Association between mixed metal exposure and stroke risk in Shanxi Province: a case-control study.

BACKGROUND: Stroke is the second leading cause of death for all human beings and poses a serious threat to human health. Environmental exposure to a mixture of metals may be associated with the occurrence and development of stroke, but the evidence in the Chinese population is not yet conclusive. OBJECTIVES: This study evaluated the association between stroke risk and 13 metals METHODS: Metal concentrations in whole blood samples from 100 stroke cases and 100 controls were measured by ICP-MS. The cumulative impact of mixed metal on stroke risk was investigated by using three statistical models, BKMR, WQS and QGC. RESULTS: The case group had higher concentrations of Mg, Mn, Zn, Se, Sn, and Pb than the control group (p<0.05). BKMR model indicated a correlation between the risk of stroke and exposure to mixed metals. WQS model showed that Mg (27.2 %), Se (25.1 %) and Sn (14.8 %) were positively correlated with stroke risk (OR=1.53; 95 %Cl: 1.03-2.37, p=0.013). The QGC model showed that Mg (49.2 %) was positively correlated with stroke risk, while Ti (31.7 %) was negatively correlated with stroke risk. CONCLUSIONS: Mg may be the largest contributor to the cumulative effect of mixed metal exposure on stroke risk, and the interaction between metals requires more attention. These findings could provide scientific basis for effectively preventing stroke by managing metals in the environment.

A rapid method for separation and identification of microcystins using capillary electrophoresis and time-of-flight mass spectrometry.

This paper demonstrates a method for the rapid separation and identification of four microcystin (MC) variants commonly found in aquatic environments. The procedure utilizes capillary electrophoresis (CE) coupled to UV absorbance and time-of-flight mass spectrometric (TOF-MS) detectors. All four analytes were effectively separated within 6min using phosphate buffer in 50-µm ID capillaries with an applied electric field of 400V/cm. The separation of the individual compounds was optimized through the adjustment of buffer, pH, and ß-cyclodextrin content. Ultimately it was determined that, at a sufficiently high pH, all 4 compounds could be separated without the need for added cyclodextrins. The results provided accurate molecular information, assisting in the determination of compound identity. The method was then applied to environmental samples using solid phase extraction for isolation and pre-concentration. The results were comparable to those obtained by LC/MS, but with a shorter run time and lower sample and eluent consumption.