Analysis Method And Application Of Chromium In Aquaculture Environment

In this paper,the method of morphological analysis of chromium in water and sediment of aquaculture was studied.The current selection of ultra-high sensitivity inductively coupled plasma mass spectrometry(ICP-MS)for metal element analysis was used to perform different forms of The chromium element content was determined by separating with the high-performance liquid chromatograph(HPLC)the different valence states of chromium element and applying it to the aquaculture environment water body and sediment samples.The result was satisfactory.Firstly,an HPLC-ICP-MS method was developed for the separation of Cr(III)and Cr(VI)from soluble chromium,and the collision gas,RF power and sampling depth,carrier gas flow rate,and spray chamber temperature were optimized.Conditions and chromatographic conditions such as column,column temperature,mobile phase type and concentration,elution mode,injection volume,and flow rate.Since Cr(III)and Cr(VI)exist as cations and anions,respectively,which increases the difficulty of simultaneous separation,Cr(III)is selected to be complexed as a coordinating anion with precolumn derivatization and the complexing agent is optimized.The correlation coefficients between species and concentration,complexation temperature and time,solution pH and other derivatization conditions,Cr(III)and Cr(VI)in the linear range of 0.1~20 ?g/L all reached 1.0000,and the detection limits were 0.034 ?g/L(?g/kg)and 0.049 ?g/L(?g/kg)respectively.Secondly,different forms of chromium in water samples of farms in some areas of Zhejiang Province were measured.Based on a 0.45 ?m microporous membrane,chromium in water samples was divided into particulate chromium and dissolved chromium,and total chromium was determined.With the content of dissolved chromium,the content of particulate chromium was obtained.In addition,the simultaneous determination of Cr(III)and Cr(VI)in dissolved chromium was performed by pre-column derivatization HPLC-ICP-MS.The content shows that the content of dissolved chromium in the tested sample is higher than that of the granular chromium,and the content of Cr(III)in the dissolved chromium is higher than that of Cr(VI).Finally,the sediment samples from the farms in some areas of Zhejiang Province were selected to analyze the different forms of chromium in the sediment samples.The continuous extraction method was used to classify the chromium in the sediment into exchangeable states(including water-soluble states),Carbonate bound state,Fe-Mn oxide bound state,Organic bound state,Residue state were studied,and the appropriate extraction method was selected according to different morphology,and the exchangeable state and carbonate therein were selected.The valence analysis was performed for the chromium elements in the two states of the bound state.The results showed that the chromium in the tested sediment samples was dominated by residual chromium,which accounted for about 80%,followed by organic bound chromium,which accounted for about 10%.The chromium content in the other three forms was relatively low.Its content is in the form of residual chromium> organic bound chromium> iron-manganese oxide bound chromium> ion-exchanged chromium> carbonate bound chromium.