general tests, processes and apparatus

248 Pages·2007·4.76 MB·English

GENERAL TESTS, PROCESSES
AND APPARATUS
GeneralTests,ProcessesandApparatusincludescommon general testmethod.
methodsfortests,usefultestmethodsforqualityrecognition
1. Chemical Methods
ofdrugsandotherarticlesrelatedtothem.Unlessotherwise
speciˆed,theproceduresforacid-neutralizingcapacitydeter-
mination of gastrointestinal medicines, alcohol number de-
termination, ammonium determination, arsenic determina-
1.01 Alcohol Number
tion,atomicabsorptionspectrophotometry,testforbacterial
endotoxins, boiling point determination, distilling range de- Determination
termination, chloride determination, conductivity measure-
ment,congealingpointdetermination,determinationofbulk
Alcohol Number Determination represents the number of
andtappeddensities,digestiontest,disintegrationtest,disso-
milliliters of ethanol at 159C obtained from 10mL of tin-
lution test,endpointdetectionintitrimetry,testofextracta-
ctureorotherpreparationscontainingethanolbythefollow-
ble volume for injection, ‰ame coloration, ‰uorometry,
ing procedures.
foreign insoluble matter test for injections, gas chro-
matography, heavy metals determination, test for glass Method 1 Distilling method
containers for injections, infrared spectrophotometry, This is a method to determine the Alcohol Number by
insoluble particulate matter test for injections, insoluble readingthenumberofmillilitersofethanoldistillateat159C
particulate matter test for ophthalmic solutions, iron deter- obtained from 10mL of a sample measured at 159C by the
mination,liquidchromatography,lossondryingdetermina- following procedures.
tion,lossonignitiondetermination,meltingpointdetermina- (1) Apparatus
tion, test for metal particles in ophthalmic ointments, Use hard glass apparatus as illustrated in Fig. 1.01-1.
methanoldetermination,microbialassayforantibiotics,test Ground glass may be used for the joints.
for microbial limit, test for microbial limit for crude drugs, (2) Reagent
mineral oil determination, nitrogen determination, nuclear Alkalinephenolphthaleinsolution:To1gofphenolphtha-
magnetic resonance spectroscopy, optical rotation determi- leinadd7mLofsodiumhydroxideTSandwatertomake100
nation, osmolarity determination, oxygen ‰ask combustion mL.
method, particle size distribution test for preparations, pH (3) Procedure
determination, test for plastic containers, powder particle Transfer 10mL of the sample preparation, accurately
density determination, powder particle size determination, measuredat15±29C,tothedistilling‰askA,add5mLof
testforpyrogen,qualitativetest,testforreadilycarbonizable water and boiling chips. Distil ethanol carefully into the
substances, refractive index determination, residualsolvents glass-stoppered, volumetric cylinder D.
test, residue on ignition determination, test for rubber ByreferencetoTable1.01-1,asuitablevolumeofdistillate
closure for aqueous infusions, speciˆc gravity and density (mL)shouldbecollected,accordingtothecontentofethanol
determination, speciˆc surface area determination, test for in the samplepreparation.
sterility, sulfate determination, thermal analysis, thin-layer Prevent bumping during distillation by rendering the
chromatography, test for total organic carbon, ultraviolet- samplestronglyacidicwithphosphoricacidorsulfuricacid,
visible spectrophotometry, uniformity of dosage units (test orbyaddingasmallamountofpara‹n,beeswaxorsilicone
for content uniformity, mass variation test), viscosity resin before starting thedistillation.
determination, vitamin A assay, water determination, and Whenthesamplescontainthefollowingsubstances,carry
X-ray powder diŠraction are performed as directed in the outpretreatment as follows before distillation.
corresponding articles under the General Tests, Processes (i) Glycerin: Add su‹cient water to the sample so that
andApparatus.Thetestsformeltingpointoffats,congeal- theresidueinthedistilling‰ask,afterdistillation,containsat
ingpointoffattyacids,speciˆcgravity,acidvalue,saponiˆ- least50z of water.
cationvalue,estervalue,hydroxylvalue,unsaponiˆablemat- (ii) Iodine:Decolorize the sample with zinc powder.
ter and iodine value of fats and fatty oils are performed as (iii) Volatile substances: Preparations containing ap-
directedinthecorrespondingitemsunderFatsandFattyOils preciable proportions of essential oil, chloroform, diethyl
Test, and sampling, preparation of sample for analysis, etherorcamphorrequiretreatmentasfollows.Mix10mLof
microscopic examination, purity test, loss on drying, total the sample, accurately measured, with 10mL of saturated
ash,acid-insolubleash,extractcontent,andessentialoilcon- sodium chloride solution in a separator, add 10mL of
tent of crude drugs are performed as directed in the corre- petroleumbenzin,and shake.Collecttheseparated aqueous
sponding items under Crude Drugs Test. layer. The petroleum benzin layer was extracted with two 5
The number of each test method is a category number mLportionsofsaturatedsodiumchloridesolution.Combine
given individually. The number in blackets (< >) appeared the aqueous layers, and distill. According to the ethanol
in monograph indicates the number corresponding to the contentinthesample,collectavolumeofdistillate2to3mL
1177
1188 Alcohol Number Determination / General Tests JP XV
Table 1.01-1 to 2 drops of alkaline phenolphthalein solution, and shake
vigorously. If the aqueous layer shows no white turbidity,
Ethanolcontentin Distillate
agitate the distillate with additional potassium carbonate.
thesample(volz) tobecollected(mL)
Afterallowingtostandinwaterat15±29Cfor30minutes,
morethan80 13 read the volume of the upper reddish ethanol layer in mL,
80–70 12
and regard it as the Alcohol Number. If there is no clear
70–60 11
boundarysurfacebetweenthesetwolayers,shakevigorously
60–50 10
after addition of a few drops of water, then observe in the
50–40 9
same manner.
40–30 8
lessthan30 7
Method 2 Gas chromatography
Thisisamethodtodeterminethealcoholnumberbydeter-
mining ethanol (C HOH) content (volz) from a sample
2 5
measured at159C by thefollowing procedures.
(1) Reagent
Ethanol for alcohol number: Ethanol (99.5) with deter-
mined ethanol (CH OH) content. The relation between
2 5
speciˆc gravity d15 of ethanol and content of ethanol
15
(C HOH) is 0.797:99.46 volz, 0.796:99.66 volz, and
2 5
0.795:99.86 volz.
(2) Preparationofsamplesolutionandstandardsolution
Sample solution: Measure accurately a volume of sample
at15±29Cequivalenttoabout5mLofethanol(CHOH),
2 5
and add water to make exactly 50mL. Measure accurately
25mL of this solution, add exactly 10mL of the internal
standard solution,and add waterto make100mL.
Standardsolution:Measureaccurately5mLofethanolfor
alcohol number at the same temperature as the sample, and
addwatertomakeexactly50mL.Measureaccurately25mL
of this solution, add exactly 10mL of the internal standard
solution, and add water to make 100mL.
(3) Procedure
Place25mLeachofthesamplesolutionandthestandard
solution in a 100-mL, narrow-mouthed, cylindrical glass
bottle sealed tightly with a rubber closure and aluminum
band,immersethebottleuptotheneckinwater,allowedto
stand at room temperature for more than 1 hour in a room
with little change in temperature, shake gently so as not to
splashthesolutionontheclosure,andallowtostandfor30
minutes. Perform the test with 1mL each of the gas in the
bottle with a syringe according to the Gas Chromatography
<2.02> under the following conditions, and calculate the
ratios,Q andQ ,ofthepeakheightofethanoltothatofthe
T S
internalstandard.
Q 5(mL)
Alcoholnumber＝ T ×
Q a volume (mL) of sample
S
ethanol(C HOH)content (volz)of
2 5
ethanolforalcoholnumber
×
9.406
Internal standard solution—A solution of acetonitrile (3 in
50).
Fig. 1.01-1
Operating conditions—
Detector: Ahydrogen ‰ame-ionization detector.
morethan that shown in the above Table. Column: A glass tube about 3mm in inside diameter and
(iv) Other substances: Render preparations containing about 1.5m in length, packed with 150- to 180-mm porous
free ammonia slightly acidic with dilute sulfuric acid. If ethylvinylbenzene-divinylbenzene copolymer (mean pore
volatile acids are present, render the preparation slightly size:0.0075mm, 500–600m2Wg) for gas chromatography.
alkaline with sodium hydroxide TS, and if the preparations Column temperature: A constant temperature between
contain soap along with volatile substances, decompose the 1059C and 1159C.
soapwith anexcessofdilutesulfuricacidbeforetheextrac- Carriergas:Nitrogen
tionwithpetroleumbenzininthetreatmentdescribedin(iii). Flowrate:Adjustthe‰owratesothattheretentiontimeof
Tothedistillateadd4to6gofpotassiumcarbonateand1 ethanol is5 to 10 minutes.
JP XV General Tests / Ammonium Limit Test 1199
Selection of column: Proceed with 1mL of the gas ob-
tained from the standard solution in the bottle under the
aboveoperatingconditions,andcalculatetheresolution.Use
acolumngivingelutionofethanolandtheinternalstandard
in this order with the resolution between these peaks being
notless than 2.0.
1.02 Ammonium Limit Test
Ammonium LimitTestis alimittest for ammonium con-
tained in drugs.
In each monograph, the permissible limit for ammonium
(as NH＋) is described in terms of percentage (z) in paren-
4
theses.
Apparatus
Useadistillingapparatusforammoniumlimittestasillus-
tratedinFig.1.02-1.Forthedistillationunderreducedpres-
sure,usetheapparatusshowninFig.1.02-2.Eitherappara-
tusarecomposedofhardglass,andground-glassjointsmay
be used. All rubber parts used in the apparatus should be
boiledfor10to30minutesinsodiumhydroxideTSandfor
30to60minutesinwater,andˆnallywashedthoroughlywith
water before use.
Procedure
(1) Preparation of test solution and control
Fig. 1.02-2 Vacuum distilling apparatus for ammonium
solution—Unlessotherwisespeciˆed,testsolutionsandcon-
limit test
trol solution are prepared as directed in the following.
Place an amount of the sample, directed in the mono-
graph,inthedistilling‰askA.Add140mLofwaterand2g
givearateof5to7mLperminuteofdistillate,anddistillun-
ofmagnesiumoxide,andconnectthedistillationapparatus.
til the distillate measures 60mL. Remove the receiver from
To the receiver (measuring cylinder) F add 20mL of boric
the lower end of the condenser, rinsing the end part with a
acid solution (1 in 200) as an absorbing solution, and im-
smallquantityofwater,addsu‹cientwatertomake100mL
mersethelowerendofthecondenser.Adjusttheheatingto
and designate itasthetestsolution.
For the distillation under reduced pressure, take the
amountofsamplespeciˆedinthemonographtothevacuum
distillation‰askL,add70mLofwaterand1gofmagnesium
oxide, and connect to the apparatus (Fig. 1.02-2). To the
receiverMadd20mLofasolutionofboricacid(1in200)as
absorbingliquid,puttheendofthebranchtubeofthedistil-
lation‰askLintheabsorbingliquid,andkeepat609Cusing
a water bath or alternative equipment. Adjust the reduced
pressuretogetthedistillateatarateof1to2mLperminute,
and continue the distillation until to get30mL of the distil-
late.CoolthereceiverMwithrunningwaterduringthedistil-
lation.GetoŠtheendofthebranchtubefromsurfaceofthe
absorbing liquid, rinse in the end with a small amount of
water,thenaddwatertotheliquidtomake100mL,andper-
form thetest using this solution as the test solution.
PlaceavolumeofStandardAmmoniumSolution,directed
inthemonograph,inthedistilling‰askAorthevacuumdis-
tillation‰askL,proceedasforthepreparationofthetestso-
lution,and designateit as the control solution.
(2) Test of the test solution and the control
solution—Unless otherwise speciˆed, proceed as directed in
the following.
Place30mLeachofthetestsolutionandthecontrolsolu-
tion in Nessler tubes, add 6.0mL of phenol-sodium pentac-
yanonitrosylferrate(III)TStoeachsolution,andmix.Then
add4mLofsodiumhypochlorite-sodiumhydroxideTSand
Fig. 1.02-1 Distilling apparatus for ammonium limit test water to make 50mL, mix, and allow to stand for 60
2200 Chloride Limit Test / General Tests JP XV
minutes.Comparethecolorofbothsolutionsagainstawhite
1.05 Mineral Oil Test
backgroundbyviewing downward ortransversely:thecolor
developedinthetestsolutionisnotmoreintensethanthatof
the control solution. MineralOilTestisamethodtotestmineraloilinnonaque-
oussolventsforinjectionsand foreye drops.
Procedure
1.03 Chloride Limit Test
Pour10mLofthesampleintoa100-mL‰ask,andadd15
mL of sodium hydroxide solution (1 in 6) and 30mL of
ChlorideLimitTestisalimittestforchloridecontainedin ethanol(95).Putashort-stemmed,smallfunnelontheneck
drugs. ofthe‰ask,andheatonawaterbathtomakeclear,withfre-
In each monograph, the permissible limit for chloride (as quent shaking. Then transfer the solution to a shallow por-
Cl) isdescribed in terms of percentage (z) in parentheses. celain dish, evaporate the ethanol on a water bath, add 100
mLofwatertotheresidue,andheatonawaterbath:notur-
Procedure
bidity isproduced in the solution.
Unless otherwise speciˆed, transfer the quantity of the
sample, directed in the monograph, to a Nessler tube, and
dissolveitinapropervolumeofwatertomake40mL.Add6
1.06 Oxygen Flask Combustion
mL of dilute nitric acid and water to make 50mL, and use
thissolutionasthetestsolution.Transferthevolumeof0.01 Method
molWL hydrochloric acid VS, directed in the monograph,to
anotherNesslertube,add6mLofdilutenitricacidandwater
Oxygen Flask Combustion Method is a method for the
tomake50mL,andusethissolutionasthecontrolsolution.
identiˆcation or the determination of halogens or sulfur
When the test solution is not clear, ˆlter both solutions by
producedbycombustingorganiccompounds,whichcontain
using the same procedure.
chlorine,bromine,iodine,‰uorineorsulfur,ina‰askˆlled
Add1mLofsilvernitrateTStothetestsolutionandtothe
with oxygen.
controlsolution,mixwell,andallow tostand for5 minutes
protecting from direct sunlight. Compare the opalescence Apparatus
developed in both solutions against a black background by Use theapparatus shown in Fig. 1.06-1.
viewing downward or transversely.
Preparation oftest solution and blank solution
Theopalescencedevelopedinthetestsolutionisnotmore
Unless otherwise speciˆed, prepare them by the following
than that of thecontrolsolution.
method.
(1) Preparation of sample
(i) For solid samples: Place the quantity of the sample
1.04 Flame Coloration Test
speciˆedinthemonographonthecenteroftheˆlterillustrat-
edintheˆgure,weighaccurately,wrapthesamplecarefully
FlameColorationTestisamethodtodetectanelement,by alongthedottedlinewithoutscattering,andplacetheparcel
meansofthepropertythattheelementchangesthecolorless in a platinum basket or cylinder B, leaving its fuse-strip on
‰ame of a Bunsen burnerto its characteristic color. the outside.
(1) Saltofmetal—Theplatinumwireusedforthistestis (ii) Forliquidsamples:Rollasuitableamountofabsor-
about0.8mmindiameter,andtheendpartofitisstraight. bent cotton with ˆlter paper, 50mm in length and 5mm in
Inthecaseofasolidsample,makethesampleintoagruelby width,sothattheendpartofthepaperislefttoalengthof
addingasmallquantityofhydrochloricacid,applyalittleof about 20mm as a fuse-strip,and place theparcelin a plati-
the gruelto the 5-mm end of the platinum wire, and testby numbasketorcylinderB.Placethesampleinasuitableglass
putting the end part in a colorless ‰ame, keeping the plati- tube, weigh accurately, and moisten the cotton with the
numwirehorizontal.Inthecaseofaliquidsample,immerse quantityofthesamplespeciˆed in themonograph,bringing
theendoftheplatinumwireintothesampletoabout5mmin the edge of the sample in contact with thecotton.
length,removefromthesamplegently,andperformthetest (2) Method of combustion
in the same manner as for the solid sample. Place the absorbing liquid speciˆed in the monograph in
(2) Halide—Cut a copper net, 0.25mm in opening and ‰ask A, ˆll it with oxygen, moisten the ground part of the
0.174mminwirediameter,intoastrip1.5cminwidthand5 stopper C with water, then ignite the fuse-strip, immediatey
cm in length, and wind in round one end of a copper wire. transfer it to the ‰ask, and keep the ‰ask airtight until the
Heatthecoppernetstronglyinthecolorless‰ameofBunsen combustion is completed. Shake the ‰ask occasionally until
burneruntilthe‰amenolongershowsagreenorbluecolor, thewhitesmokeinAvanishescompletely,allowtostandfor
and then cool it. Repeat this procedure several times, and 15to 30 minutes,and designatetheresultingsolution asthe
coatthenetcompletelywithcupricoxide.Aftercooling,un- testsolution.Preparetheblanksolutioninthesamemanner,
less otherwise speciˆed, apply about 1mg of the sample to withoutsample.
the copper net, ignite, and burn it. Repeat this procedure
Procedure ofdetermination
three times, and then test by putting the copper net in the
Unlessotherwisespeciˆedinthemonograph,performthe
colorless‰ame.
testasfollows.
The description,``Flame coloration persists'',in a mono-
(1) Chlorine and bromine
graph,indicates thatthe reaction persistsfor 4 seconds.
ApplyasmallamountofwatertotheupperpartofA,pull
JP XV General Tests / Heavy Metals Limit Test 2211
Each mL of 0.005molWL silver nitrate VS
＝0.6345mg of I
(3) Fluorine
ApplyasmallamountofwatertotheupperpartofA,pull
outCcarefully,transferthetestsolutionandtheblanksolu-
tionto50mLvolumetric‰asksseparately,washC,Bandthe
inner side of A with water, add the washings and water to
make50mL,andusethesesolutionsasthetestsolutionand
thecorrectionsolution.Pipetthetestsolution(VmL)equiva-
lenttoabout30ngof‰uorine,VmLofthecorrectionsolu-
tion and 5mL of standard ‰uorine solution, transfer to
50-mL volumetric‰asksseparately,add 30mL ofamixture
of alizarin complexone TS, acetic acid-potassium acetate
buŠer solution, pH 4.3 and cerium (III) nitrate TS (1:1:1),
addwatertomake50mL,andallowtostandfor1hour.Per-
form the test with these solutions as directed under Ultrav-
iolet-visible Spectrophotometry <2.24>, using a blank pre-
paredwith5mLofwaterinthesamemanner.Determinethe
absorbances,A ,A andA ,ofthesubsequentsolutionsof
T C S
thetestsolution,thecorrectionsolutionandthestandardso-
lution at600nm.
Amount(mg)of ‰uorine (F)in the test solution
＝amount (mg) of ‰uorine in 5mL of
A －A 50
the standard solution× T C ×
A V
S
StandardFluorineSolution:Drysodium‰uoride(standard
reagent)inaplatinumcruciblebetween5009Cand5509Cfor
1hour, cool it in a desiccator (silica gel), weigh accuraly
about66.3mgofit,anddissolveinwatertomakeexactly500
mL. Pipet 10mL of this solution, and dilute with su‹cient
water to makeexactly 100mL.
Fig. 1.06-1 (4) Sulfur
ApplyasmallamountofwatertotheupperpartofA,pull
outCcarefully,andwashC,BandtheinnersideofAwith
out C carefully, and transfer the test solution to a beaker.
15mLofmethanol.Tothissolutionadd40mLofmethanol,
WashC,BandtheinnersideofAwith15mLof2-propanol,
then add exactly 25mL of 0.005molWL barium perchlorate
andcombinethewashingswiththetestsolution.Tothissolu-
VS,allowtostandfor10minutes,add0.15mLofarsenazo
tion add 1 drop of bromophenol blue TS, add dilute nitric
 TS with a measuring pipet, and titrate <2.50> with 0.005
aciddropwiseuntilayellowcolordevelops,thenadd25mL
molWLsulfuricacidVS.Perfromthetestwiththeblanksolu-
of2-propanol,andtitrate<2.50>with0.005molWL silverni-
tion in the samemanner.
trate VS according to the potentiometric titration under the
Electrometrictitration.Performthetestwiththeblanksolu- Each mL of 0.005molWL barium perchlorate VS
tioninthesamemanner,andmakeanynecessarycorrection. ＝0.1604mg of S
Each mL of 0.005molWL silver nitrate VS
＝0.1773mg of Cl
1.07 Heavy Metals Limit Test
Each mL of 0.005molWL silver nitrate VS
＝0.3995mg of Br
Heavy Metals Limit Test is a limit test of the quantity of
(2) Iodine
heavy metals contained as impurities in drugs. The heavy
ApplyasmallamountofwatertotheupperpartofA,pull
metalsarethemetallicinclusionsthataredarkenedwithsodi-
outCcarefully,add2dropsofhydrazinehydratetothetest
umsulˆdeTSinacidicsolution,astheirquantityisexpressed
solution,putConA,anddecolorizethesolutionbyvigorous
in terms of the quantity of lead (Pb).
shaking. Transfer the content of A to a beaker, wash C, B
Ineachmonograph,thepermissiblelimitforheavymetals
andtheinnersideofAwith25mLof2-propanol,andtrans-
(asPb)is described in terms ofppm in parentheses.
ferthewashingstotheabovebeaker.Tothissolutionadd1
drop of bromophenol blue TS, then add dilute nitric acid Preparation oftest solutions and controlsolutions
dropwiseuntilayellowcolordevelops,andtitrate<2.50>with Unlessotherwisespeciˆed,testsolutionsandcontrolsolu-
0.005molWL silvernitrate VS according to thePotentiomet- tions are prepared as directed in the following:
ric tiration under Electrometric Titration. Perform the test (1) Method 1
with the blank solution in the same manner, and make any Place an amount of the sample, directed in the mono-
necessary correction. graph, in a Nessler tube. Dissolve in water to make 40mL.
2222 Nitrogen Determination (Semimicro-Kjeldahl Method) / General Tests JP XV
Add2mLofdiluteaceticacidandwatertomake50mL,and 50mL, and use this solution as the test solution.
designate itasthe testsolution. Thecontrolsolutionispreparedasfollows:Take10mLof
Thecontrolsolutionisprepared byplacingthevolumeof asolutionofmagnesiumnitratehexahydrateinethanol(95)
StandardLeadSolutiondirectedinthemonographinaNess- (1 in 10), and ˆre the ethanol to burn. Cool, add 1mL of
lertube,and adding 2mL ofdilute acetic acid and waterto sulfuric acid, heat carefully, and ignite between 5009C and
make 50mL. 6009C. Cool, and add 3mL of hydrochloric acid. Here-
(2) Method 2 inafter,proceedasdirectedinthetestsolution,thenaddthe
Place an amount of the sample, directed in the mono- volume of Standard Lead Solution directed in the mono-
graph,inaquartzorporcelaincrucible,coverlooselywitha graph and water to make 50mL.
lid,andcarbonizebygentleignition.Aftercooling,add2mL
Procedure
ofnitricacidand5dropsofsulfuricacid,heatcautiouslyun-
Add 1 drop ofsodium sulˆdeTS to each of the test solu-
tilwhitefumesarenolongerevolved,andincineratebyigni-
tion and the control solution, mix thoroughly, and allow to
tion between 5009C and 6009C. Cool, add 2mL of
stand for 5 minutes. Then compare the colors of both solu-
hydrochloric acid, evaporate to dryness on a water bath,
tionsbyviewingthetubesdownwardortransverselyagainsta
moistentheresiduewith3dropsofhydrochloricacid,add10
whitebackground.Thetestsolutionhasnomorecolorthan
mLofhotwater,andwarmfor2minutes.Thenadd1drop
the control solution.
of phenolphthalein TS,add ammonia TS dropwiseuntilthe
solutiondevelopsapaleredcolor,add2mLofdiluteacetic
acid, ˆlter if necessary, and wash with 10mL of water.
1.08 Nitrogen Determination
TransfertheˆltrateandwashingstoaNesslertube,andadd
water to make 50mL. Designate it as the test solution. (Semimicro-Kjeldahl Method)
The control solution is prepared as follows: Evaporate a
mixtureof2mLofnitricacid,5dropsofsulfuricacidand2
Nitrogen Determination is a method to determine ammo-
mL ofhydrochloric acid on a water bath,furtherevaporate
nia in ammonium sulfate obtained by decomposition of or-
to dryness on a sand bath, and moisten the residue with 3
ganicsubstances containing nitrogen with sulfuricacid.
dropsofhydrochloricacid.Hereinafter,proceedasdirected
in the test solution, then add the volume of Standard Lead Apparatus
Solution directed in the monograph and water to make 50 UsetheapparatusillustratedinFig.1.08-1.Itisthorough-
mL. ly constructed of hard glass, and ground glass surfaces may
(3) Method 3 be used for joints. All rubber parts used in the apparatus
Place an amount of the sample, directed in the mono- shouldbeboiledfor10to30minutesinsodiumhydroxideTS
graph, in a quartz or porcelain crucible, heat cautiously, and for 30 to 60 minutes in water, and ˆnally washed
gentlyatˆrst,andthenincreasetheheatuntilincinerationis thoroughly with water before use.
completed.Aftercooling,add1mLofaquaregia,evaporate
Procedure
todrynessonawaterbath,moistentheresiduewith3drops
Unless otherwise speciˆed, proceed by the following
ofhydrochloricacid,add10mLofhotwater,andwarmfor
method. Weigh accurately or pipeta quantity ofthesample
2minutes.Add1dropofphenolphthaleinTS,addammonia
correspondingto2to 3mgofnitrogen(N:14.01),and place
TSdropwiseuntilthesolutiondevelopsapaleredcolor,add
intheKjeldahl‰askA.Add1gofapowderedmixtureof10
2mL of dilute acetic acid, ˆlter if necessary, wash with 10
gofpotassiumsulfateand1gofcupper(II)sulfatepentahy-
mL of water, transfer the ˆltrate and washings to a Nessler
drate.Washdownanyadheringsamplefromtheneckofthe
tube,andaddwatertomake50mL.Designateitasthetest
‰ask with a small quantity of water. Add 7mL of sulfuric
solution.
acid, allowing it to ‰ow down theinside wallofthe ‰ask.
The control solution is prepared as follows: Evaporate 1
Then, while shaking the ‰ask, add cautiously 1mL of
mL of aqua regia to dryness on a water bath. Hereinafter,
hydrogenperoxide(30)dropbydropalongtheinsidewallof
proceedasdirectedforthetestsoluttion,andaddthevolume
the ‰ask. Heat the ‰ask gradually, then heat so strong that
of Standard Lead Solution directed in the monograph and
the vapor of sulfuric acid is condensed at the neck of the
water to make 50mL.
‰ask,untilthesolutionchangesthroughablueandcleartoa
(4) Method 4
vivid green and clear, and the inside wall of the ‰ask isfree
Place an amount of the sample, directed in the mono-
from a carbonaceous material. If necessary, add a small
graph,inaplatinumorporcelaincrucible,mixwith10mLof
quantity of hydrogen peroxide (30) after cooling, and heat
asolutionofmagnesiumnitratehexahydratein ethanol(95)
again.Aftercooling,addcautiously20mLofwater,coolthe
(1in 10),ˆretheethanolto burn,and carbonizebygradual
solution, and connect the ‰ask to the distillation apparatus
heating.Cool,add1mLofsulfuricacid,heatcarefully,and
(Fig.1.08-1)washedbeforehandbypassingsteamthroughit.
incinerate by ignition between 5009C and 6009C. If a car-
Totheabsorption‰askKadd15mLofboricacidsolution(1
bonized substance remains,moisten with a smallamountof
in 25), 3 drops of bromocresol green-methyl red TS and
sulfuric acid, and incinerate by ignition. Cool, dissolve the
su‹cient water to immerse the lower end of the condenser
residue in 3mL of hydrochloric acid, evaporate on a water
tube J. Add 30mL of sodium hydroxide solution (2 in 5)
bathtodryness,wettheresiduewith3dropsofhydrochloric
throughthefunnelF,rinsecautiouslythefunnelwith10mL
acid, add 10mL of water, and dissolve by warming. Add 1
ofwater,immediatelyclosetheclampattachedtotherubber
dropofphenolphthaleinTS,addammoniaTSdropwiseuntil
tubingG,thenbeginthedistillationwithsteam,andcontinue
apaleredcolordevelops,thenadd2mLofdiluteaceticacid,
until the distillate measures 80 to 100mL. Remove the ab-
ˆlter if necessary, wash with 10mL of water, transfer the
sorption ‰ask from the lower end of the condenser tube J,
ˆltrateandthewashingtoaNesslertube,addwatertomake
JP XV General Tests / Qualitative Tests 2233
(3) Neutral solutions of acetates produce a red-brown
colorwithiron(III)chlorideTS,andared-brownprecipitate
whenboiled.Theprecipitatedissolvesandthecoloroftheso-
lutionchangestoyellowuponadditionofhydrochloricacid.
Aluminum salt
(1) Solutions of aluminum salts, when treated with am-
monium chloride TS and ammonia TS, yield a gelatinous,
whiteprecipitatewhichdoesnotdissolveinanexcessofam-
monia TS.
(2) Solutionsofaluminumsalts,whentreatedwithsodi-
umhydroxideTS,yieldagelatinous,whiteprecipitatewhich
dissolvesin an excessofthe reagent.
(3) Solutionsofaluminumsalts,whentreatedwithsodi-
umsulˆdeTS,yieldagelatinous,whiteprecipitatewhichdis-
solves in an excess of thereagent.
(4) AddammoniaTStosolutionsofaluminumsaltsuntil
agelatinous,whiteprecipitateisproduced.Thecolorofthe
precipitatechangestoreduponadditionof5dropsofaliza-
rin red S TS.
Ammonium salt
WhenheatedwithanexcessofsodiumhydroxideTS,am-
moniumsaltsevolvetheodorofammonia.Thisgaschanges
moistened red litmus paperto blue.
Antimony salt, primary
(1) Whenprimaryantimonysaltsaredissolvedinaslight
excessofhydrochloricacidforthetestandthendilutedwith
water, a white turbidity is produced. The mixture produces
anorangeprecipitateuponadditionof1to2dropsofsodium
sulˆdeTS.Whentheprecipitateisseparated,andsodiumsul-
ˆdeTSisaddedtooneportionoftheprecipitateandsodium
hydroxide TS is added to another portion, it dissolves in
either of these reagents.
(2) Add water to acidic solutions of primary antimony
saltsinhydrochloricaciduntilasmallquantityofprecipitate
is produced, and then add sodium thiosulfate TS: the
Fig. 1.08-1 precipitate dissolves. A red precipitate is reproduced when
the solution isheated.
rinsingtheendpartwithasmallquantityofwater,andtitrate Aromaticamines, primary
<2.50> the distillate with 0.005molWL sulfuric acid VS until Acidicsolutionsofprimaryaromaticamines,whencooled
the color of the solution changes from green through pale in ice,mixedwith3 drops ofsodiumnitriteTS underagita-
grayishbluetopalegrayishred-purple.Performablankde- tion,allowedtostandfor2minutes,mixedwellwith1mLof
termination in the same manner, and make any necessary ammoniumamidosulfateTS,allowedtostandfor1minute,
correction. and then mixed with 1mL of N,N-diethyl-N?-1-
naphtylethylenediamine oxalate TS, exhibit a red-purple
Each mL of0.005molWL sulfuric acid VS
color.
＝0.1401mg ofN
Arsenate
(1) Neutralsolutionsofarsenatesproducenoprecipitate
with1to2dropsofsodiumsulˆdeTS,butproduceayellow
1.09 Qualitative Tests precipitate with hydrochloric acid subsequently added. The
separated precipitate dissolves in ammonium carbonate TS.
(2) Neutral solutions of arsenates produce a dark red-
QualitativeTestsareappliedtotheidentiˆcationofdrugs
brown precipitate with silver nitrate TS. When dilute nitric
andaredonegenerallywithquantitiesof2to5mLofthetest
acidisaddedtooneportionofthesuspension,andammonia
solution.
TS is add to another portion, the precipitate dissolves in
Acetate either of these reagents.
(1) When warmed with diluted sulfric acid (1 in 2), (3) Neutral or ammonia alkaline solutions of arsenates
acetatesevolve theodor of acetic acid. produce with magnesia TS a white, crystalline precipitate,
(2) When an acetate is warmed with sulfuric acid and a which dissolves by addition of dilute hydrochloricacid.
small quantity of ethanol (95), the odor of ethyl acetate is
Arsenite
evolved.
(1) Acidic solutions of arsenites in hydrochloric acid
2244 Qualitative Tests / General Tests JP XV
produceayellowprecipitatewith1to2dropsofsodiumsul- added dropwise.
ˆde TS. When hydrochloric acid is added to one portion of
Bromate
theseparatedprecipitate,itdoesnotdissolve.When ammo-
(1) Acidicsolutionsofbromatesinnitricacidyieldwith2
nium carbonate TS is added to another portion, the
to3dropsofsilvernitrateTSawhite,crystallineprecipitate,
precipitatedissolves.
whichdissolvesuponheating.When1dropofsodiumnitrite
(2) Slightlyalkaline solutions of arsenitesproduce ayel-
TS is added to this solution, a pale yellow precipitate is
lowishwhiteprecipitatewithsilvernitrateTS.Whenammo-
produced.
niaTSisaddedtooneportionofthesuspension,anddilute
(2) Acidic solutions of bromates in nitric acid exhibit a
nitric acid is added to another portion, the precipitate dis-
yellow to red-brown color upon addition of 5 to 6 drops of
solvesin eitherofthese reagents.
sodiumnitriteTS.When1mLofchloroformisaddedtothe
(3) Slightly alkaline solutions of arsenites produce a
mixtureandshaken,thechloroformlayerexhibitsayellowto
greenprecipitatewithcopper(II)sulfateTS.Whenthesepa-
red-brown color.
rated precipitate is boiled with sodium hydroxide TS, it
changesto red-brown. Bromide
(1) Solutions of bromides yield a pale yellow precipitate
Barium salt
withsilvernitrateTS.Uponadditionofdilutenitricacidtoa
(1) WhentheFlameColorationTest(1)<1.04>isapplied
portion of the separated precipitate, it dose not dissolve.
to barium salts, a persistentyellow-green color develops.
Whenammoniasolution(28)isaddedtoanotherportionand
(2) Solutionsofbariumsaltsproducewithdilutesulfuric
shaken, the separated solution yields a white turbidity upon
acid a white precipitate,which doesnot dissolveupon addi-
acidifying with dilute nitricacid.
tion ofdilutenitric acid.
(2) Solutions of bromides exhibit a yellow-brown color
(3) Acidicsolutionsofbariumsaltsinaceticacidproduce
with chlorine TS. The mixture is separated into 2 portions.
a yellow precipitate with potassium chromate TS. The
Whenoneportionisshakenwithchloroform,thechloroform
precipitatedissolvesby addition ofdilute nitric acid.
layer exhibits a yellow-brown to red-brown color. When
Benzoate phenol is added to the other portion, a white precipitate is
(1) Concentratedsolutionsofbenzoatesproduceawhite, produced.
crysralline precipitate with dilute hydrochloric acid. The
Calcium salt
separated precipitate, washed with cold water and dried,
(1) WhentheFlameColorationTest(1)<1.04>isapplied
meltsbetween 1209C and 1249C <2.60>.
to calcium salts, a yellow-red color develops.
(2) Neutralsolutionsofbenzoatesproduceapaleyellow-
(2) Solutions of calcium salts yield a white precipitate
redprecipitateupondropwiseadditionofiron(III)chloride
with ammonium carbonateTS.
TS.Theprecipitatechangestowhiteonsubsequentaddition
(3) Solutions of calcium salts yield a white precipitate
of dilute hydrochloricacid.
with ammonium oxalate TS. The separated precipitate does
Bicarbonate not dissolve in dilute acetic acid, but dissolves in dilute
(1) Bicarbonates eŠervesce upon addition of dilute hydrochloric acid.
hydrochloric acid,generating agas, which produces awhite (4) Neutral solutions of calcium salts produce no
precipitateimmediately,whenpassedintocalciumhydroxide precipitate, when mixed with 10 drops of potassium chro-
TS (common with carbonates). mate TS and heated (discrimination from strontium salts).
(2) Solutionsofbicarbonatesproducenoprecipitatewith
Carbonate
magnesiumsulfateTS,butproduceawhiteprecipitatewhen
(1) Carbonates eŠervesce upon addition of dilute
boiled subsequently.
hydrochloric acid,generatinga gas,which producesa white
(3) A cold solution of bicarbonates remains unchanged
precipitateimmediately,whenpassedintocalciumhydroxide
orexhibitsonlyaslightlyred coloruponadditionof1drop
TS (common with bicarbonates).
of phenolphthalein TS (discrimination from carbonates).
(2) Solutionsofcarbonatesyieldwithmagnesiumsulfate
Bismuth salt TS awhite precipitate,whichdissolvesby additionofdilute
(1) Bismuth salts, dissolved in a slight excess of acetic acid.
hydrochloricacid,yieldawhiteturbidityupondilutionwith (3) Coldsolutionsofcarbonatesexhibitaredcolorwith1
water.Adarkbrownprecipitateisproducedwith1to2drops drop of phenolphthalein TS (discrimination from bicar-
of sodium sulˆde TS subsequently added. bonates).
(2) Acidicsolutionsofbismuthsaltsinhydrochloricacid
Ceric salt
exhibita yellow color upon addition of thiourea TS.
(1) Whenaceroussaltismixedwith2.5timesitsmassof
(3) Solutionofbismuthsaltsindilutenitricacidorindi-
lead(IV)oxide,nitricacidisaddedandthesolutionisboiled,
lute sulfuric acid yield with potassium iodide TS a black
it exhibits a yellow color.
precipitate,whichdissolvesinanexcessofthereagenttogive
(2) Solutions of cerous salts yield a yellow to red-brown
an orange-colored solution.
precipitate upon addition of hydrogen peroxide TS and
Borate ammonia TS.
(1) When ignite a mixture of a borate with sulfuric acid
Chlorate
and methanol,itburns with a green ‰ame.
(1) Solutionsofchloratesyield no precipitate with silver
(2) Turmericpaper,whenmoistenedwithacidicsolutions
nitrateTS.When2to3dropsofsodiumnitriteTSanddilute
of borates in hydrochloric acid and dried by warming, ex-
nitric acid are added to the mixture, a white precipitate is
hibits a red color, which changes to blue with ammonia TS
producedgradually,whichdissolvesbyadditionofammonia
JP XV General Tests / Qualitative Tests 2255
TS. the separated precipitate, it does not dissolve. When hot di-
(2) WhenindigocarmineTSisaddeddropwisetoneutral lute nitric acid is added to another portion, the precipitate
solutionsofchloratesuntilapalebluecolorappears,andthe dissolves.
mixture is acidiˆed with dilute sulfuric acid, the blue color
Cyanide
vanishespromptlyuponsubsequentdropwiseadditionofso-
(1) Solutionsofcyanidesyieldawhiteprecipitatewithan
diumhydrogensulˆte TS.
excessofsilvernitrateTS.Whendilutenitricacidisaddedto
Chloride a portion of the separated precipitate, it does not dissolve.
(1) Solution of chlorides evolve an odor of chlorine, When ammonia TS is added to another portion, the
whenmixedwithsulfuricacidandpotassiumpermanganate, precipitatedissolves.
and heated. The gas evolved turns moistened potassium (2) Solutions of cyanides yield a blue precipitate, when
iodide starch paperblue. mixedbyshakingwith2to3dropsofiron(II)sulfateTS,2
(2) Solutions of chlorides yield a white precipitate with to3dropsofdiluteiron(III)chlorideTSand1mLofsodium
silvernitrateTS.Whendilutenitricacidisaddedtoaportion hydroxide TS, and then acidiˆed with dilute sulfuric acid.
oftheseparatedprecipitate,itdoesnotdissolve.Whenanex-
Dichromate
cess of ammonia TS is added to another portion, the
(1) Solutions of dichromates exhibita yellow-red color.
precipitatedissolves.
(2) Solutionsofdichromatesproduceayellowprecipitate
Chromate with lead (II) acetate TS. When acetic acid (31) is added to
(1) Solutions of chromatesexhibit a yellow color. one portion of the suspension, the precipitate dose not dis-
(2) Solutions of chromates produce a yellow precipitate solve.Whendilutenitricacidisaddedtoanotherportion,the
withlead(II)acetateTS.Whenaceticacid(31)isaddedtoa precipitatedissolves.
portion of the suspension, the precipitate does not dissolve. (3) Whenacidicsolutionsofdichromatesinsulfuricacid
When dilute nitric acid is added to another portion, the aremixedwithanequalvolumeofethylacetateandwith1to
precipitatedissolves. 2dropsofhydrogenperoxideTS,shakenimmediatelyandal-
(3) When acidic solutions of chromates in sulfuric acid lowed to stand, the ethylacetate layer exhibits a blue color.
are mixed with an equal volume of ethyl acetate and 1 to 2
Ferric salt
dropsofhydrogenperoxideTS,shakenimmediatelyandal-
(1) Slightly acidic solutions of ferric salts yield with
lowed to stand,the ethyl acetate layerexhibits a bluecolor.
potassiumhexacyanoferrate(II)TSablueprecipitate,which
Citrate does not dissolve in dilute hydrochloric acid subsequently
(1) When20mLofamixtureofpyridineandaceticanhy- added.
dride (3:1) is added to 1 or 2 drops of a solution of citrate, (2) Solutions of ferric salts yield with sodium hydroxide
andthesolutionisallowedtostandfor2to3minutes,ared- TS a gelatinous, red-brown precipitate, which changes to
brown colordevelops. black upon addition of sodium sulˆde TS. The separated
(2) Neutral solutions of citrates, when mixed with an precipitate dissolves in dilute hydrochloric acid, yielding a
equalvolumeofdilutesulfuricacidandtwo-thirdsvolumeof whiteturbidity.
potassium permanganate TS, heated until the color of per- (3) Slightlyacidicsolutionsofferricsaltsexhibitapurple
manganateisdischarged,andthentreateddropwisewithbro- color with 5-sulfosalicylic acid TS.
mine TS to one-tenth of total volume, yield a white
Ferricyanide
precipitate.
(1) Solutions of ferricyanidesexhibit a yellow color.
(3) Neutralsolutionsofcitrates,whenboiledwithanex-
(2) Solutions of ferricyanides yield with iron (II) sulfate
cess of calcium chloride TS, yield a white crystalline
TS a blue precipitate, which does not dissolve in dilute
precipitate.WhensodiumhydroxideTSisaddedtoaportion
hydrochloric acid subsequently added.
oftheseparatedprecipitate,itdoesnotdissolve.Whendilute
hydrochloricacidisaddedtoanotherportion,theprecipitate Ferrocyanide
dissolves. (1) Solutions of ferrocyanides yield with iron (III) chlo-
ride TS a blue precipitate, which does not dissolve in dilute
Cupric salt
hydrochloric acid subsequently added.
(1) Whenawellpolishedironplateisimmersedinacidic
(2) Solutions of ferrocyanides yield with copper (II) sul-
solutions of cupric salts in hydrochloric acid, a red metallic
fate TS a red-brown precipitate, which does not dissolve in
ˆlm appearson itssurface.
dilute hydrochloric acid subsequently added.
(2) Solutions of cupric salts produce a pale blue
precipitate with a small quantity of ammonia TS. The Ferrous salt
precipitate dissolves in an excess of the reagent, yielding a (1) Slightly acidic solutions of ferrous salts yield with
deep blue-colored solution. potassiumhexacyanoferrate(III)TSablueprecipitate,which
(3) Solutionsofcupricsaltsyieldared-brownprecipitate does not dissolve in dilute hydrochloric acid subsequently
with potassiumhexacyanoferrate(II)TS.Whendilutenitric added.
acid is added to a portion of the suspension, the precipitate (2) Solutionsofferroussaltsyieldwithsodiumhydroxide
does not dissolve. When ammonia TS is added to another TS a greenish gray, gelatinous precipitate,which changesto
portion, the precipitate dissolves, yielding a deep blue- black with sodium sulˆde TS.Theseparated precipitatedis-
colored solution. solves in dilute hydrochloric acid.
(4) Solutions of cupric salts produce a black precipitate (3) Neutralorslightlyacidicsolutionsofferroussaltsex-
withsodiumsulˆdeTS.Whendilutehydrochloricacid,dilute hibit an intense red colorupon dropwise addition ofa solu-
sulfuricacidorsodiumhydroxideTSisaddedtoaportionof tion of 1,10-phenanthroline monohydrate in ethanol (95) (1
2266 Qualitative Tests / General Tests JP XV
in 50). withammoniumcarbonateTSawhiteprecipitate,whichdis-
solves in ammonium chloride TS. A white, crystalline
Fluoride
precipitateisreproducedbysubsequentadditionofdisodium
(1) When solutions of ‰uorides are heated with chromic
hydrogenphosphate TS.
acid-sulfuric acid TS, the inside of the test tube is not
(2) Solutions of magnesium salts yield with sodium
moistened uniformly.
hydroxideTSawhite,gelatinousprecipitate.WheniodineTS
(2) Neutralorslightlyacidicsolutionsof‰uoridesexhibit
isaddedtooneportionofthesuspension,theprecipitatede-
a blue-purple color after standing with 1.5mL of a mixture
velops a dark-brown color. When excess sodium hydroxide
of alizarin complexone TS, acetic acid-potassium acetate
TSisaddedtoanotherportion,theprecipitatedoesnotdis-
buŠersolution,pH 4.3, and cerium (III) nitrate TS (1:1:1).
solve.
Glycerophosphate
Manganese salt
(1) Solutionsofglycerophosphates remain unaŠected by
(1) Solutionsofmanganesesaltsyieldawhiteprecipitate
additionofcalciumchlorideTS,butyieldaprecipitatewhen
withammoniaTS.WhensilvernitrateTSisaddedtoapor-
boiled.
tion of the suspension, the precipitate changes to black.
(2) Solutions of glycerophosphates yield no precipitate
Whenanotherportionisallowedtostand,theupperpartof
with hexaammonium heptamolybdate TS in the cold, but
the precipitate exhibits a brownish color.
yield a yellow precipitate when boiled fora long time.
(2) Acidic solutions of manganese salts in dilute nitric
(3) When glycerophosphates are mixed with an equal
acidexhibitapurple-redcolorwithasmallquantityofpow-
mass of powdered potassium hydrogen sulfate and heated
dered bismuth sodium trioxide.
gently over a free ‰ame, the pungent odor of acrolein is
evolved. Mercuric salt
(1) A copper plate is immersed in solutions of mercuric
Iodide
salts, allowed to stand, taken out, and then washed with
(1) Solutionsofiodidesyieldayellowprecipitatewithsil-
water.Theplatebecomesbrightandsilverywhiteinappear-
vernitrateTS.Whendilutenitricacidisaddedtooneportion
ance, when rubbed with paper or cloth (common with mer-
ofthesuspension,andammoniasolution(28)toanotherpor-
curous salts).
tion, the precipitates do not dissolve in either of these rea-
(2) Solutionsofmercuricsaltsyieldwithasmallquantity
gents.
of sodium sulˆde TS a black precipitate, which dissolves in
(2) Acidic solutions of iodides exhibit a yellow-brown
anexcessofthereagent.Theblackprecipitateisreproduced
colorwith1to2dropsofsodiumnitriteTSandthenyielda
by subsequent addition of ammonium chloride TS.
black-purple precipitate. The solutions exhibit a deep blue
(3) WhenpotassiumiodideTSisaddeddropwisetoneu-
colorwith starch TS subsequently added.
tralsolutionsofmercuricsalts,aredprecipitateisproduced.
Lactate The precipitatedissolves in an excess ofthereagent.
Acidic solutions of lactates in sulfuric acid, when heated (4) Acidicsolutionsofmercuricsaltsinhydrochloricacid
withpotassiumpermanganateTS,evolvetheodorofacetal- yield with a small quantity of tin (II) chloride TS a white
dehyde. precipitate,whichchangestograyishblackuponadditionof
an excess of the reagent.
Lead salt
(1) Solutions of lead salts yield a white precipitate with Mercurous salt
dilutesulfuricacid.Whendilutenitricacidisaddedtoapor- (1) Acopperplateisimmersedinsolutionsofmercurous
tion of the separated precipitate, itdoes notdissolve.When salts, allowed to stand, taken out, and then washed with
sodium hydroxide TS is added to another portion and water.Theplatebecomesbrightandsilverywhiteinappear-
warmed,orwhenammoniumacetateTSisaddedtoanother ance, when rubbed with paper or cloth (common with mer-
portion, the precipitate dissolves. curic salts).
(2) Solutions of lead salts yield with sodium hydroxide (2) Mercurous salts or their solutions exhibit a black
TSawhiteprecipitate,whichdissolvesinanexcessofsodium color with sodium hydroxideTS.
hydroxideTS,andyieldsablackprecipitateuponsubsequent (3) Solutionsofmercuroussaltsyieldawhiteprecipitate
addition ofsodium sulˆde TS. with dilute hydrochloric acid. The separated precipitate
(3) Acidicsolutionsofleadsaltsindiluteaceticacidyield changesto black upon addition ofammonia TS.
withpotassiumchromateTSayellowprecipitate,whichdoes (4) Solutions of mercurous salts yield with potassium
not dissolve in ammonia TS but dissolves in sodium iodideTSayellowprecipitate,whichchangestogreen,when
hydroxide TS subsequently added. allowed to stand, and changes again to black upon subse-
quent addition ofan excessof the reagent.
Lithium salt
(1) WhentheFlameColoratuionTest(1)<1.04>isapplied Nitrate
to lithium salts, a persistentred color develops. (1) When a solution of nitrates is mixed with an equal
(2) Solutions of lithium salts yield with disodium volume of sulfuric acid, the mixture is cooled, and iron (II)
hydrogenphosphate TS a white precipitate, which dissolves sulfateTSissuperimposed,adarkbrownringisproducedat
upon subsequent addition ofdilute hydrochloric acid. the junction ofthetwo liquids.
(3) Solutionsoflithiumsaltsyieldnoprecipitatewithdi- (2) Solutions of nitrates exhibit a blue color with
lute sulfuric acid (discrimination from strontium salts). diphenylamine TS.
(3) WhenpotassiumpermanganateTSisaddedtoacidic
Magnesium salt
solutions of nitrates in sulfuric acid, the red-purplecolor of
(1) Solutions of magnesium salts yield upon warming
the reagent does notfade (discrimination from nitrites).