Comparison of the behavior of 13C- and deuterium-labeled polycyclic aromatic hydrocarbons in analyses by isotope dilution mass spectrometry in combination with pressurized liquid extraction

Evaluation of Behavioral Differences between Native Polycyclic Aromatic Hydrocarbons and 13C-Labeled Internal Standards during Clean-up Steps of Analysis

“…There are two possible causes of low recovery yields of spiked 13 C-PAHs in this study. One is volatilization during concentration steps and the other is irreversible adsorption of some spiked internal standards on the silica-gel cartridge.…”

“…GC 13,14 Note that the peak intensity of Per-d12 in the calibration solution, which is used as a criterion in the recovery calculation, is affected by the residue remaining in the injection liner. 14 Thus, the calibration solution was always injected after the samples in this study to obtain a constant peak intensity for Per-d12.…”

“…With respect to different behaviors of isotope-labeled PAHs relative to native PAHs, we previously reported that such differences occur during extraction steps involving pressurized-liquid extraction (PLE) even when the corresponding 13 C-labeled PAHs are used as internal standards, and they also affect the observed concentrations (by -1.4 to +0.81% for extraction at 150˚C, and by -8.5 to -1.1% for extraction at 40˚C). 13 Since differences in the behaviors of native PAHs and 13 C-labeled PAHs were more significant at 40˚C than at 150˚C, it is possible that different behaviors also occur during clean-up steps and do affect the observed concentrations. Since clean-up using silicagel in combination with PLE is commonly used for the determination of PAHs in solid samples, the effect on the observed concentrations should be evaluated using this procedure.…”

Evaluation of minimal 13C-labelling for stable isotope dilution in organic analysis

“…3 However, when multiple labelling of a molecule is performed, differences in its physicochemical properties in comparison with the natural abundance compound have been observed. [8][9][10][11] This is particularly true with deuterated compounds, because of slightly different hydrogen bonding capabilities, resulting in slightly different extraction and derivatisation yields from those observed for the natural abundance compounds. 8 Also, undesired changes in retention times both in GC 9 and LC 10 separations have been reported.…”

“…[8][9][10][11] This is particularly true with deuterated compounds, because of slightly different hydrogen bonding capabilities, resulting in slightly different extraction and derivatisation yields from those observed for the natural abundance compounds. 8 Also, undesired changes in retention times both in GC 9 and LC 10 separations have been reported. Most of these isotopic effects are small and can be compensated for when the calibration graph is constructed following the analytical procedure used for the samples.…”