Congener-Specific Partition Properties of Chlorinated Paraffins Evaluated with COSMOtherm and Gas Chromatographic Retention Indices
2020
Chlorinated Paraffins (CPs) are high
volume production chemicals and have been found in various organisms including
humans and in environmental samples from remote regions. It is thus of great importance
to understand the physical-chemical properties of CPs. In this study, gas
chromatographic (GC) retention indexes (RIs) of 26 CP congeners were measured
on various polar and nonpolar columns to investigate the relationships between
the molecular structure and the partition properties. Retention measurements
show that analytical standards of individual CPs often contain several
stereoisomers. RI values show that chlorination pattern have a large influence
on the polarity of CPs. Single Cl substitutions (-CHCl-, -CH2Cl)
generally increase polarity of CPs. However, many consecutive -CHCl- units
(e.g., 1,2,3,4,5,6-C11Cl6) increase polarity less than
expected from the total number of -CHCl- units. Polyparameter linear free
energy relationship descriptors show that polarity difference between CP
congeners can be explained by the H-bond donating properties of CPs. RI values
of CP congeners were predicted using the quantum chemically based prediction
tool COSMOthermX. Predicted RI values correlate well with the experimental
data (R2, 0.975–0.995), indicating that COSMOthermX can be
used to accurately predict the retention of CP congeners on GC columns.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
0
References
1
Citations
NaN
KQI