Yun Tao

Exposure to organochlorine pesticides and non-Hodgkin lymphoma: a meta-analysis of observational studies

Growing evidence indicates that exposure to organochlorine pesticides (OCPs) could increase non-Hodgkin lymphoma (NHL) risk. However, results from epidemiological studies investigating this association remain controversial. We thus conducted a meta-analysis to quantitatively evaluate the association between OCP exposure and NHL risk. Relevant publications were searched in PubMed, Web of Science, and Embase and identified according to the inclusion criteria. Thirteen studies (6 nested case-control, 1 case-cohort, and 6 case-control) were selected for this meta-analysis. We used odds ratios (ORs) with 95% confidence intervals (CIs) to estimate the relationship between OCPs exposure and NHL risk. The summary OR for included studies was 1.40 (95% CI 1.27 to 1.56). No overall significant heterogeneity in the OR was observed (Ph = 0.253, I2 = 12.6%). Furthermore, OR estimates in subgroup analyses were discussed, and strong associations were observed for dichlorodiphenyldichloroethylene (DDE, OR = 1.38, 95% CI 1.14 to 1.66), hexachlorocyclohexane (HCH, OR = 1.42, 95% CI 1.08 to 1.87), chlordane (OR = 1.93, 95% CI 1.51 to 2.48), and hexachlorobenzene (HCB, OR = 1.54, 95% CI 1.20 to 1.99). This meta-analysis had suggested that total OCPs of interest was significantly positively associated with NHL risk.

Occurrence investigation of perfluorinated compounds in surface water from East Lake (Wuhan, China) upon rapid and selective magnetic solid-phase extraction

Using a novel magnetic nanocomposite as adsorbent, a convenient and effective magnetic solid-phase extraction (MSPE) procedure was established for selective separation and concentration of nine perfluorinated compounds (PFCs) in surface water sample. Then an ultra high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) system was employed for detection of PFCs. Good linearity of the developed analytical method was in the range of 0.5–100 ng L−1 with R2 > 0.9917, and the limits of detection (LODs) ranged from 0.029 to 0.099 ng L−1. At three fortified concentrations of 0.5, 5 and 50 ng L−1, the spiked recoveries of PFCs were in the range of 90.05–106.67% with RSDs < 12.62% (n = 3). The proposed analytical method was applied for determination of PFCs in surface water from East Lake (Wuhan, China). The total concentrations of nine PFCs ranged from 30.12 to 125.35 ng L−1, with perfluorooctane sulfonate and perfluoroctanoic acid as the most prevalent PFCs, and the greatest concentrations of PFCs were observed in Niuchao lakelet. The concentrations of the PFCs (C ≥ 11) were mostly less than the limits of quantification (LOQs), attributed to the possibility that the more hydrophobic long-chain PFCs are potential to accumulate in sediment and aquatic biota.

Exposure to organophosphate flame retardants of hotel room attendants in Wuhan City, China

Indoor environments provide sources of exposure to organophosphate flame retardants (PFRs), which are artificially synthesized fire-protecting agents used as additives in interior products. As public spaces, hotels are required to meet stricter fire-precaution criteria. As such, room attendants may be exposed to higher levels of PFRs. Our goal was to characterize the exposure of hotel room attendants to PFRs by measuring metabolites in their urine and the corresponding parent PFRs in dust and hand-wipes collected from 27 hotels located in Wuhan City, China. The exposure of the attendants was found to be omnipresent: urinary metabolites of PFRs, such as DPHP (diphenyl phosphate), BDCIPP (bis(1,3-dichloro-2-propyl) phosphate), and DoCP (di-o-cresyl phosphate) & DpCP (di-p-cresyl phosphate) were detected with high frequency (87%, 79% and 87%, respectively). We observed that metabolites in post-shift urine were consistently present at higher levels than those in the first morning voids (p < 0.05 for BDCIPP and DPHP). Regarding external exposure, 10 PFRs were determined in both dust samples and hand-wipes, with TCIPP (tris(2-chloroisopropyl) phosphate) being the most abundant compound in both matrices. The levels of PFRs in hand-wipes and dust samples were not correlated. PFRs in dust and their corresponding urinary metabolites were not significantly correlated, while a moderate significant correlation of TDCIPP (tris(1,3-dichloro-2-propyl) phosphate) in hand-wipes and its urinary metabolite, BDCIPP, was observed in both morning void samples (p = 0.01) and post-shift urine (p = 0.002). Moreover, we found that participants from high-rise buildings (defined as > 7 stories) had significantly higher BDCIPP and DPHP concentrations than those from low-rise buildings. A possible reason is that high-rise buildings may use high-grade fireproof building materials to meet stricter fire restrictions. Overall, these results indicate that PFRs exposure in hotels is a contributor to the personal exposure of hotel room attendants.

Fabrication of a Selective and Sensitive Sensor Based on Molecularly Imprinted Polymer/Acetylene Black for the Determination of Azithromycin in Pharmaceuticals and Biological Samples

A new selective and sensitive sensor based on molecularly imprinted polymer/acetylene black (MIP/AB) was developed for the determination of azithromycin (AZM) in pharmaceuticals and biological samples. The MIP of AZM was synthesized by precipitation polymerization. MIP and AB were then respectively introduced as selective and sensitive elements for the preparation of MIP/AB-modified carbon paste (MIP/ABP) electrode. The performance of the obtained sensor was estimated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. Compared with non-molecularly imprinted polymer (NIP) electrodes, NIP/ABP electrodes, and MIP-modified carbon paste electrodes, MIP/ABP electrode exhibited excellent current response toward AZM. The prepared sensor also exhibited good selectivity for AZM in comparison with structurally similar compounds. The effect of electrode composition, extraction parameters, and electrolyte conditions on the current response of the sensor was investigated. Under the optimized conditions, the prepared sensor showed two dynamic linear ranges of 1.0 × 10−7 mol L−1 to 2.0 × 10−6 mol L−1 and 2.0 × 10−6 mol L−1 to 2.0 × 10−5 mol L−1, with a limit of detection of 1.1 × 10−8 mol L−1. These predominant properties ensured that the sensor exhibits excellent reliability for detecting AZM in pharmaceuticals and biological fluids without the assistance of any separation techniques. The results were validated by the high-performance liquid chromatography–tandem mass spectrometry method.

Bioaccumulation of tetrabromobisphenol A in a laboratory-based fish–water system based on selective magnetic molecularly imprinted solid-phase extraction

Recently, magnetic solid-phase extraction (MSPE) using magnetic molecularly imprinted polymers (MMIPs), which is a simple process with excellent selectivity, has attracted much attention for the determination of environmental pollutants. In this study, MMIPs were used as an adsorbent to establish a selective MSPE method coupled with high-performance liquid chromatography using ultraviolet detection (HPLC-UV) for the determination of tetrabromobisphenol A (TBBPA) levels in water and fish samples. The samples were collected from a laboratory-based fish-water system after 0, 2, 5, 8, 11, 20, 30, and 50 days. We found that the concentrations of TBBPA in the sample group spiked with TBBPA decreased in the water samples over time and increased in the fish samples from 2 to 30 days, then finally decreased. The calculated bioconcentration factor (BCF) increased over time, reaching 33.98 L/kg after 50 days exposure to TBBPA. Linear and exponential kinetic models were applied to fit the correlation between BCF and exposure time, and the constant of the time-dependent BCF (Ku) ranged from 0.0364 to 1.5250 L/kg per day with a corresponding R2 of 0.6786 to 0.9985. Simplified mathematical models to evaluate the transfer characteristics of TBBPA in a laboratory-based fish-water system have been developed.

Rapid determination of X-ray contrast agent iomeprol in human plasma by on-line solid-phase extraction coupled with phase optimized liquid chromatography.

Phase optimized liquid chromatography (POPLC) allows for the optimized combination of column segments of any length and stationary phases with different functionalities. In this study, a simple and rapid method using POPLC coupled with on-line solid-phase extraction (SPE) for the analysis of X-ray contrast media agent iomeprol (IOM) in human plasma was developed. Because the phenyl (PH) stationary phase has strong hydrophobic and π-π interactions with IOM and iopromide (IOP, internal standard), the best separation efficiency was achieved with a 250mm×3mm homogenous PH POPLC-column. Different kinds of on-line SPE sorbents were studied, including restricted access material-alkyl diol silica (ADS), LiChrolut EN with excellent absorption capacity and hydrophilic-lipophilic-balanced Oasis HLB. The most efficient on-line sample clean-up was carried out using a fast-flow on-line purification approach with an Oasis HLB pre-column ((20mm×2mm, 30μm). This pre-column showed excellent durability and reproducibility. At least 400 samples could be analyzed with one pre-column. Each plasma sample was directly injected and analyzed within 15min. The calibration curves were linear in the range of 10-1000μg/mL. The limit of quantitation was 2.26μg/mL. The inter-day precision of this method was excellent and less than 1.44%, and the intra-day precision was less than 4.44%. The inter-day and intra-day accuracy ranged from 94.33% to 104.36% and 94.60% to 101.71%, respectively. This validated method is expected to be useful in the analysis of human plasma samples for glomerular filtration rate (GFR) measurements and assessment of kidney function.