449
V O L U M E 20, NO. 5, M A Y 1 9 4 8 tilled water and adding aluminum sulfate to obtain a final pH of 4.5. Pet,roleuni ether extraction did not change the co~npositiori of t,he precipitate residue, even in the presence of a water phase. ii material of the composition of aluminum diresinate was isolated froni size precipitates and sized papers by prtroleum ether est~raction. Pet,roltwni ether wtrartioii of size precipitates prepawd from sizes of 0 tlJ 7Scc frw rosin lrft a residue of the approxi~nate composition of duniinum diresinate in earh case. The reaction AI-++ 3 RcsH 2 0 +AIIit~spOH4 HI& 4
+
+
+
and the free rosin rontent of tht, original sizes used can account for th(1 size prwipitatr. compositions obscJrved.
LITERATURE CITED (1) Bialkowaky, 1933).
H . K., Papcr T r a d t J.,97, No. 13, 29-46 (Sept. 2 8 ,
(2) Fieser, L. E., " E x p e r i m e n t s i n Organic Chemistry," pp. 350-9, B o s t o n , D. C. Heath a n d Co., 1935. (3) K e u g e h a u e r , E. L., Papier-Fabr.. 10, 1308--12 ( 1 9 1 2 ) . (4) P r i c e , D., I n d . Eng. Chem., 3 9 , 1143 ( 1 9 4 7 ) . (5) Price, D . . and Camei,on, D. D., P u l p P a p e r dIag. Can., 47, No. 3, 142-8 iConwiition Issue., 19461 : Pa,wer Trade J... 1 2 3 . No. 2 5 . ~
I
,
I
35-41 (Dee. 1 9 , 1 9 4 6 ) . (6) Hobinson, J.J., I h i d . , 103, No. i . 104-12 (Aug. 13, 1 9 3 6 ) . ( i )Srurlin, H., and Vandenberg. E. J.,Hercules Powder Po., u n p u b lished work. f X ) Tec-lr. X 9 h o r . P u l p and P a p e r Makers, Method T408-111-44.
KECBIVEDAugust 28, 1947. Presented before the Division of Cellulose Cheinistry a t t h e 111th hleeting of tlir . i \ I E R I C A S C H E M I C I L SOCIETY, Athntic C'ity, S . .J.
Quantitative Separation of Calcium, Barium, and Strontium SlLVE KALLRI WN, Lerloux & Co., 155 S i x t h Aae., New York, 4 niethod for the quantitathe separation of calcium, hariuni, antl strontium is exclusively based on the difference in soluhilitj of the chlorides of the three allialine earths in n-hut) 1 alcohol containing hydrogen chloride and i n h)drochloric acid containing n-biit)l alcohol. From the hutjl alcohol solution of the perchlorates of calcium, harium, and s t r o n good method. 1 t'oi, t h r s quantitative separation of ralriuni, baiium, and strontium from r m h other arc' c k >( ribed in the litri aturc. From the anhydi~oui:nitrates calciuni ma>-be extracted with ah.wlutc1 alwhol (12). or pix+~ably, with a mixture of (qual volumtzs of absolute alcohol and anhydrous ether (5,10) 01' with c*onct~ntr:itednitric acid (9). As these tiictthods are ba t~stizction,i~treatnitmtof thc filtered niti,atrs of barium antl,!or strontium, \vith intermittent solution in water, is r q u i r d in clc~alingwith l a r p r a n i ~ u n t sof the alkaline, earths. Far superior therrfore is the precipitation method ,suggt,stod t)>. \Yillarti and Goodspeed ( 1 3 ) in which harium and sti~ontiuni i i i ~ prt4pitnttd as nitratcs by the addition of roncentratcd nitt,ic:ic*itl. t o thv aqueous solution of the mixed nitrates. I3arium nitrate appctms to be practically insoluble in 7 6 5 nitric acid, :iffording a clean-cut separation from calcium. Strontium nit i x t c , beirig appreciably soluble in the 7 6 5 nitric acid, requii 8OC, : i d wiicrntration: this m c e d t a t w repreripitation of the s-trontiuni riitr,ate in dealing with more than 25 mg. of calcium. atisf:ictory are the methods for i;cpar:itinp barium arid
Table 1. Solubility of Barium Chloride in a 4 to 1 Mixture of 10.6 ,V HyJrochloric Acid and Ether in Presence of Strontium Chloriclt*at 20' C. H.,(-I
~
'l'liLe1, 61.0I h
0 .03J cr.0
,,,
. .
....
0.2482
~~~
Volu iiie
Esclu'ire of TTashings .1J1. 25 50 50 75 75 75 75 75 73 75
Error
Gram -0.0010 -0.0019 -0.0020 -0.0029 -0.0018 -0.0006 +0.0013 +0.0047 +0.0091 +0.0009
N. Y .
tium, a 20% solution of hjdrogen chloride in n-but:l alcohol (Willard and Smithreagent)precipitateschlorides of harium and strontium; calcium chloride is very soluble. From an aqueous solution of the chlorides of harium and strontium, a 4 to 1 mixture of 11.0 X h)drochloric acid and n-butyl alcohol precipitates barium but riot strontium chloride. strontium fi,om t:avh otht.1. T h r l'avorctl procedure consists in precipitating harium chromatt, at a pH of about 4.6 in a buffered acetic acid-acetatc solution. Iid of a 4 to 1 niixturts o f 10.6 .V hydrochloric acid and ethtxr (4)has scarcrly bren ci.iticall~.tfisrusscd in tht. literatures. This writer carried out a riuni1)c~i~ of tc (Tai)lc I), but \\-as unable to confirm the findiiigs o t (;ooch antl Soderman, ivho olaini that their nirathotl :iffoi,(ts i i rl~~:~ii-cut ity:wation of thc! tivo alkaline earths. I n the first place, thr solubilit>-of 1)ai.iuni c~hloi~icte appears to tic, considwably givater than can bi, gathered floni the data subniittcd hy the authors (.$), \Tho stsitti that the soluhility of bmiuni chlorid(. in 75 ml. of n 4 to 1 mixture of 33"; (10.6 S)hydrocmhloric acid and cxthc.r at 20" (', amounts to l(w than 0.5 mg. I I a r (L7), o n thts oththr hand, ha> shown that thr, solubility of barium chloride i n a 1 to 1 mixtuw o f concent~.iitid(12.0 S ) hydrorhloi,ic~acid arid ethct. at 20" ('. aniwnts to apprbsiniattxly 1.3 mg. of barium chloi.idc1 ptsi' 100 nil. of solution arid statw +hat the "solubility illcrc,ases ~ ( ~ I . ? .,.allidly n-ith tllc diIninuation in strength of acid." From thv data in Table I it would appear that the solubility of barium c*hloiidr in a 4 t o 1 mixture of 10.0 .\- hydrochloric acid and ethc>ramounts to about 4 m e . per 100 nil. of solution, antl that a niarktd tt~ndcncytoward coprecipitntion of sti~>ntiunichloride with the hxrium chloride may offset part or all of the solubility 1ossc.s of the baiium chloride or may even cituv high bariuni rtLsults. F I L L A R D A K D SMITH KE.4GENT
I n earlier papers (6, 7 , 14) the effrct, of a 20% solution of hydrogen chloride in n-butyl alcohol (Willard and Smith reagent)
ANALYTICAL CHEMISTRY
450
u p m the butyl :ilcohol solution of ttiix p-drochloric acid art' added 40 nil, of watw. The solutiort is cooltd to ht,low 20" C. anti 120 ml. of n-butyl alcohol are added. Reagents Used in Experiments. Barium rhloride frce from calcium and strontium n-as prepared by dissolving thc reagent grade palt, in Tratcsr arid precipitating the barium chloridt. viith rthagent 4. tt' i r , c ~from calcium, barium, and alkali metals diwdvirig the reagent-grade salt, which contairird Icsx than 0.005c; barium hut approximately 0.1 % of calcium and 0 . 5 5 alkali nietais, in \vater and precipitating the strontium nitratc, b y the addition of concentrated nitric acid ( I S ) . '1 solution of c:tlcium c*hloride was prepared by acidifying reagxit-grade calcium mrhonate, of very high purity, n-ith Iivdrochloric acid.
the weight of the mixed chlorides is less than 250 mg., containing less than 125 nig. of strontium chloride, only half the amount of water, acid, and alcohol should be used.) Decant the clear supernatant liquid through a weighed Gooch crucible (the one held from the previous operation may be used), receiving the filtrate directly into a 150-ml. beaker, transfer tht. barium chloride ont,o the crucible, police the beaker, and wash the cruci1)le five to eight times with 1- to 2-ml. portions of reagent, 4. Place the crucible on a small cover glass, dry for 1 hour at 110" C., and finally in a muffle for 15 minutes a t 350" C. Cool in a desiccator and twigh as anhydrous barium chloride. This weight should he corrected in accordance with the dat,a presented in Table 111. The solubility of barium chloride in 75 nil. of the n-ater, acid, and alcohol mist'ury amounts to 2.0 mg. This solubility of barium chloride, hon-ever, is partly compensatrd by coprecipitation of strontium chloride. Therefore, for amounts of barium chloride up to 50 mg., add 2.0 nig., irrespective of thc amount of strontium chloride present (up to the limit of 250 nig.). For amounts of barium chloride from 50 to 150 mg., add 2.0 mg. minus 0.4 nig. for every 100 nig. of strontium chloride present. For amounts of barium chloride from 1.50 t o 500 nig., add 2.0 mg. minus 0.6 nig. for every 100 mg. of strontium chloride present.
5
-
4
-t $ 3.5 I
0
5 3 0
51 P.5 t
f
P
PROCEDURE
Separation of Barium and Strontium from Calcium. Add 5 ml. of perchloric acid to the nitric or hydrochloric acid solution of calcium, barium, and strontium, contained in a 50-ml. beaker, a n d evaporate t o dryness on a hot plate a t a temperature>not ovet 180" C. Cool, add 10 ml. of n-butyl alcohol, and heat with intermittent a g h t i o n just to boiling. ,4 clear solution should result. Immediately add 10 ml. of the Willard and Smith reagent, the first 2 ml. dropnise, and continue the boiling for about a minute to facilitate the formation of a coarse crystalline precipitate. [Inasmuch as the solubility of strontium chloride in a 10% solutic.n of hydrogen chlcride must, not be neglected (see Figure 1) smaller amounts of butyl alcohol and Killard and Smit'h reagent should be used \Thenever feasible, particularly when dealing witti small quantities of the alkaline earths.] Digwt at,about5O0C.forabout15 minutes, cool to below20" C., and decant the supernatant liquid into a dry but, umreighed Goorh crucible, arranging the filtering apparatus so that the filtrate can be directly caught in a 250-ml. beaker. Transfer the precipitate to the Gooch crucible, police the beaker, and wash the crucible five tmoeight t,imes with 1-ml. portions of the 10ycsolution of hvdrOgen chloride in butyl alrohol. Reserve the filtrates for the determination of calcium. Dry the Gooch crucible for 1 hour a t 110' C., and finally for 15 minutes in a muffle a t 350" C. Cool in a desiccator and weigh. Dissolve the mixed chlorides of barium and strontium in a small amount of hot wat,er, receiving the filtrate and washings directly in a 100-ml. beaker. Dry the crucible for 1 hour at 110' C., cool, and weigh. The loss in weight represents the combined chlorides, of barium and strontium. (The Gooch crucible, after ignition over a free flame, may be held for the subsequent separation of barium and strontium.) Determination of Barium. Evaporate the solution of the mixed chlorides t.o dryness. Dissolve in 5.0 ml. of warm water (50" to 60" C.), then add with constant stirring 55 ml. of concentrated (12.0 JV)hydrochloric acid and 15 ml. of n-butyl alcohol. \\-arm to about 75 C., then cool t,o below 20' C. (The quantities of water, acid, and alcohol specified are intended for amounts of mixed chlorides not exceeding 500 mg. and containing not. more than 250 mg. of strontium chloride. When
P 4 6 a 1 0 1 ~ 1 4% Concentration o f Hydrogen Chloride in Butyl Alcohol
Figure 1. Solubility of Barium Chloride and Strontium Chloride in n-Butyl .~lc~ohol Containing Willard and Smith Reagent at 20° C. Determination of Strontium. Strontium chloride may be calculated by ( l i "t3rence from thc w i g h t of the mixed chlorides, but for grrattxi, wvcuracy it can hcb tlasily determined with little extra work. Evaporate the filtrate from the barium chloride to a small volume, transfer to a 50-ml. beaker, and evaporate to dryness. Add 5 ml. of water, 1 ml. of nitric acid, and 3 ml. of perchloric acid and evaporatca to complete dryness on a hot plate a t a temperature not, higher than 180" C. To t,lirI cold strontium perchlorate add just sufficient n-butyl alcohol to cause complete solution when heated t o boiling; 5 ml. of the alcohol should be ample for most Lrork. To tile boiling solution add an equal volume of the Willard and Smith reagent, the first 2 ml. dropwise, and continue the boiling for about. 0.5 minute to facilitate formation of a coarse crystalline precipitate. Cool to below 15' C., and filter on a dry t,ared Gooch crucible, policing the beaker and xashing the crucible twice with 1-ml. portions of 107, hydrogen chloride in n-butyl alcohol. Dry the Gooch crucible for 1 hour a t 110" C., t,hen for 15 minutes at, 350" C., and weigh as anhydrous strontium chloride after cooling in a desiccator. Correct this apparent weight of stront,ium chloride for the solubility of barium chloride in the hydrochloric acid-butyl alcohol mixture and for the coprecipitation of st,rontium chloride, in accordance with the instructions given above.
451
V O L U M E 20, NO. 5, M A Y 1 9 4 8 'I'nl)le
11.
Separation of Bariulli and Stronti~rni from Calcium
H ~ C I ~ s~C12 Taken Taken Gram Giam 0.0210
0.0421
....
0.0188 0,0754 0 0019 0 0188 0 0754
....
0.1884
0,2104
0.0154
0.2104 n.2104
0.2104 0.2104 0.2101 0.4208
....
0.1884 0.1884
0.1884
n . 1884
0.3768
CaCh Takrn Gram 0 1250 0 2800 0 .io00
BaCh idus SrCIz Found Gram 0,0211 0.0418 0 0424 6 :0606
0.1254 0.2497
-0.OOOR
0,2407 0.2506 0,2505
- 0.00ox - 0.0002
n.2103
-0.0005 - 0 . no04 - 0.0001
0,0014 0.0183 0.0760
0 r,OOO 0 7500 1 oonn 0 0500
0.1881 n ,2853 n ,3982 n , 3986 0.3090 0 3990 0 7080
0 2500 0 2.500 0 2500
1-0.0001 - 0.0003 + O ,0003
0.1173
om o
0 2.500 0 2,500
CaO Found Eqriivalent t o CaCln Gram
Error Gram
-0.0003 - 0.0003 - 0.0006 - 0.0002 +n ,0002
~0.0011
+o.ono4
0 . A008
0.2498
0.2502 0.250.5 0.0003 0,5000 0.7407 0.9979 0.0498
Tahle 111. Separation of' Hariurii from Stroiitiirni VOlIl1111'
Taken Gram 0 0210. 0 0421 0 2104 n 2104 0 4208 0 0421 n 0421 0 oz21
o
0842 0 0842 0 0842
0.1684 0,1684 0.1R84 0.2104 0.2104 0 2104 n 4208
SrCi9
Taken Gram
Baa, Found
Gram 0.0200
0.07a4 0.1884 0,2826 0,0754
0,1884
0.2826 0.0754
0 ,1884 0.2826 0.0754 0,1884 0,2826
0.07.54
0.0412 0 2084 n ,2085 0.4188 0 0410
0.0402 0.0408 0,0826 0.0830
0,0835
0.1670 0.1673 0.1680 0.2086 0,2093 0.2100 0.4190
Bar12 Corrected Gram 0.0210 0.0422 0.2104 0.2105 0.4208 n ,0420
0.0422 0,0428 0.0843 0.0843 0.0844
0.16m 0.1884 0,1683 n.2102 0.2102
0.2103 0.4214
JrClr Found Gram 0.0008 0 0008
o . on18
SrClz of PreCorrected cipitant Gram .If1 38 38
.... .,..
0,0020 0,0022 0,0766
0,0002 0.0756 0.1883
0.1903 0,2835 0.0768 0.1897 0.2888 0.0768 0,1890 0.2825
n o m
0 , 1802 0.2828 0,0764
0.2819 0.0751
'
0.1884 0.2824 0,0752 0.1881 0,2822
0,0763 n 1883
0.282:
n . 0740
75 75 7 .?I
38 75 73 7A 75 75 75 I-
I O
75
7:
-I .I I .a
Determination of Calcium. Ttir. filtratv from t h e rti~ontiurn chloridr may contain trams, but sr~ldonimore that1 0.1 t o 0.3 mg. of calcium chloride, which niay h a w ( prd the f h t sqJarat ion of calcium from barium and strontiuni. For r s t r c m t ~accuracy, it should therefore be romtincd with the solution cwitaining i h c bulk of thc calcium. Dilute the butyl alcohol-hydrugeri chloride sulutioii coni aining calcium with one third its volume of water and evaporate on water bath in such a way as t'o avoid condensation on the upper part of t.he beaker ( 6 , rj. When completely dry (prolonged heating should be avoided), add 10 ml. of water, 2 ml. of nitric arid, and 10 ml. of perchloric acid. Fume until fumes of perchloric acid escape. Cool and dilute wit,h water. In the absence of elements of the R?O, group precipitate the calcium in the usual way as oxalate, weighing it finally as the oxide or determining i t volumetrically with potassium permanganate. In the presence of interfering elements, use separations described in standard analytical textbooks ( 6 , I I ) . the, the,
ianic' nicdium is much greatw, and ininimuni soluhili ty is appronc8ht.d only when the concentration of the hydrogen chloride is illcreased to 1070. Thcwfore, a 10% solution of hydrogen chloride in butyl alcohol has bccv used throughout this work. h solubility of 2.2 mg. of strontium chloride in 100 ml. of the loc); solution of hydrogen chloride in tiutyl alcohol may scem prohibitive for quantitative analysis. H o w w r , 20 nil. is the maximum quantity of solution requirrad, cwlusive of washings, even in operating upon a mixture of 0.3 gram of rach of the thrve alkaline earths. Even smallcr volumes may be used n-ith ininor quantities of the three elements. Separation of Barium and Strontium from Calcium. Mixtures of knonn quantitics of the alkaline earths werc funicd to dryness with an exccss of perchloric acid and sabjccted t o thc rccomn ~ t ~ n dprocedure ~d for the separation of barium and strontium t'i.oni calcium. The resulting data, prwvnttd iii Tahle 11, iri(1ii:nto that the proposcd nit,thod affords a complete srpai~ation o f t l i r s two alkaline earths from calcium. This should pruvc>a n 11 ttractive ftsature not found in the carlior csstraction metfiwls. #;vtw the cscellcnt precipitation method of Yillard and Goodspcetl (f3)requires reti,eatnient, of thc strontium salt in chiling with more than 25 m g . of calcium. Separation of Barium from Strontium. Mixtures of k i i o n . ~ qu:~i:titiesof barium and str-a limit:d number O t c-l(~nitwts intcrfere with the mothod dcsc*ii!ietlin this p:ipei,. Sijdiuni. potassium, arid large amounts of ammonium salts \Iiould be absent. They niay tic reniowd hy precipitating the carbonate, f o l l o w d hy their :~lli:~linc earths with arii~iio~iiuni i~oiivc~ision into the pcwhloi~atcs. Small :mounts of potassium, rvmovcd as ptwhlorate from the butyl liut not sodium, niay :Llfv)hoI S O ~ U t i f J l l prior t o ~dditioii of thr \T-ilhrd nntl Smith I Y % ent. 'h, sulfates ion should ti(%:it)s(-tit. Ji'hvii tlt,ulinp nith :i niist UT'(' of the sulfatcxs of the alkaline earths, prcxliniinary steps would iiiv(~Ivef'usion of the saniplo with potassium carhoii:itc7, solution o i the filtercti and n-ashed carbonates iii hJ-drochloric. avid, prec.ipitation x i t h aninioniuni carbonate, :itid conversion ot t,hc filtcwd nnd \vashed caihmates into perchloi~:itcs: o r the amiiioiiium carbonate separation may bc omittid ntitl xriy potassium, prior rt.tained by the alkaline wrths, he removctl :IS pc~r~rhloratc~ to addition of the JVillard ant1 Smith rc'agent. Lclad Phoulti be absent antl may b(: i~ciiiovcd1). ])i~t~ipitntiurr with hydrogen sulfide in a nonoxidizing dilute hyclrochloric acid i n a nitric :ic.irl .solution. solution, or preferably, b ~rlwtvol 1 x 3
LITER i T U H E CITH) EXPERIMENTAL
Solubility of Barium and Strontium Chlorides. To determine the solubility of barium chloride and strontium chloride in varying concentrations of the Willard and Smith reagent, measured quantities of barium chloride and st,rontium nitrate were fumed to tllyncss with an excess of perchloric acid. To the dry salts m e a s u i d amounts of butyl alcohol were added, the solutions heatcd to boiling, and t'he barium and strontium precipitated as chlorides I)? the addition of varying measured amounts of the Willard and Smith reagent. .Ifter cooling, t h r solutions mere filtered t,hrough Gooch crucibles and evaporated t o dryness on the water bath with the usual precautions, and after fuming wit,h nitric and sulfuric acids, barium and st,rontiuin were determ i n d as the sulfates. The resulting data are presented i n Figure 1.
'
It is apparent that the solubility of barium chloride in the 5 to G% so1ut)ionof hydrogen'chloride in butyl alcohol, used in earlier work for the determination of the alkali metals, is very small. On the other hand, the solubility of strontium chloride in the
1 1 Beyel ntid I&iiiitti, Isu. l,:s(;.CHKM... \ L \ I . , I:o.. 19, 35-7 (1947). ( 2 1 Fresenius, Z.anal. Chem., 29,41B (1890). i:3' Zbid., 32, 189 (1893). ( 4 1 Gooch and Soderman. Am. .I. Sci.,, 46, 538-4U (1918). i 61 Hillebmrid and Lundell. ";\ppiied Inoi,ganic - i i d y h i s , " u p . 4934 , Kew York, John ITiley & Sons, 1929. Ilil Kallinann, IN).I
