| Determination of geochemical samples of trace and ultratrace elements noblemetals havealways been an academic problems. The main difficulties are as fallow: first, the contentis too low, most of them do not reach the detection limit of the instrument, andchemical analysis are more difficult to obtain accurate values; Secondly, experimentalconditions are difficult to achieve. The main error during the experimental cannot beavoided. Thirdly, that have serious nugget effect; Fourth, Some methods of chemicalpre-treatment will be used poisonous drugs, it will have environmental pollutions andeffect.healthy. Based on the above points, it is very difficult to find the perfect method.So, the view of this paper to attempt to find a feasible and reliable analytical detectionmethods.The main contents of this paper are as follows:(1) Three kinds of complexing agents are:8-hydroxyquinoline, thiourea, ascorbicacid, hydroxylamine hydrochloride as modifier. The main methods of operation: theamount of test solution was added a solution of the complexing agent and then addingan appropriate amount of the modified active carbon adsorption, the final gray hair,dissolved determined.(2)8-hydroxyquinoline as complexing agent, modified activated carbon asadsorbent, by optimizing the experimental conditions established method fordetermining4kinds of geochemical soil samples.(3) Activated carbon,8-hydroxy quinoline and trioctylamine foam load agent.The main method is that Preparation of different load foam, and investigate the effects of loadagents on recovery.(4) Optional Trioctylamine load foam as adsorbent, by optimizing theexperimental conditions, to establish four kinds of geochemical soil samples were determined by the method samples.The paper concluded as follows:(1) Modified Activated comparison with unmodified Carbon Activated Carbon,the results showed that the recovery rate is generally low unmodified,modifiedactivated carbon is relatively good recovery.Determination of Osmium not highrecovery rate twice,mainly because of the volatile elements lose in the ashing process.Ruthenium and rhodium recovery of these two elements is not high,it may be thismethod is not suitable for the determination of these two elements.Gold,palladium,platinum-modified these three elements of recovery are very high,even withoutmodification,for gold recovery has reached more than70%.And both made ofactivated carbon infrared measurement found that the choice of the activated carbonitself comes amino-modified activated carbon and hydroxyl,hydroxyl adsorptioneffect on precious metals.（2）When ascorbic as complexing agent:The results showed that gold recoveriesare high,are more than130%,it can be inferred that the high gold content in thesample;When the amount of2.5ng/mL spiked when the maximum recovery ofplatinum and palladium,the data show that in the three experiments,the recovery ofplatinum and palladium is relatively stable cross,visible and effective method forplatinum and palladium.Osmium recovery has been low,indicating that is lost in theashing process;also a corresponding increase in these two elements ruthenium andrhodium concentration increases with spiked recoveries,ruthenium and rhodiumvisible effect of this method for higher concentrations of good.(3) When thiourea as a complexing agent,the data show when spiked when inaddition to the amount of osmium7ng/mL that recovery generally increased,decreased only gold recovery,but is the method in which the concentration of gold isnot very good.The overall increase can be seen spiked recoveries also increase.(4)8-hydroxyquinoline as complexing agent when the experimental data showthat when the amount of2.5ng/mL spiked when platinum palladium gold recoveriesare highest,with the increased volume spiked recovery of ruthenium and rhodium alsoincreased,while further ashing prove unsuitable for determination of osmium.(5)8-hy droxyquinoline as complexing agent, hydrochloric acid plus aqua regiadigestion system overnight at a temperature of20℃, pH of5or so, four sampleswere measured in the recovery of precious metals: Sample A, Au, Ru, Rh, Pd, Os andPt recoveries were103.4%,89.3%,59.8%,91.7%,17.9%and96.3%; sample B, Au,Ru, Rh, Pd, Os and Pt recoveries were102.8%,68.3%,70.9%,95.0%,27.8%and 89.6%; sample C, Au, Ru, Rh, Pd, Os and Pt recoveries were94.3%,81.9%,68.9%,92.3%,10.7%and92.3%; sample D, Au, Ru, Rh, Pd, Os and Pt recoveries were93.5%,61.5%,81.8%,97.6%,34.3%and94.6%.(6) Activated carbon load agent, Au, Ru, Rh, Pd, Os and Pt recoveries were100.5%,56.7%,46.9%,64.9%,10.7%,71.7%;8-hydroxyquinoline as load whenagents, Au, Ru, Rh, Pd, Os and Pt recoveries were89.1%,48.9%,11.6%,87.4%,20.8%and86.0%; trioctylamine when the load agent, Au, Ru, Rh, Pd, Os and Ptrecoveries were91.8%,60.8%,59.1%,91.6%,11.7%and87.1%. Found that whenTrioctylamine as complexing agent, the better.(7) At temperature of25℃, trinoctylamine foam adsorbent load, shock30min,the recovery of the four samples was measured as follows: Sample A, Au, Ru, Rh, Pd,Os and Pt the recoveries were88.9%,59.0%,40.8%,83.1%,5.6%and76.7%; sampleB, Au, Ru, Rh, Pd, Os and Pt recoveries were102.4%,62.2%,81.7%,98.6%,17.8%and94.5%; sample C, Au, Ru, Rh, Pd, Os and Pt recoveries were99.1%,98.6%,76.9%,93.5%,15.2%and99.1%; sample D, Au, Ru, Rh, Pd, Os and Pt recoverieswere83.3%,55.10%,82.7%,93.6%,26.1%and90.4%. |
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