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Effect of sample diluent with different ratios of water in supercritical fluid chromatography

Rui, Yu LU (2018) KEMR36 20181
Department of Chemistry
Abstract
Water is not a popular solvent for SFC because it usually causes peak distortion. In a previous study in the lab it was shown that a water/organic solvent ratio of 9:1 in sample diluent actually produced sharper peak shape compared with the ratio of 1:9. The aim of the current study is thus to do a systematic study of the effect of water in the sample diluent on the retention behaviors of the analytes and their peak shapes. Seven compounds with different physico-chemical properties were separated on eight SFC columns using sample diluents with different ratios of water in acetonitrile. Three injection volumes were tested at each ratio of water to organic solvent. The obtained results showed that the water effects on analyte retention and... (More)
Water is not a popular solvent for SFC because it usually causes peak distortion. In a previous study in the lab it was shown that a water/organic solvent ratio of 9:1 in sample diluent actually produced sharper peak shape compared with the ratio of 1:9. The aim of the current study is thus to do a systematic study of the effect of water in the sample diluent on the retention behaviors of the analytes and their peak shapes. Seven compounds with different physico-chemical properties were separated on eight SFC columns using sample diluents with different ratios of water in acetonitrile. Three injection volumes were tested at each ratio of water to organic solvent. The obtained results showed that the water effects on analyte retention and peak shape were compound and column dependent. As a conclusion, water in the sample solvent is quite compatible with a Diol column but very unfavourable with an HSS C18 SB column. Compared with the commonly utilized sample diluent, this observation suggests that the usage of high amount of water may favour the analysis of certain compound types, and this may lead to a wider application of SFC to analyse polar and ionizable compounds which are not soluble in conventional SFC sample diluents. (Less)
Popular Abstract
Supercritical fluid chromatography is a very environment-friendly analytical technique since it utilizes mainly carbon dioxide during sample analysis. However, in the real application of this technique, the samples being analyzed usually need to be dissolved in organic solvent, which leads to a difficulty of analyzing polar and ionizable compounds due to the poor solubility of the analytes in the sample diluent.
Water is not considered as a good solvent in supercritical fluid chromatography because the usage of water in the sample diluent usually causes peak distortion. However, in one of our previous works, it had been observed that water used in the sample diluent had helped the formation of nicer peak. As a result, this current study... (More)
Supercritical fluid chromatography is a very environment-friendly analytical technique since it utilizes mainly carbon dioxide during sample analysis. However, in the real application of this technique, the samples being analyzed usually need to be dissolved in organic solvent, which leads to a difficulty of analyzing polar and ionizable compounds due to the poor solubility of the analytes in the sample diluent.
Water is not considered as a good solvent in supercritical fluid chromatography because the usage of water in the sample diluent usually causes peak distortion. However, in one of our previous works, it had been observed that water used in the sample diluent had helped the formation of nicer peak. As a result, this current study focused on a systematic study regarding the effect of water in sample diluent on the performance of supercritical fluid chromatography. Seven analytes were analyzed on four different types of columns, and sample diluent containing four different ratios of water in a polar organic solvent were tested. The results showed, similar as what our previous work had observed, water facilitated the formation of nicer peaks, and this effect was column and analyte dependent. The hypothesis is that the water in the sample diluent may induce a water layer inside the Diol and Silica columns with polar stationary phases, which favored the analysis of compounds with larger polar surface areas (sulfanilamide and cortisone). In conclusion, using water in sample diluent is not always bad but it could be applied to improve the performance of supercritical fluid chromatography on certain cases. (Less)
Please use this url to cite or link to this publication:
author
Rui, Yu LU
supervisor
organization
course
KEMR36 20181
year
type
H2 - Master's Degree (Two Years)
subject
keywords
peak shape, retention, sample solvent effect, supercritical fluid chromatography, analytical chemistry, analytisk kemi
language
English
id
8955361
date added to LUP
2018-09-25 11:21:15
date last changed
2018-09-25 11:21:15
@misc{8955361,
  abstract     = {{Water is not a popular solvent for SFC because it usually causes peak distortion. In a previous study in the lab it was shown that a water/organic solvent ratio of 9:1 in sample diluent actually produced sharper peak shape compared with the ratio of 1:9. The aim of the current study is thus to do a systematic study of the effect of water in the sample diluent on the retention behaviors of the analytes and their peak shapes. Seven compounds with different physico-chemical properties were separated on eight SFC columns using sample diluents with different ratios of water in acetonitrile. Three injection volumes were tested at each ratio of water to organic solvent. The obtained results showed that the water effects on analyte retention and peak shape were compound and column dependent. As a conclusion, water in the sample solvent is quite compatible with a Diol column but very unfavourable with an HSS C18 SB column. Compared with the commonly utilized sample diluent, this observation suggests that the usage of high amount of water may favour the analysis of certain compound types, and this may lead to a wider application of SFC to analyse polar and ionizable compounds which are not soluble in conventional SFC sample diluents.}},
  author       = {{Rui, Yu}},
  language     = {{eng}},
  note         = {{Student Paper}},
  title        = {{Effect of sample diluent with different ratios of water in supercritical fluid chromatography}},
  year         = {{2018}},
}