The Study Of Determination Of Mercury In Environment By Different Means

Mercury(Hg)is the most common toxic heavy metal in the global environment,including lithosphere,hydrosphere,atmosphere and biosphere,and its toxicity is well known.Mercury is often difficult to control due to its volatility,mobility and biological enrichment.Mercury has many forms,including inorganic mercury,organic mercury,etc.,and organic mercury is more toxic.The detection requirements for different mercury forms are different.There are various types of mercury used in life,and the matrix of samples is more complex.Therefore,it is necessary to study a specific and comprehensive test method.In addition,the accumulation and persistent character of mercury species determine its large hazard even in trace levels.The sensitivity and accuracy of the detection method is also put forward higher requirements.It is the current focus that to research the detection method with low detection limit and high accuracy.In light of different samples of environment system,this research had developed two kinds of different test methods.One was the use of nano gold materials for determination of various mercury forms in environmental water samples.Another kind was to use the catalytic degradation of Fe3+ for the specific detection of thimerosal in vaccines.The results of the study are as follows:1.Using Fe3O4@PDA-Au NPs magnetic solid phase extraction and detection of mercury.A good stability of dopaminergic layer was formed on the surface of Fe3O4 nanoparticles by automatic polymerization of dopamine.Au3+ in HAuC14 solution diffused into the PDA layer and was reduced to AuO atom by the o-phenol group in the PDA,and the o-phenol was oxidized to the corresponding quinone.The adjacent AuO atoms clustered together to form Au NPs,indicating the successful synthesis of Fe3O4@PDA-Au NPs.In this experiment,transmission electron microscopy(TEM),scanning electron microscopy(SEM),vibrating sample magnetometry(VSM),and energy dispersive X-ray spectroscopy(EDS)were used to characterize surface morphology,internal structure,elemental composition,and magnetic strength of synthetic materials.Nano-gold could degrade organic mercury to inorganic mercury,eliminating the need for complicated digestion processes for mercury detection in samples,which made the detection method simpler and more environmentally friendly.In this study,experimental parameters affecting the extraction effect,such as pH,adsorbent extraction time,the type and concentration of the eluent,and interference ion were optimized.Under optimal experimental conditions,the detection limits of IHg and MMHg were both 0.75 ng L-1.The linear correlation coefficients of IHg and MMHg were 0.9987 and 0.9980 respectively.2.Non-chromatographic separation and determination of thimerosal and inorganic mercury in vaccines by Fe3+-induced degradation with cold vapor atomic fluorescence spectrometry.Iron ions had a catalytic effect on the reaction between borohydride and organic mercury.By introducing Fe3+ into cold atomic fluorescence spectrometer(CVAFS),an efficient,rapid,inexpensive,and environmentally friendly mercury speciation analysis method had been established.In this study,the experimental parameters affecting the sensitivity of the instrument were optimized.In the optimal experimental conditions,the detection limit of IHg and total mercury(THM)was 0.02,and 0.03 ?g L-1,respectively.The precision of IHg was 1.6%,and THM was 3.9%.The above two methods were aimed at the detection of mercury in environmental water and vaccine samples,respectively.The method were both targeted and comprehensive,high sensitivity,simple and easy to operate,green and environmental protection,without complicated process of digestion.