Dithizone Reagent, cov hmoov lead reagent, yog cov siv dav tshaj plaws ntawm cov organic chromogenic reagent hauv kev tshuaj ntsuam colorimetric. Nws tuaj yeem siv los txiav txim siab qhov hnyav hlau ions, xws li Pb, Hg, Zn, Cd, thiab lwm yam. Cov mis mos molecular yog C6H5NHNHCSN=NC6H5. Qhov tshwm sim yog xim liab-dub crystalline hmoov. Insoluble hauv dej thiab inorganic acids. Soluble nyob rau hauv chloroform thiab carbon tetrachloride, solubility nyob rau hauv chloroform yog zoo heev, thiab cov tshuaj yog ntsuab. Me ntsis soluble hauv hydrocarbon solvents. Ib tug hlau hloov ib tug nquag hydrogen atom nyob rau hauv nws cov molecule, thiab cov nitrogen atom tsim ib tug sib koom tes daim ntawv cog lus nrog cov hlau ion los tsim ib tug chelate complex. Cov tshuaj yog txiv kab ntxwv los yog liab, thiab cov tshuaj tiv thaiv yog empathetic. Nws yooj yim oxidized los ntawm huab cua thiab tuaj yeem tiv thaiv los ntawm kev ntxiv sulfur dioxide aqueous kua.
Npaj raws li nram no. 1. Kev npaj phenylhydrazine dithiocarboxylate phenylhydrazine ntsev. 13g ntawm phenylhydrazine tau yaj hauv 60ml ntawm ether, thiab 5.2ml ntawm carbon disulfide tau ntxiv dropwise. Lub resulting dawb precipitate yog lim tawm thiab ntxuav nrog ether kom txog 15 g. 2-Kev npaj ntawm diphenyldithiosemicarbazide. Cov khoom saum toj no tau muab tso rau hauv lub lauj kaub thiab rhaub hauv dej da dej ntawm 96-98 degree . Tom qab cov khoom tau melted, hydrogen sulfide raug tso tawm thiab tig mus rau hauv lub teeb daj jelly. Yog tias muaj cov evolution ntawm ammonia roj, tshem tawm cov da dej kub thiab txias nrog dej. Txias nrog dej khov dua. Tom qab ntawd txias nrog dej khov, ntxiv 15 ml ntawm anhydrous ethanol, tshem tawm los ntawm cov dej khov da dej, thiab cua sov me ntsis nrog nplawm. Cov tshuaj colloidal dhau los ua cov khoom siv crystalline, nqus pom, thiab ntxuav nrog ethanol kom tau txog 7.5 g. 3. Kev npaj ntawm nws. Cov diphenyldithiosemicarbazide tau los saum toj no tau ntxiv rau cov kua qaub potash (6g poov tshuaj hydroxide yaj hauv 60ml anhydrous methanol), refluxed hauv dej kub 5min, tshem tawm, thiab txias hauv da dej dej khov. Tom qab filtration, lub filtrate yog acidified nrog sulfuric acid kom txog rau thaum Congo liab daim ntawv xeem hloov xim, thiab ib tug tsaus xiav precipitate yog precipitated. Cov seem yog kho nrog caustic potash tov thiab sulfuric acid dua thiab ntxuav nrog dej tom qab nqus pom kom txog thaum tsis muaj sulfate radical. Qhuav ntawm 40 degree kom tau txog 3 g ntawm nws.
2. Txias qhov sib xyaw ntawm phenylhydrazine thiab toluene kom qis dua 0 degree, ntxiv carbon disulfide nyob rau hauv nplawm, thiab tswj tus nqi sib ntxiv kom tswj tau qhov ntsuas kub ntawm 60~70 degree . Tso nws rau ntau tshaj 10min, tom qab ntawd kub txog 90 ~ 95 degree, thiab cov muaju yaj. Thiab pib reacting. Thaum muaj coob tus crystals yog precipitated, thiab cov lead acetate reagent yog me ntsis xim av, cov tshuaj tiv thaiv tiav, lim tom qab txias, thiab cov muaju yog ntxuav nrog txias toluene thiab ethanol nyob rau hauv lem, thiab cov dawb crystals yog 3. Rau phenylthiocarbamide. Tom qab ntawd, diphenylcarbazide tau ntxiv rau cov tshuaj methanol ntawm poov tshuaj hydroxide, rhuab rau reflux rau 5 ~ 10min, txias rau li 30 degree nrog dej khov, lim kom tshem tawm cov teeb meem insoluble, thiab 0.5mol / L sulfuric acid ntxiv rau cov lim thaum nplawm. . Aqueous tov rau kev daws rau cov txiv hmab txiv ntoo liab daim ntawv xeem tsuas yog acidic. Cov crystals tau los ntawm kev pom yog ntxuav nrog dej txias, ces yaj nyob rau hauv ib tug 5 feem pua sodium hydroxide tov, thiab cov insoluble yog lim tawm. Cov lim dej yog txias nrog dej khov, thiab tib lub sijhawm, nws yog acidified nrog txias 0.5mol / L sulfuric acid rau Congo liab. Daim ntawv xeem tsuas yog acidic. Tom qab nag lossis daus tiav, lim nws. Cov purified crystals yog huv si ntxuav nrog dej khov kom txog thaum SO4 ion tsim nyog thiab ces qhuav ntawm 40 degree C kom tau cov khoom tiav, diphenylthiocarbazone.
Peb yog cov kws tshaj lijDithizone reagents tsum, yog tias koj muaj cov kev xav tau ntau, thov hu rau peb kom paub ntau ntxiv.