The Research Of Multielement Species In Food And Water

Arsenic compounds exist in the nature widely, their poison dependon arsenic forms. Animals and plants absorb arsenic compounds whenthey grow up, as different regions have different arsenic distribution,arsenic compounds and their content in the body are different. The toxicof inorganic arsenic is bigge than organic, the more organic functionalgroup organic arsenic compound have, the smaller their toxicity are.Iodine, bromine compounds widely exist in soil、rock and water.Bromate can cause cancer after long-term accumulated in the body, butbromine is non-toxic. Animal experiments have found that high doses ofiodate is harmful to the body, while iodine is safe. So we should analyzearsenic、iodine and bromine species, for it can be more objective to assessthe safety of the food and natural environment.This paper analyzed the elements forms, included arseniccompounds of food, iodine and bromine compounds form in drinkingwater by High Performance Liquid Chromatography-Inductively CoupledPlasma Mass Spectrometry （HPLC-ICP-MS）.1、The research of arsenic forms in food （1） The nitric acid-water was used as extraction agent to extract fourarsenic compounds （As^Ⅲ, As^Ⅴ, DMA, MMA） in rice by heating extraction,HPLC-ICP-MS was used for analysis. Compared the nitric acidconcentration, extraction temperature, extracting time, optimized LCconditions to make each form get base separation. The paper used0.15mol·L^-1HNO3as extracting agent to pretreat rice sample under90℃inoven for2.5h. The linear ranges of the compounds were0.5-400.0μg·L^-1,r²＞0.9990, the detection limits of four arsenic forms were between0.06μg·L^-1and0.08μg·L^-1, the limits of quantitation were0.2-0.27μg·L^-1, therecoveries were in the range of73.7%-118.2%, The relative standarddeviation （RSD） were less than6%. The standard reference material wereused to verification. This method was successfully used in determinationthe real samples from market.（2） Ultrasonic-HPLC-ICP-MS was used to analyze five arseniccompounds （AsB, As^Ⅲ, As^Ⅴ, DMA, MMA） of fish, the nitric acid-waterwas used as extraction agents. The article compared ultrasonic-assistedextraction and oven heated extract, and chose ultrasonic as pretreatmethod; compared the extraction agents type and concentration；optimized LC conditions. The paper used0.28mol·L^-1HNO₃asextracting agent to pretreat samples for2h, then the extract solution wascooled, centrifuged and filmed. The linear ranges of the compounds were0.5-400.0μg·L^-1, r²＞0.9990, the LODs of four arsenic forms were between0.04μg·L^-1and0.08μg·L^-1, the LOQs were0.12-0.27μg·L^-1, therecoveries were in the range of80.0%-114.4%, The relative standarddeviation （RSD） were less than5%. This method was successfully used indetermination the fish samples.2、The research of iodine forms and bromide forms（1） HPLC-ICP-MS was used to analyze iodine compounds （IO₃^-, I^-）and bromide compounds （BrO₃^-, Br^-）in drinking water and mineral waterwith direct injection. This search optimized LC conditions, compared thepreservation conditions for iodine standard. The linear ranges of theiodine compounds were0.5-200.0μg·L^-1, r²＞0.9990; the linear ranges ofthe bromide compounds were2.5-200.0μg·L^-1, r²＞0.9990. The LODswere0.1-0.75μg·L^-1, the LOQs were0.4-2.5μg·L^-1, the recoveries werein the range of91.0%-118.2%, The relative standard deviation （RSD）were less than5%. The real samples were determined by this method, theresults were good.（2）It established the standard addition method to determine urineiodine by ICP-MS, this method is the the supplementary method of2012health standard urine iodine determination. The linear ranges of the iodinewere0.2-80.0μg·L^-1, r²＞0.9990; The LOD was0.05μg·L^-1, therecoveries were in the range of80.2%-108.2%, The relative standarddeviation （RSD） were less than5%. The method was used to determineurine iodine, the result were satisfied.