Direct analysis of bromine and iodine in dried serum spots by laser ablation inductively coupled plasma mass spectrometry.

RATIONALE: Accurate quantitative analysis of bromine and iodine in serum is an important aspect of monitoring body condition, but the volatile loss of halogen in sample pretreatment is a troublesome problem. We present a validated and flexible high-throughput method for quantification of bromine and iodine in dried serum spots (DSS) using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and an external aqueous standard calibration curve. The influence of serum matrix and laser ablation (LA) conditions on the analysis of bromine and iodine in DSS was researched systematically. METHODS: Aqueous standards without matrix matching were used for calibration to analyze bromine and iodine in serum by LA-ICP-MS. 5-µL volumes of the aqueous standard solution and serum samples in 10 times diluted concentration were deposited on the PTFE paper to form dried standard calibration spots (DSCS) and DSS, of less than 2 mm in diameter. LA was performed using a focused Nd:YAG laser beam in raster lineal scan mode. RESULTS: The limits of detection (LODs) for bromine and iodine in DSS were 0.23 and 0.03 mg L-1 , respectively. The relative standard deviation (RSD) for this method was less than 10%. The samples were also detected with matrix matching calibration by ICP-MS. The accuracy of the method was verified by statistical analysis of these results from ICP-MS and LA-ICP-MS. The accuracy is satisfactory with recoveries ranging from 81.5% to 118%. CONCLUSIONS: A novel and simple approach for high-throughput screening of bromine and iodine in DSS has been established by LA-ICP-MS. Calibration could be achieved using an aqueous standard solution instead of a matrix-matching solution. The method allowed analysis of low-volume biological samples without derivatization and decreased the risk of contamination or loss.

catena-Poly[[[aqua-copper(II)]-bis-[µ-N,N'-bis-(pyridin-4-yl)isophthalamide]-[aqua-copper(II)]-di-µ-sulfato] dimethyl-formamide disolvate].

In the title coordination polymer, {[Cu(SO4)(C18H14N4O2)(H2O)]·C3H7NO} n , the Cu(II) ion is coordinated by two N atoms of two briding N,N'-bis-(pyridin-4-yl)isophthalamide ligands, two O atoms of two bridging SO4(2-) anions and a water mol-ecule, giving a distorted CuN2O3 square-pyramidal geometry. The whole repeating mol-ecular unit is generated by inversion symmetry. This leads to the formation of a looped-chain one-dimensional coordination polymer propagating along [110]. The dimethyl-formamide (DMF) mol-ecules are linked to the chains via O-H⋯O hydrogen bonds. The chains are linked via N-H⋯O hydrogen bonds, forming two-dimensional networks parallel to (001). There are also a number of C-H⋯O inter-actions present and a parallel slipped π-π inter-action. The latter involves inversion-related pyridine rings with a centroid-centroid distance of 3.594 (2) Š[normal distance = 3.3338 (13) and slippage = 1.341 Å]. These inter-actions lead to the formation of a three-dimensional structure.

Dietary exposure risk of bisphenol S in vegetables and fruits inHenan Province / 预防医学

Objective@#To monitor the content of bisphenol S ( BPS ) in vegetables and fruits in Henan Province and evaluate the dietary exposure risk of the population, so as to provide the basis for formulating relevant food safety standards.@*Methods@#From 2018 to 2019, 276 samples of vegetables and fruits produced and sold in Henan Province were collected. BPS was determined by isotope dilution ultra performance liquid chromatography triple quadrupole tandem mass spectrometry ( UPLC-MS/MS ) , and the dietary exposure was calculated according to the dietary structure and average body weight of local residents. The risk index of BPS was calculated according to the daily tolerable intake ( TDI ) of bisphenol A ( BPA ). @*Results@#The BPS contents in vegetables and fruits were 0.006-12.600 µg/kg and 0.006-9.380 µg/kg, the medians were 0.053 µg/kg and 0.023 µg/kg, the detection rates were 78.43% and 62.60%, respectively.The detection rate and content of BPS in vegetables were higher than those in fruits ( P<0.05 ). The maximum exposure of BPS from vegetables and fruits was 5.37×10-2 µg/ ( kgbw·d ), and the exposure risk index was 1.07 × 10-3, which was acceptable. @*Conclusions@#BPS was detected from vegetables and fruits in Henan Province. The detection rate and content of BPS in vegetables were higher than those in fruits. The health risk of BPS exposed by vegetables and fruits is small.

In vitro study of the effects of Angiostrongylus cantonensis larvae extracts on apoptosis and dysfunction in the blood-brain barrier (BBB).

It has been hypothesized that blood-brain barrier (BBB) dysfunction in Angiostrongylus cantonensis infection might be due to the apoptosis of the hosts' BBB cells. Here, we evaluated this hypothesis through several methods, all based on an in vitro mouse BBB model consisting of primary culture brain microvascular endothelial cells (BMECs) and brain astrocytic cells (BACs). In the present study, a four-hour percolation and HRP permeability experiment showed that A. cantonensis larvae extracts can increase the permeability of the BBB. Apoptosis among BMECs and BACs after exposure to larvae extracts was monitored by TUNEL and annexin-V-FITC/PI double staining. A. cantonensis larvae extracts were found to induce apoptosis in both BMECs and BACs. For this reason, we concluded that the induction of apoptosis might participate in the BBB dysfunction observed during angiostrongyliasis. Improved fundamental understanding of how A. cantonensis induces apoptosis may lead to new approaches to the treatment or prevention of this parasitic disease.