Dithizone, lub npe scientific diphenylcarbazone, tsos yog xim liab-dub crystalline hmoov. Nws yog ib qho nyuaj rau yaj nyob rau hauv dej thiab inorganic acids, me ntsis soluble nyob rau hauv cawv thiab ether, me ntsis soluble nyob rau hauv hydrocarbon solvents, thiab soluble nyob rau hauv sulfuric acid, alkali, thiab alkali hlau carbonates, thiab sai sai tig tsaus liab. Nws yooj yim rau yaj hauv chloroform thiab carbon tetrachloride thiab nthuav tawm ntsuab. Nws yog ntau soluble hauv chloroform. Nws cov tshuaj tsis ruaj khov thiab yooj yim rau oxygenated. Nws tuaj yeem tiv thaiv los ntawm ib txheej ntawm sulfur dioxide. Lub active hydrogen atom nyob rau hauv lub molecule yog hloov los ntawm hlau, thiab cov nitrogen atom tsim ib tug kev sib koom tes daim ntawv cog lus nrog hlau ions, chelate yog tsim. Cov tshuaj yog txiv kab ntxwv los yog liab, thiab cov tshuaj tiv thaiv yog rhiab heev. Nws yooj yim rau oxidized los ntawm huab cua thiab tuaj yeem tiv thaiv los ntawm kev ntxiv sulfur dioxide aqueous tov.
Discovery keeb kwm ntawm nws:
Cov tshuaj colorimetric reagent yog diphenyl thiocarbazone, uas tau tshawb pom los ntawm Emil Fischer hauv 1882. Nws pom tias nws yooj yim heev los tsim cov xim sib xyaw nrog cov hlau ions, tab sis nws tsis txuas ntxiv qhov kev tshawb fawb no. Xyoo 1926, Helmut Fischer tau kawm txog qhov sib xyaw no thiab qhia txog qhov muaj peev xwm siv nws rau kev txheeb xyuas, uas tau siv tag nrho hauv xyoo 1930.
Synthetic dithizone: npaj raws li cov kauj ruam hauv qab no.
1.) Kev npaj ntawm phenylhydrazine dithiocarbamate. Dissolve 13g ntawm phenylhydrazine hauv 60ml ntawm ether, thiab ntxiv 5.2ml ntawm carbon disulfide dropwise. Lim tawm cov av dawb tsim tawm thiab ntxuav nws nrog ether kom tau li 15g.
2.) kev npaj ntawm diphenyl Diaminothiourea. Muab cov khoom saum toj no tso rau hauv lub beaker thiab ua kom sov rau hauv ib da dej 96-98 degree. Tom qab melting, cov ntaub ntawv tso tawm hydrogen sulfide thiab tig mus rau yellowish colloids. Yog tias cov roj ammonia raug tso tawm, tshem tawm los ntawm da dej kub thiab txias nrog dej. Txias nrog dej khov. Tom qab ntawd txias nws nrog dej khov, ntxiv 15 ml ntawm dej tsis muaj ethanol, tshem tawm ntawm lub da dej dej khov, do thiab ua kom sov me ntsis. Lub sijhawm no, cov colloid hloov mus rau hauv cov khoom siv crystalline, lim nws, thiab ntxuav nws nrog ethanol kom tau txog 7.5G.
3.) kev npaj ntawm nws. Ntxiv cov lus hais saum toj no diphenyl diamino thiourea rau caustic potassium tov (6g poov tshuaj hydroxide yaj nyob rau hauv 60ml anhydrous methanol), reflux nyob rau hauv boiling dej da dej rau 5min, tshem tawm thiab txias nws nyob rau hauv ib tug dej khov da dej. Tom qab pom, cov filtrate yog acidified nrog sulfuric acid kom txog thaum Congo liab daim ntawv hloov xim thiab tsaus xiav precipitates raug cais tawm. Lim los ntawm kev nqus, thiab tom qab ntawd kho cov av nrog caustic potassium tov thiab sulfuric acid. Tom qab pom, ntxuav nrog dej kom txog thaum tsis muaj sulfate radical. Qhuav ntawm 40 degree muab txog 3G.
Kev txiav txim siab ntawm mercury hauv dej los ntawm spectrophotometric txoj cai: zom cov qauv nrog poov tshuaj permanganate thiab poov tshuaj persulfate ntawm 95 degree, hloov tag nrho cov mercury uas muaj nyob rau hauv divalent mercury, thiab txo cov oxidant ntau tshaj nrog hydroxylamine hydrochloride, nyob rau hauv acidic tej yam kev mob, mercury ions react nrog ntxiv. Nws cov tshuaj los ua cov txiv kab ntxwv chelate, rho tawm nrog cov kuab tshuaj organic, ntxuav tawm qhov ntau dhau nrog cov tshuaj alkali, thiab ntsuas qhov nqus ntawm lub wavelength ntawm 485nm, xam cov ntsiab lus mercury hauv dej los ntawm txoj kev nkhaus txheem. Rau kev txiav txim siab ntawm mercury hauv dej los ntawm spectrophotometry, saib kev txiav txim siab ntawm tag nrho cov mercury hauv dej zoo potassium permanganate potassium persulfate digestion spectrophotometric (gb7469-87). zom cov qauv nrog poov tshuaj permanganate thiab poov tshuaj persulfate ntawm 95 degree, hloov tag nrho cov mercury uas muaj nyob rau hauv divalent mercury, thiab txo cov oxidant ntau tshaj nrog hydroxylamine hydrochloride, nyob rau hauv acidic tej yam kev mob, mercury ion reacts nrog ntxiv tov los tsim ib tug txiv kab ntxwv chelate, extract. nrog cov kuab tshuaj organic, ntxuav tawm qhov ntau dhau nrog cov tshuaj alkali, ntsuas qhov nqus ntawm lub wavelength ntawm 485nm, thiab suav cov ntsiab lus mercury hauv dej nrog cov qauv nkhaus. Chloroform los yog carbon tetrachloride tuaj yeem siv los ua cov kuab tshuaj organic lossis cov extractant. Cov qub yog dav siv vim nws cov toxicity tsawg. Qhov tsawg kawg nkaus pom tau qhov concentration ntawm mercury yog 2PG / L thiab qhov siab tshaj ntawm kev txiav txim siab yog 40pg / L. Nws muaj feem xyuam rau kev saib xyuas cov dej khib nyiab thiab cov dej saum npoo av uas muaj mercury. Txoj kev no muaj cov kev cai nruj heev rau kev tswj xyuas kev txiav txim siab. Hauv particular, qhov purity thiab ntau npaum li cas ntawm reagents yog heev xav tau. Nws yuav tsum tau muab sau tseg tias Mercury yog ib yam tshuaj lom heev. Cov tshuaj chloroform uas muaj mercury dithizone tom qab rho tawm yuav tsum tsis txhob muab pov tseg. Sulfuric acid yuav tsum tau muab ntxiv los rhuav tshem cov xim chelate thiab cais nws los ntawm lwm yam impurities nyob rau hauv cov dej theem, thiab tom qab ntawd cov chloroform yuav tsum tau rov qab los ntawm re-steaming. Cov kua khib nyiab uas muaj mercury yog nruab nrab nrog sodium hydroxide tov kom txog thaum nws yog me ntsis alkaline, thiab ces sodium sulfide tov yog ntxiv nyob rau hauv nplawm kom tag nrho precipitate mercury, thiab precipitate yog zoo los yog lwm yam kho. Yuav ua li cas txiav txim siab methylmercury hauv dej? Methylmercury hauv dej tuaj yeem txiav txim siab los ntawm roj chromatography. Yog xav paub meej, thov xa mus rau qhov kev txiav txim siab ntawm methylmercury hauv ib puag ncig los ntawm roj chromatography (GB / T 17132-1997). Txoj kev no yog tsim rau kev txiav txim siab ntawm methylmercury hauv dej nto, dej haus, dej phwj tuaj hauv tsev, dej khib nyiab, sediment, ntses lub cev, tib neeg cov plaub hau, thiab zis. (rau cov ntaub ntawv xov xwm ntxiv txog kev tshuaj xyuas zoo, kev tshuaj xyuas thiab kev sim, stoichiometry thiab cov ntaub ntawv siv, thov xa mus rau lub teb chaws cov ntaub ntawv www.rmhot.com) ua ntej, cov qauv dej yuav tsum tau pretreated los txhawb cov ntsiab lus ntawm methyl mercury rau cov kev cai ntawm Kev txiav txim siab, thiab tom qab ntawd cov ntsiab lus ntawm methyl mercury hauv cov qauv yuav tsum txiav txim siab los ntawm cov roj chromatography (cov khoom siv hluav taws xob ntes). Txoj kev pretreatment thiab qhov tsawg kawg nkaus nrhiav kom pom concentration yog sib txawv rau cov qauv sib txawv. Methyl mercury nyob rau hauv dej, sediment thiab tso zis tau txiav txim los ntawm txoj kev pretreatment ntawm theem nrab enrichment nrog sulfhydryl gauze thiab sulfhydryl paj rwb. Qhov ntsuas pom tau yog 0 01ng / l, 0.02ug / kg, thiab 2ng / L raws li; Methylmercury nyob rau hauv cov ntses thiab tib neeg cov plaub hau yog txiav txim los ntawm pretreatment txoj kev ntawm hydrochloric acid kua extraction. Qhov ntsuas pom tau yog 0.1pg / l thiab 1ug / kg, feem.