ROLE OF DISSOLVED-GASES IN HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY
ROLE OF DISSOLVED-GASES IN HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY
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DOI：
10.1016/s0021-9673(00)89973-2
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发表时间：
1978-01-01
期刊：
影响因子：
--
通讯作者：
HONGANEN, R
中科院分区：
文献类型：
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作者：
BAKALYAR, SR;BRADLEY, MPT;HONGANEN, R
溶解气体通常作为高效液相色谱中移动的相的组分存在。每种气体都有其独特的性质，并以不同的方式影响色谱。实验探索了在纯溶剂和混合溶剂中的溶解度，并与文献中已有的数据进行了比较。发现二元溶剂体系中的非线性溶解度特性解释了当空气饱和溶剂在色谱仪中混合时观察到的大量气体的逸出。在一个泵，低压混合梯度架构中的脱气要求与传统的两个泵，高压混合systems.Dissolved氧影响探测器的性能在几个方面进行了比较。它与许多溶剂形成紫外光吸收复合物。因此，氧浓度的变化导致UV检测器漂移。这种效应的大小随不同的溶剂而显著变化，并且在低于260 nm的波长下特别明显。溶解氧会猝灭溶剂和溶质的荧光。因此，荧光检测器漂移和响应度取决于氧浓度。最大的荧光灵敏度只能通过脱氧的移动的相来实现。由于这些事实，分析精度要求仔细控制气体浓度。各种控制技术进行了讨论;加热，煮沸，真空，超声波和气体喷射。介绍了一种新的氦气除气方法，它消除了气泡的形成，并使所有其它气体的水平保持在零浓度。
Dissolved gases are usually present as components of the mobile phase in high-performance liquid chromatography. Each gas has its unique properties and affects the chromatographic in different ways.the solubility in pure and mixed solvents is explored experimentally and compared with data already in the literature. it is found that the non-linear solubility characteristics in binary solvent systems account for the observed evolution of large quantities of gas when air-saturated solvents are mixed in chromatographs. The degassing requirements in one-pump, low-pressure-mixing gradient architectures are compared with those of conventional two-pump, high-pressure-mixing systems.Dissolved oxygen affects detector performance in several ways. It forms a UV light-absorbing complex with many solvents. Changes in oxygen concentration therefore cause UV detector drift. The magnitude of this effect varies markedly with different solvents, and is particularly pronounced at wavelengths below 260 nm. Dissolved oxygen quenches fluorescence of both solvents and solutes. As a consequence, fluorescence detector drift and responsivity depend on oxygen concentrations. Maximum fluorescence sensitivity can only be achieved with deoxygenated mobile phases.Because of these facts, analytical precision requires that gas concentrations be carefully controlled. The various control techniques are discussed; heating, boiling, vacuum, ultrasonics and gas sparging. A new method of helium degassing is described which eliminates bubble formation and maintains the level of all other gases at zero concentration.