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This review article forms a guideline for LIBS contribution in coal analysis, encompassing fundamental aspects, operation modes, data processing, and analytical results. LIBS applications related to coal utilization are also highlighted (fly ash analysis and combustion monitoring).

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Multiple studies have demonstrated the occurrences of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in environmental matrixes, but human internal exposure to them has been studied rarely. Mass fractions and congener group patterns of SCCPs and MCCPs in paired maternal and cord serum were studied for the first time to investigate the placental transport mechanism and prenatal exposure risks of CPs. Samples were collected in Beijing, China, and analyzed using two-dimensional gas chromatography coupled to time-of-flight mass spectrometry. SCCP and MCCP mass fractions in maternal serum were 21.7-373 and 3.76-31.8 ng/g ww, respectively. They were 8.51-107 and 1.33-12.9 ng/g ww, respectively, in cord serum. Significant positive correlation between SCCP and MCCP levels in maternal serum was found ( p < 0.01), suggesting SCCPs and MCCPs may undergo similar accumulation, transfer, and transformation pathways. The predominant congener groups for SCCP and MCCP in maternal serum were CCl and CCl. The homologue profiles of CPs in cord serum were similar but with varied contribution percentage compared with those in maternal serum. By calculating and comparing cord-maternal serum ratios for each individual congener group, passive diffusion was recognized to be the possible placental transport form. The relationships between CP and thyroid hormone concentrations (THs) indicated that exposure to CPs might affect circulating TSHs. C-CPs were also detected, improving our understanding of CPs in human serum.

The atmosphere is an important (1) pathway by which mercury (Hg) is transported around the globe and (2) source of Hg to ecosystems. Thus, understanding Hg atmospheric chemistry is critical for understanding the biogeochemical cycle and impacts to human and ecosystem health. Work over the past 13 years has demonstrated that the standard instrument used to measure atmospheric Hg does not accurately quantify gaseous oxidized mercury (GOM) or particulate bound mercury (PBM). This study focused on comparing four methods for quantifying atmospheric Hg and identifying Hg­(II) compounds. Data from two automated systems, the Tekran 2537/1130 system and the University of Nevada, Reno-Dual Channel System (DCS), were compared with two University of Nevada, Reno-Reactive Mercury Active Systems (RMAS 2.0). One RMAS 2.0 included cation exchange membranes (CEMs) and nylon membranes, and the second included a polytetrafluoroethylene (PTFE) membrane upstream of the CEM and nylon membranes. The Tekran system and the DCS underestimated GOM concentrations with respect to that measured using the RMAS 2.0. The RMAS 2.0 with the upstream PTFE provided a means of distinguishing GOM and PBM. Thermal desorption of nylon membrane data identified a variety of GOM and PBM compounds present.

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