2 research outputs found
A Novel Method for Profiling and Quantifying Short- and Medium-Chain Chlorinated Paraffins in Environmental Samples Using Comprehensive Two-Dimensional Gas Chromatography–Electron Capture Negative Ionization High-Resolution Time-of-Flight Mass Spectrometry
Chlorinated paraffins
(CPs) are complex technical mixtures containing
thousands of isomers. Analyzing CPs in environmental matrices is extremely
challenging. CPs have broad, unresolved profiles when analyzed by
one-dimensional gas chromatography (GC). Comprehensive two-dimensional
GC (GC×GC) can separate CPs with a high degree of orthogonality.
A novel method for simultaneously profiling and quantifying short-
and medium-chain CPs, using GC×GC coupled with electron capture
negative ionization high-resolution time-of-flight mass spectrometry,
was developed. The method allowed 48 CP formula congener groups to
be analyzed highly selectively in one injection through accurate mass
measurements of the [M – Cl]<sup>−</sup> ions in full
scan mode. The correlation coefficients (<i>R</i><sup>2</sup>) for the linear calibration curves for different chlorine contents
were 0.982 for short-chain CPs and 0.945 for medium-chain CPs. The
method was successfully used to determine CPs in sediment and fish
samples. By using this method, with enhanced chromatographic separation
and high mass resolution, interferences between CP congeners and other
organohalogen compounds, such as toxaphene, are minimized. New compounds,
with the formulas C<sub>9</sub>H<sub>14</sub>Cl<sub>6</sub> and C<sub>9</sub>H<sub>13</sub>Cl<sub>7</sub>, were found in sediment and biological
samples for the first time. The method was shown to be a powerful
tool for the analysis of CPs in environmental samples
Human Exposure to Short- and Medium-Chain Chlorinated Paraffins via Mothers’ Milk in Chinese Urban Population
Chlorinated paraffins (CPs) are high
production volume synthetic
chemicals, found ubiquitously in various environmental matrices. However,
little information is available on CP contamination in mothers’
milk. In this study, 1370 urban mothers’ milk samples were
collected from 12 Chinese provinces in 2007 and 16 provinces in 2011.
CP geographical distribution and congener group profiles were studied
to assess the CP levels and figure out the source of exposure in humans.
Twenty-eight pooled samples were analyzed for 48 short-chain CP (SCCP)
and medium-chain CP (MCCP) congener groups using the GC × GC-ECNI-HRTOFMS
method. The median concentrations of SCCPs were 681 and 733 ng/g lipid
in 2007 and 2011, respectively; median concentrations of MCCPs were
60.4 and 64.3 ng/g lipid in 2007 and 2011, respectively. Variations
of more than 2 orders of magnitude in CP exposure levels were found
between different provinces. The levels of CPs increased from 2007
to 2011, which indicates that CP production and use may be an important
exposure source. This is the first global comprehensive and large-scale
investigation of CPs in mothers’ milk, and it lays foundations
for improving our understanding of the metabolism of CPs in humans.
The high CP concentrations found in Chinese mothers’ milk should
raise concern about potential toxic effects in both mothers and breastfeeding
infants