专着bismuth-二甲状腺素.pdf

USP35OfficialMonographs/Bismuth2369

Lossondrying〈731〉—Dryitat105°for3hours.ItlosesnotLimitofammoniumsalts—Boilabout100mgwith5mLof

morethan7.0%ofitsweight.1Nsodiumhydroxide:thevapordoesnotturnmoistenedred

Limitofnitrate—Mixabout100mgwith5mLof2Nsulfu-litmuspaperblue.

ricacidand5mLofferroussulfateTS,filterthemixture,andArsenic,MethodI〈211〉—Mix375mgwith5mLofwater,

carefullysuperimposethefiltrate,withoutmixing,on5mLofcautiouslyadd2mLofsulfuricacid,andheatthemixtureuntil

sulfuricacid,inatesttube:noreddishbrowncolorappearsatfumesofsulfurtrioxidearecopiouslyevolved.Cool,cautiously

thezoneofcontactofthetwoliquids.add10mLofwater,andagainevaporatetostrongfuming,

Arsenic—Triturate400mgwithanequalweightofcalciumrepeating,ifnecessary,toremoveanytraceofnitricacid.The

hydroxide,andignite.Dissolvetheresiduein5mLof3Nhy-limitis8ppm.

drochloricacid:thesolutionwithoutfurthertreatmentmeetsCopper—Toa5-mLportionofthetestliquidretainedinthe

therequirementsofthetestforArsenic〈211〉(7.5ppm).testforCarbonateaddaslightexcessof6Nammoniumhy-

Copper,Lead,andSilver—Ignite3ginaporcelaincrucible,droxide:theliquiddoesnotexhibitabluishcolor.

cool,andcautiouslyadd,dropwise,justsufficientnitricacidtoLead—Mixa5-mLportionofthetestliq