High-Resolution Gas Chromatography Retention Data as Basis for the Estimation of K_ow Values Using PCB Congeners as Secondary Standards

Abstract

We estimated KOW values that are usually derived by liquid chromatography solely from gas chromatographic (GC) data by selective correlation with PCB congeners as secondary standards. The GC method was established and validated with literature-known values obtained with other methods. Twenty-seven chlorinated diphenyl ethers (PCDE), 19 chlorinated naphthalenes (PCN), 4,4'-DDE, and three brominated diphenyl ethers (PBDE) were used for method validation. The advantages of our method are that only amounts in the nanogram range or less are needed, complex mixtures can be analyzed, KOW values of isomers can be determined, and even the exact structure of compounds does not have to be known. The quality of the KOW values obtained by the GC method mainly depends on the accuracy of the data of the compounds used as standards for the correlation. These data should be based on reliable experimental methods. Our semi-experimental approach in approximating physicochemical data relevant to the environmental distribution--vapor pressure of subcooled liquid and log KOW--can be extended to further classes of compounds because normalized GC retention data are easily available. We exemplified our approach with a bioaccumulating naturally occurring heptachlorinated 1-methyl-1',2-bipyrrole, which is highly abundant in fish from the South Atlantic among others.

Development of quantitative structure gas chromatographic relative retention time models on seven stationary phases for 209 polybrominated diphenyl ether congeners

“…QSRRs have been developed for a number of halogenated organic contaminant groups [14][15][16][17]. For PBDEs, Rayne and Ikonomou presented several predictive equations with five or seven simple parameters, including the numbers of ortho, meta, and para substituents, as well as molecular mass and calculated ionization potential and dipole moment, as independent variables [18][19][20].…”

A quantitative structure–retention relationship study for prediction of chromatographic relative retention time of chlorinated monoterpenes

“…In the last two decades QSRR have often been applied to: (1) predict retention for a new solute; (2) identify the most informative structural descriptors (regarding properties); (3) gain insight into the molecular mechanism of separation operating in a given chromatographic system; (4) evaluate complex physicochemical properties of analytes; and (5) predict relative biological activities. QSRRs have been developed for a number of halogenated organic contaminant groups (Ong and Hites 1991;Nevalainen et al 1994;Hale et al 1985;Hackenberg et al 2003). For polybrominated diphenyl ethers (PBDEs), Rayne and Ikonomou presented several predictive equations with five or seven simple parameters, including the numbers of ortho, meta, and para substituents, as well as molecular mass and calculated ionization potential and dipole moment, used as independent variables (Rayne and Ikonomou 2003).…”

Water‐Dragging Ability of Aromatic Compounds in Octanol‐Water Systems: A Quantitative Approach by Spectra Deconvolution

“…Quantitatively experimental investigations of the K ow system are generally involved with tedious experimental methods, such as isotopic 1 H NMR spectrum or Karl-Fischer ogy coupled gas chromatography (GC) and liquid chromatography (LC) have successfully estimated the K ow values for chlorinated diphenyl ethers and naphthalenes. 12 But the quality of the K ow values obtained by the GC method mainly depends on the accuracy of the data of standard compounds used for the correlation. 12 These facts make the study of K ow values for the octanol-water system complicated under these conventional techniques.…”

“…12 But the quality of the K ow values obtained by the GC method mainly depends on the accuracy of the data of standard compounds used for the correlation. 12 These facts make the study of K ow values for the octanol-water system complicated under these conventional techniques. Generally, the solute with better water-dragging ability will have a smaller Log K ow (i.e.…”

“…It is essential in the determination of the K ow value 1,4 to know the state of aggregation and the structure of the minor component in each solvent phase, and the possible effects introduced by the relationship of hydration capacity and molecular structure. However, the exact structure of the hydrate compound in the organic solvent phase 12 is unable to be elucidated by the coupled GC with LC method. Here, we use a Fouriertransform infrared (FT-IR) spectrophotometer, an ease of access instrument, coupled with a spectral deconvolution model to solve the hydrate capacity involved with complicated molecular interactions of adsorbed water (in octanol phase), partitioning aromatic solute molecules of octanolwater biphasic system, and the relationship between water-dragging behavior and K ow values.…”