,结合实验数据确定了修正函数的具体表达式为△′=(0.01605+0.02387n_■)ρ~3_■/T,-(0.01382+0.02055n_■)ρ~4_■/T_■。经过修正后的保留值方程可在较大密度范围内(ρ_■:0.705～1.632)定量描述正构烷烃在非极性柱上,超临界流体 CO_2中的保留值变化规律。
The retention behaviours of normal hydrocarbons(from n-c^(0_s) to n-c^(0_(32)))on a cross-linked polymethylsiloxane capillary column(13m×90μm I.D.)with superitical fluid carbon dioxide as mobile phase have been investigated.The reduced density(ρ_r)and redu- ced temperature(T_t)under the investigation are in the range from 0.705 to 1.632 and 1.079 to 1.293,respectively.The Martire and Boehm retention equation,which was derived from the mean-field lattics model of statistical thermodynamics,was modified by conside- ring the effect of interaction between supercritical fluid and stationary phase on solute re- tention.Two additional assumptions have been made in the modification,they are θ_d(s)=θ~od(s)+aαρ_s (1) Where θ_d(s)is the fraction of stationary molecule d in stationary phase s,μ~0d(s)is the value of θ_d(s)when ρ,approaches zero.a is constant. ε_(ad)/ε_(bb)and ε_(dd)/ε_(bb) are only the ruction of ρ_r.Where ε_(ij)is the energy of interaction between the fregmonts of i and j molecules.The ln k under this conditions can be expressed as follows ln k=ln k^0+F’(T_r,ρ_r)+(Aρ^(3_r)+Bρ_(4_z)/T_r (2) Where ln k^0 is the solute retention value ln k when ρ_r approaches zero,F’(T_r,ρ_z)is the value of ln k contributed by mobile phase,A,B are constant,respectively.The imp- roved equation(2)is in good agreement with the experiment dataobtained.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
1991年第10期1122-1127,共6页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金资助项目
关键词
烃类
保留值
超临界流体
SFC
Retention behaviour of chromatography
Supercritical fluid chromatography
