Tennessee Valley A nth o Fertilizer Worka
Library
INDUSTRIAL a n d ENGINEERING CHEMISTRY
ANALYTICAL E D IT IO N
H A R R IS O N E. H O W E , E D IT O R ISSU ED F E B R U A R Y 15, 1941 V O L. 13, N O . 2 C O N S E C U T IV E N O . 4
O r g a n ic H a lo g e n C o m p o u n d s i n M in e r a l O ils . . . M. S. Agruss, G eorge W. Ayers, Jr., and Hans Schindler N o te o n D e t e r m i n a t i o n of S ilic a i n C a lc in e d A lu m i n a ... J. E. Edwards R a p id M e t h o d f o r D e t e r m in i n g F e r r ic a n d F e r r o u s
I r o n ...John O. Percival V o lu m e tr ic D e t e r m i n a t i o n of I r o n a n d A l u m in u m
i n C e m e n t w i t h 8 -H y d r o x y g u in o lin e . Leo Kampf S p e c tr o p h o t o m e t r ic a n d B io lo g ic a l A ssa y o f V ita m i n A i n O i l s ...
N. H. Coy, H. L. Sassaman, and Archie Black P o la r o g r a p h ie D e t e r m i n a t i o n o f N ic k e l a n d C o b a lt James J. Lingane and Herbert Kerlinger C o lo r im e tr ic D e t e r m i n a t i o n o f P h o s p h o r u s i n I r o n O r e ...Hobart H. Willard and E. John Center B a s ic S u l f a te s o f I r o n a n d A l u m in u m i n A n a ly tic a l
S e p a r a t i o n s ...J- G. Fairchild B io m e tr y i n S e rv ic e o f B io lo g ic a l A ssay . C. I. Bliss D e t e r m i n a t i o n o f S ilic o n i n M o n e l M e ta l, C o p p e r- S ilic o n A llo y s, E t c ... Frederick B. Clardy, Herman E. Maupin, and R. Stevens Gibbs D e t e r m i n a t i o n o f A s c o rb ic A cid i n C i tr u s F r u i t
J u i c e s ...Robert Ballentine D e t e r m i n a t i o n o f B r o m in e A d d itio n N u m b e r . . . Karl Uhrig and Harry Levin A l i q u a n t S a m p le s i n D e t e r m in a t io n of F lu o r id e s i n
M ix e d F o o d s ... Edward J. Largent D e t e r m i n a t i o n o f I r o n b y Z i m m e r m a n - R e i n h a r d t
M e t h o d ...William R. Crowell, W ayne W. Luke, and Thomas G. Mastin D i s t i ll a ti o n o f F o a m in g S o lu tio n s u n d e r V a c u u m . Dean R. Rexford N ew C o lo r R e a c ti o n s f o r C a n n a b i s s a tiv a R e s in . . William John Blackie D e t e r m i n a t i o n o f A c e ty l G r o u p ...
John R. Matchett and Joseph Levine M in e r a l A n a ly s is o f B io lo g ic a l M a t e r i a l s . . . . ■
Mary A. Griggs, Ruth Johnstin, and Bonnie E. Elledge D e t e r m i n a t i o n o f M e ta ls i n S o m e P e c ti n a te s . . - Phyllis Ambler and Mary A. Griggs
69 70
71v L /"
72
74 77 81 83 84
88 89 90 93
94 95 96 98 99 102
U se o f T h o r i u m N i t r a t e t o D i s t i n g u is h b e tw e e n P e c ti n a n d C e r ta i n G u m s ...E. F. Bryant 103 D e t e r m i n a t i o n o f O x y g e n i n T a n k H y d r o g e n . . .
H ubert N. Alyea 104 T u n g s te n - N ic k e l a n d T u n g s t e n - S il v e r E le c tr o d e
S y s te m s i n N e u t r a l i z a t i o n s ...
Harold G. Dietrich and Paul J. Bender 10S E x tr a c t i o n a n d D e t e r m i n a t i o n o f P y r e t h r i n I i n
G r o u n d P y r e t h r u m F lo w e rs . . . . Jethro S. Yip 107 N ew P h o t o e le c tr i c F l u o r i m e t e r a n d S o m e A p p lic a
t i o n s ...Frederick Kavanagh 108 H y d r o m e te r f o r T u r p e n t i n e I n d i c a t i n g P o u n d s p e r
G a l l o n ...W. C. Smith 112 R a p id M e th o d f o r C a li b r a ti o n o f F lo w m e te r s . . .
Herman J. Meuron 114 C a r b o n 'T r a i n f o r C o n tr o l A n a l y s i s ...
Louis Singer, Howard J. Stark, and John A. Krynitsky 115 S im p le T e s ts t o I n d i c a t e C o n d i ti o n o f A n a ly tic a l
B a l a n c e ... Leonard C. Kreider 117 U s e f u l C e n tr if u g e A c c e s s o r ie s ...
C. R. Johnson and Harvey Miller 118 U lt r a v i o l e t P h o t o m e t e r ...V. F. Hanson 119 S im p ly C o n s t r u c te d C o lo r C o m p a r a t o r ...
Richard H. Wilhelm 123 M IC R O C H E M IS T R Y
D e t e r m i n a t i o n o f C o p p e r i n P l a n t M a te r ia ls U s in g D r o p p in g M e r c u r y E l e c t r o d e ...
J. Fielding Reed and Ralph W. Cummings 124 S y s te m a t i c Q u a l it a ti v e O r g a n ic M ic r o a n a ly s is . .
William G. Batt and Herbert K. Alber 127 P r e s s u r e R e g u la t o r f o r M i c r o d e t e r m i n a t i o n of
C a r b o n a n d H y d r o g e n ...John E. Vance 132 S e m im ic r o - a n d M ic r o - K je ld a h l S t e a m - D i s t i ll a -
t i o n U n i t ...J. H. Brant and D. C. Sievers 133 M O D E R N L A B O R A T O R IE S
M c G ilv re y H a ll a t K e n t S t a t e U n iv e r s ity . . . . C. F. Rumold 134
T h e A m e ric a n C h e ^ a , S o , e t „ c s n o r e s p o n d « * fo r th e a U te -n e n U a n d o p i n i ^ ^ d b y 25 ,8 0 0 copies of th is issu e p rin te d .
P u b l i c a t i o n O ffic e s E a s t o n , P e n n a .
E d i t o r i a l O f f ic e ; R o o m 7 0 6 , M i l l * B u i l d i n g , W a s h i n g t o n , D . C . T e l e p h o n e : N a t i o n a l 0 8 4 8 . C a b l e i J i e c h e m ( W a s h i n g t o n )
P u b lis h e d b y th e A m e ric a n C h em ica l S o cie ty , P u b lic a tio n Office, 2 0 th &
N o r th a m p to n S ts ., E a s to n , P e n n a . E n te r e d as seco n d -class m a tte r a t tn e P o s t Office a t E a s to n . P e n n a ., u n d e r th e A c t of M a rc h 3, 1879, *■* 5ui^
y e a r. I n d u s tr ia l E d itio n m o n th ly o n th e 1 st; A n a ly tic a l E d itio n m o n th ly o n th e 1 5 th . A c c e p ta n c e fo r m a ilin g a t sp ecial r a t e of p o s ta g e p ro v id e d to r in S ectio n 1103, A c t of O c to b e r 3 , 1917, a u th o r iz e d J u ly 13, 1918.
A n n u a l s u b s c rip tio n r a te , In d u s t r i a l Ed i t i o na n d An a l y t i c a l Ed i t i o n
so ld o n ly a s a u n it, m e m b e rs $3.00, o th e rs $4.00. F o re ig n p o sta g e ^to c o u n trie s n o t in th e P a n A m e ric a n U n io n , $ 2 .2 5 ; C a n a d ia n p o sta g e , $0.*o.
A d v e r t i s i n g D e p a r t m e n t : 3 3 2 W e s t 4 2 n d S t r e e t , N e w Y o r k , N . Y . T e l e p h o n e : B r y a n t 9 - 4 4 3 0
S in g le co p ies: I n d u s tr ia l E d itio n , $0.75; A n a ly tic a l E d itio n , $0.50. S p ecial
r a t e s to m e m b ers. . . ,
N o c la im s c a n b e allo w ed fo r copies of jo u r n a ls lo s t in th e m a ils u n le ss su c h claim s a r e rece iv ed w ith in 60 d a y s of th e d a t e of i33ue, a n d n o claim s w ill b e allo w ed fo r issu es lo s t as a r e s u lt of in su ffic ie n t n o tic e of c h a n g e of ad d re ss. (T e n d a y s ’ a d v a n c e n o tic e re q u ire d .) “ M issin g fro m files”
c a n n o t b e a c c e p te d as th e re a s o n fo r h o n o rin g a claim . A d d re s s c la im s to C h a rle s L . P a rs o n s , B u sin ess M a n a g e r, M ills B u ild in g , W a sh in g to n , D . C ., U. S. A.
4 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 13, No. 2
CENCO-COOLEY INDEXER FURNACE
Crucible Front
C r u c i b l e !
H E A R T H R O T A T E S
N o m o r e s in g e d h a n d s a n d s c r a m b le d c ru c ib le s to re m o v e c ru c ib le s fr o m th i s f u r n a c e . A n y c r u c ib le in t h e h e a ti n g c h a m b e r c a n b e b r o u g h t t o t h e d o o r b y t u r n i n g t h e n u m b e r e d in d e x in g w h e e l. T h e m u ffle is c y li n d r ic a l a n d t h e c ir c u la r h e a r t h r o t a t e s w i th t h e t u r n i n g o f t h e in d e x e r w h e e l. T h is d e s ig n n o t o n ly e lim in a te s a w k w a r d n e s s in h a n d li n g w o r k to a n d fro m th e h e a t i n g c h a m b e r , b u t g iv e s m o r e u n if o r m t e m p e r a t u r e d is t r i b u t i o n a n d 2 0% g r e a t e r c ru c ib le c a p a c i t y t h a n t h a t o f u s u a l m u ffle f u r n a c e s o f c o r r e s p o n d in g d im e n s io n s . T h e p y r o m e te r th e r m o c o u p l e e n te r s t h e c h a m b e r a b o v e t h e c e n te r o f t h e h e a r t h , a n d , w h e n e x a c t d e t e r m i n a ti o n s o f te c h n i c a l c h a r a c t e r i s ti c s o f m a t e r i a ls u n d e r t e m p e r a t u r e a r e t o b e m a d e , t h e th e r m o c o u p le c a n b e lo w e re d u n t i l in i n t i m a t e c o n t a c t w i t h t h e w o r k to
r e g i s te r i t s e x a c t t e m p e r a t u r e a t a ll tim e s . T h e p y r o m e t e r h a s a d o u b le sc a le c a l i b r a t e d t o 1 1 0 0° C e n ti g r a d e a n d 2 0 0 0 ° F a h r e n h e i t.
F o r 115 v o lts , A .C . o r D .C ., w i t h a p o w e r c o n s u m p ti o n o f a p p r o x i m a t e ly 1300 w a tt s . D im e n sio n s , o v e r a ll: H e ig h t, 15 in c h e s : w i d th , I8V4
i n c h e s ; d e p th , 1 6 l/ 2 in c h e s . M u ffle s p a c e : H e i g h t, 3 in c h e s ; d ia m e te r , 7 in c h e s . W i d t h o f d o o r, 41/ 2 in c h e s .
13615
C E N C O -C O O L E Y IN D E X E R F U R N A C E w i t h R h e o s t a t a n d P y r o m e t e r
$127.50
I n t e r i o r V iew o f N o . 13643 F u r n a c e
S C I E N T I F I C F p M f r i L A B O R A T O R Y
I NS TRUME NTS A P P A R A T U S
N e w Y o rk • Boston * C H I C A G O • To ro n to • San F ra n c isc o 13615
February 15, 1941 A N A L Y T I C A L E D I T I O N
n w w i m w p -
rJ M n e
B y a strange co in ci
d e n c e b o th P y rex b ra n d L ab oratory W are a n d V y c o r
brand Glassware were born in war tim e. "Pyrex” ware was introd uced shortly after the out
break o f W orld War I— "Vycor ware ju st before the present war began. B oth are products of Corning Research in Glass.
T ogether w ith the new Pyrex brand F ritted Glassware, re
c e n tly a n n o u n c e d , they h elp to assure the co n tin u ed in d e p e n d e n c e o f t h e A m erican Laboratory
Today in d u stries, hospitals and sch ools can pursue their laboratory work un deterred, confident that, because o f Corn
in g R esearch and C orning fa cil
ities, a ready supp ly o f labora
tory glassware w ill always be available.
“P Y R E X ” is a registered trade-mark and indicates manufacture by
C O R N I N G GX. A S S W O R K S • C O R N I N G , N . Y .
U ntil th e ch em ist Priestley su g g e ste d in 1770 th a t c a o u tc h o u c be used to erase pencil m arks, th e elastic su b stan ce n ow k n o w n as ru b b e r w as regarded m erely as a stran g e an d useless article. Seventy years later G o o d y e a r discovered th e process o f v u lcan izatio n , an d laid th e fo u n d a tio n o f th e m o d ern ru b b e r ind u stry .
T o d a y m o re th a n 30,000 different a rti
cles ate m a d e w holly or in p a rt o f ru b b er, an d new uses are regularly d ev elo p e d . A, b rie f trip th ro u g h th e M erck p la n t dis-
M E R C K & C O . I n c . N ew Y o rk • P h ilad elp h ia
closes m any form s o f ru b b er em p lo y ed in various o p eratio n s —visual evidence o f th e c o n trib u tio n s m ade to the chem ical in d ustry by th e ru b b er chem ist.
Likew ise, a v isito r to th e lab o rato ry o f a progressive ru b b e r ch em ist will n o te th e m any R eag en t C hem icals b earin g th e M erck lab el— p r o o f th a t M erck has k e p t pace by su p p ly in g th e chem icals essential for th e d e v e lo p m e n t o f new us<£ for, an d new form s of, a su b sta n c e o n ce regarded m erely as a curiosity.
M E R C K R E A G E N T S
U SE D BY THE
RUBBER C H E M I S T S
A c e to n e M e rc k R e a g e n t B arium C h lo r id e R e a g e n t C h lo ro fo rm R e a g e n t
B ro m in e R e a g e n t S o d iu m P e r o x id e R e a g e n t T h e q u a l ity of M e rc k M in e ra l A c id s a n d A m m o n ia W a te r is in k e e p in g w ith th a t of M e rc k R e a g e n t C h em ica ls.
a n u f a c fu r h iy C / c it i i.i f.i R A H W A Y , N . J.
St. Louis • in Canada: M erck & C o. L td., M o n treal and T o ro n to I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 13, No. 2
India rubber manufacturing on the banks of the Madeira River, 1875.
Before the era of the great Rubber plantations, native Indians undertook the great trouble of penetrating the Virgin forests to collect the latex. Re
turning to their modest huts they started to transform it into raw rub
ber. They poured the liquor over a stick turned slowly over a fire so that a ball of raw rubber was formed.
February 15, 1941 A N A L Y T I C A L E D I T I O N 7
Type M U 5 5 Muffle Fur
nace at the California
^
Institute of Technol- ogy, PasadenaLABORATORY FURN ACES
MULTIPLE UNIT
E L E C T R IC EXCLU SIV ELYREG. U. S PAT. OFF.
M I L W A U K E E . W I S C O N S I N
S E T T I N G T H E P A C E I N C H E M I C A L P U R I T Y S I N C E 1 8 8 2 * T ^
X I
TW K xuLajew T
B a k e r & A d a m so n
D iv is io n of G E N E R A I C H E M I C A L C O M P A N Y , 4 0 R e c to r S t., N « w Y o rk C . H A r c i c f s S a l ti O ffices: A tlan ta • B altim ore • Boston • Buffalo . C harlotte (N . C.) • Chicago . Cleveland . Denver * D etroit Houston . K ansas C ity . M ilw aukee • M inneapolis • Newark (N . J .) • New York • P h ila d e lp h ia . P itts b u rg h
Providence (R . I .) • S t. Louis • U tica <N. Y .)
Pacifie Coast Salem O ffices.* San Francisco • Los Angeles • Pacific N orthw ett Salet O ffice*: W enatchee (W ash.) . Y akim a (W ash.) In Canada: T he Nichols Chem ical Company, L im ite d . M ontreal • Toronto • Vancouver
Vol. 13, No. 2
M atter o f the Strictest Confidence
When new processes involve the use of new chem icals, or chem icals with special characteristics, the problem often arises as to where these prod
ucts may be obtained— especially if indica
tions are that such chem icals will later be required in fairly substantial quantities.
From sm all laboratory lots through pilot plant requirements to quantity production, the furnishing o f such chem icals is a fam iliar path to Baker & Adamson. Our facilities and
experience can save you time and money.
You may present your problems to us knowing that their details w ill be held in the strictest confidence. In addition, we can usually offer helpful assistance on specifica
tions. From then on, your problem is ours.
You are relieved of details. Your product is produced in our plant and delivered to your door, known only b y number, if you so desire.
Arrange a conference on your problem to
day. Write or call nearest office listed below.
February 15, 1941 A N A L Y T I C A L E D I T I O N 9
H O S K I N S P R O D U C T S
E LE C T R IC H I AT T R E A T IN G FU R N A C E S • • H E A T IN G ELEM EN T A L L O Y S • • T H E R M O C O U P LE AND LEAD WIRE • • PYROMETERS » • WELDING WIRE • • HEAT RESISTANT CASTINGS • • ENAMELING FIXTURES • • SPARK PLUG ELECTRODE WIRE • • SPECIAL ALLOYS OF NICKEL • • PROTECTION TUBES
□How th e use o f the h eaviest p o ssib le C h ro m el w ire . Fo r e x a m p le , the 1 1 0 - V w ire is . 0 7 2 ' d i a . , f or 1 1 0 and 2 2 0 it w o u ld be . 0 4 5 ' .
INSULATION
Hoskins electric laboratory furnaces deliver the goods, month in and out. Their Chromel Units are du rable— almost beyond belief.
W e don’t invite you to abuse these furnaces, but if you must force them through an emer
g en cy, y o u ‘ll see what a good factor of safety has been built into them. H oskins Furnaces a re dependable. W rite to your d ealer or us. . . . H oskins Manufacturing Co m pan y, Detroit, M ich .
# W hen the unit wears out, a ll you need to buy is the Chromel wire itself, which comes as a coil.
# Y o u install the Chromel wire m erely by wrapping it around the grooved muffle.
# This furnace can be had , equipped with a small inexpensive pyrometer an d couple.
# The sliding door saves heat. To remove a crucible you don't need to open the door a ll the w ay.
# The turns of the Chromel coil are “ con
densed" to compensate for heat losses at the door.
# These furnaces are a v a ila b le as muffle, carbon combustion an d small crucible types, good for 1 8 5 0 -2 0 0 0 ° F.
T h e in su la tio n Is 4 W th ick a l l a ro u n d . Th e fu rn ace is w e ll m a d e in a l l resp e cts. W e d o n ’t b u ild a “ c h e a p " fur
n a c e , b e c a u s e a c h e a p fur
n a c e c a n 't b e g o o d . H o sk in s Fu rn a ce s a re c h e a p e r in the lo n g run .
10 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 13, No. 2
A. H. T . CO. S P E C I F I C A T I O N
R U B B E R S T O P P E R S H R - 1 0 8
IN N EW D E S IG N S , M A D E O F A BLO O M LESS, B LA C K , H E A T -R E S IS T IN G C O M P O S IT IO N O F S U P E R IO R A G IN G Q U A L IT Y
V e r tic a l c ro s s -se c tio n of H R - 1 0 8 se m i-so lid s to p p e r ,
sh o w in g re c e ss e d to p .
V e r tic a l c ro s s -se c tio n of H R - 1 0 8 o n e -h o le s to p p e r , s h o w in g H o u g h fu s ifo rm
o p e n in g .
V e r tic a l c ro s s -se c tio n of H R - 1 0 8 tw o - h o le s to p p e r , s h o w in g H o u g h f u s ifo rm
o p e n in g s.
R U B B E R S T O P P E R S , H R -1 0 8 , A .H .T . Co. S p e cific a tio n . I n c o r p o r a t i n g f o r t h e f i r s t ti m e i m p r o v e m e n t s b o t h m c o m p o s i t i o n a n d i n d e s i g n w h ic h a d d g r e a t l y t o l e n g t h o f u s e f u l life , u t i l i t y , c o n v e n ie n c e a n d s a f e t y i n h a n d l i n g . T h e s t o c k is , i n o u r o p in i o n , s u p e r i o r t o t h a t u s e d i n a n y o t h e r s t o p p e r
? i? W nV£ S / i i P ° ss f s.s e s g r e a t e l a s t i c i t y , c o n t a i n s m o r e t h a n 7 0 % o f p u r e v i r g i n g u m , c o n t a i n s le s s t h a n 0 . 7 5 / 0 s u l p h u r a n d is f r e e f r o m s u r f a c e s u l p h u r ; n o r e c l a i m e d r u b b e r is u s e d . T h e s t o p p e r s h a v e b e e n f o u n d m a c t u a l u s e t o w i t h s t a n d r e p e a t e d s t e a m p r e s s u r e s t e r i l i z a t i o n a t 1 2 0 ° C a n d l a b o r a t o r y b o m b t e s t s i n d i c a t e a life a p p r o x i m a t e l y fiv e t i m e s t h a t o f t h e o r d i n a r y s t o p p e r .
S E M I - S O L I D T Y P E
semi7®°l'd stopper replaces th e usual solid plug type. T he top is recessed so th a t th e u pper half of th e stopper advantages^ sufficient ru b b er m th e walls to perm it handling in the usual m anner. T his new design offers th e following
in c re a se d depth of seal betw een stopper and neck of bottle, flask, etc., into which it is com pressed; th e recessed top perm its deeper insertion th a n th e conventional ty p e because th e rubber can flow tow ard th e hollow portion w ith
m inim um resistance. 1
E lim inates popping out or working loose of stoppers a fter continued compression in use.
tended periods ° f form m g a Perm anent shoulder w hich ordinarily occurs when stoppers are compressed for ex- a tubu.la.tF e because side walls can be pressed tow ard th e hollow portion to loosen stopper.
R educes tim e required for special boring as only half the stopper m ust be pen etrated
R ecessed top fo n n s a well for lubricants such as w ater, glycerine, etc., when using a cork borer.
R ecessed top reduces th e w eight and therefore reduces th e cost per stopper.
O N E - H O L E A N D T W O - H O L E T Y P E S
T he design of th e one and two-hole types is th e result of th e invention of A. T . H ough, consulting leather chem ist form erly of P an s, France, who suggested replacing the cylindrical bore of the usual stopper by a fusiform opening w ith in- - f t f ° f t approxim ately twice as large as the opening visible in either end. These fusiform openings are Provided w ith funnel tops and 2 m m sealing rims a t top and bottom which increase in w idth as th e diam eter of the inserted tube, etc., increases. T his new construction offers th e following advantages:
W ^ 6r , T fie tT ’ ,steim s’ e.tc -> can be in se rte d m uch m ore readily th a n into conventional stoppers, h u t are held firmly b y th e elastic sealing rim s a t top and bottom .
jia rtic u la rl^ b j^ «tiidents ^ ^ fusiform openings with g reater safety th an into the usual cylindrical openings, The funnel tops of th e fusiform openings facilitate entrance of tu b in g etc.
The fusiform openings perm it insertion of m uch larger tu b es th a n is possible in th e usual cylindrical openings. For example, glass tubes from 6 to 11 m m outside diam eter, w ith unfinished ends, and porcelain funnel stem s up to 20 m m diam eter can be inserted m properly lubricated stoppers from sizes No. 5 to 8, incl., w ith com parative
ease and w ithout special boring. F
T he fusiform openings reduce th e w eight and therefore reduce the cost per stopper.
H R-108 Stoppers are sold b y count an d n o t by w eight and, because of th e low specific g rav ity an d the new design include /0 “ ore stoppers per pound th a n m any brands now in wide use for laboratory work. T h ey are packed in for econom icSS’purehasem g m ultlples ot a dozen (aPProx- one P0™«* b Y w eight) of one size, for convenient shelf storage and
Copy of descriptive pam phlet, giving detailed inform ation as to sizes available, prices, etc., sen t upon request.
i i, F *ee. s a m p l e s o f H R - 1 0 8 R u b b e r S t o p p e r s a r e a v a il a b l e — w i t h s o m e l i m i t a t i o n s — f o r t r i a l i n o r g a n i z e d l a b o r a to r ie s . I n r e q u e s t i n g s a m e , p l e a s e s t a t e s i z e a n d s t y l e d e s ir e d .
ARTHUR H. T H O M A S COMPANY
R E T A IL — W H O L E S A L E — E X P O R T
L A B O R A T O R Y A P P A R A T U S A N D R E A G E N TS
W E S T WAS HI NGT ON S QUAR E, P H I L A D E L P H I A , U. S. A.
C a b le A d d r e s s , “ B a l a n c e ,” P h i l a d e l p h i a
INDUSTRIAL a n d ENGINEERING CHEMISTRY
A N A L Y T I C A L E D I T I O N
P U B L I S H E D B Y T H E A M E R I C A N C H E M I C A L S O C I E T Y • H A R R I S O N E . H O W E , E D I T O R
Organic Halogen Compounds in Mineral Oils
D e te c tio n , D eterm in a tio n , a n d Id e n tific a tio n
M . S . A G R U S S , G E O R G E W . A Y E R S , Jr., a n d H A N S S C H I N D L E R T h e P u r e O il C o m p a n y , C h i c a g o , 111
D
U R I N G th e p a s t fifteen years, a n d p a rtic u la rly during th e p a s t five years, a d d itio n of organic halogen comp o u n d s to v a rio u s ty p e s of m in eral oils h as becom e a prac
tic e in th e p e tro le u m in d u s try . T h ese m ix tu res include a w id e ran g e of p ro d u c ts, such as fireproof cleaning solvents, c u ttin g oils, b re a k -in oils, a n d special lu b ric a n ts. I n almost e v e ry case th e halogen co m p o u n d u sed in th e m ix tu re is a ch lo rin e com p o u n d . M e th o d s fo r th e d etec tio n , determ ina
tio n , a n d id en tificatio n of th e organic halogen com pound or c o m p o u n d s p re s e n t in m in eral oils are th e re fo re necessary in th e e x am in atio n of such p ro d u cts.
M e th o d s a re in clu d ed in th e p re s e n t p a p e r fo r (1) th e deter
m in a tio n of to ta l halogen (such as chlorine) in a n oil, (2) the d e te rm in a tio n of th e ty p e of halogen com pound present—
i. e., w h e th e r th e chlorine is o r is n o t a tta c h e d d ire c tly to an a ro m a tic ring— a n d (3) th e possible id en tificatio n of the h alo g en co m pound p resen t.
D e t e r m i n a t i o n o f T o t a l H a lo g e n
A n u m b e r of w ell-know n m e th o d s h a v e b een advanced fo r th e d e te rm in a tio n of halogen in organic com pounds or in m in e ra l oils, b u t th e se consum e too m u ch tim e to be used in o rd in a ry la b o ra to ry o p eratio n s. T h e follow ing m eth o d , in w h ich th e h y d ro g en chloride fo rm ed d u rin g com b u stio n of the m in e ra l oil in a P a r r oxygen b o m b is ab so rb ed b y sodium bi
c a rb o n a te so lu tio n (in th e bo m b ), w hich is in tu r n titra te d w ith s ta n d a rd silver n itr a te so lu tio n b y e ith e r th e M o h r or V o lh ard p ro ced u re, is ra p id a n d a c c u ra te a n d h a s given ex
cellen t re su lts o v er a p erio d of several years.
Pr o c e d u r e. A bout 20 ml. of distilled w ater, in which is dis
solved 0.500 gram of c. p. sodium bicarbonate, are placed in a P a rr oxygen bomb of 400-ml. capacity. From 0.6 to 0.8 gram of th e oil to be tested is placed in th e weighed oil cup and th e weight of th e charge is determ ined to th e nearest milligram. T he cup is th en placed in th e bomb, which is previously arranged so that th e iron firing wire (10 cm.) touches the oil sample when the cup is placed in position. T he bom b is tig h tly closed and oxygen a t 30 atm ospheres is adm itted, after which th e ignition is carried out in th e usual m anner in a container of cold w ater. A fter ignition the bom b is allowed to cool (10 m inutes) and th e pressure is released a t a uniform ra te such th a t the operation requires not less th an 1 m inute.
T he bom b is opened and th e inside is examined for traces of unburned oil and sooty deposit. If either is found, th e deter
m ination is discarded. If complete com bustion has taken place, th e interior of th e bomb, including th e oil cup, is rinsed with a fine je t of distilled w ater into a 400-ml. beaker. T he washings usually do n o t exceed 350 ml. To th e beaker is added 1 ml.
of 2.5 per cent potassium chrom ate indicator solution and the halogen content is determ ined by titra tio n w ith 0.05 N silver
n itra te solution. In order to obtain a sharp end point, it is essen
tial th a t th e solution be viewed through brig h t yellow glass d u r
ing th e titra tio n w ith silver n itra te solution. A blank d eter
m ination m u st be carried out, in w hich 0.500 gram of th e e. p.
sodium bicarbonate, dissolved in exactly th e same volum e of w ater used in the beaker during th e te st, is titra te d u n d er th e sam e conditions as when th e sam ple was used. T he halogen co n ten t is calculated in th e usual m anner a fter th e q u a n tity of silver n itra te solution used in th e blank is su b tracte d from th a t used for the sam ple.
I f th e particular halogen present—brom ine, chlorine, or iodine—
is unknow n, a second sam ple is burned in th e bom b an d th e contents are examined b y th e usual q u alitativ e procedure.
T y p ic a l re s u lts b y th e ab o v e p ro c e d u re are show n in T a b le I .
Ta b l e I. De t e r m i n a t i o n o f To t a l Ha l o o e n i n Lu b r i c a t i n g Oi l
H a lo g e n C o m p o u n d A d d e d H a lo g e n C a lc u la te d F o u n d
% %
n - H e p ty l b r o m id e 0 .0 4 5 0 .0 4 4
0 .4 5 0 0 .4 6 0
n - A m y l c h lo rid e 0 .3 3 3 0 .3 2 4
T r i p h e n y lm e th y l c h lo rid e 0 .0 1 4 0 014
0 .1 4 2 0 .1 4 0
E t h y l e n e d ic h lo r id e 0 .0 6 9 0 .0 6 7
0 .6 9 0 0 695
B e n z y l c h lo rid e 0 .0 2 8 0 0 29
0 .2 8 0 0 .2 9 4
o -D ic h lo ro b e n z e n e 0 47 9 0 4 7 0
0 .0 4 8 0 .0 5 0
D e t e r m i n a t i o n o f T y p e o f H a lo g e n C o m p o u n d P r e s e n t
P ro c e d u re s g iv en in th e lite r a tu re a n d w ell-know n q u a lita tiv e organic te x ts a re v e ry in d efin ite w ith re s p e c t to experi
m e n ta l d e ta ils fo r th e d e te rm in a tio n of th e ty p e of h alo g en co m p o u n d p re s e n t. P o ta s siu m a n d so dium h y d ro x id e solu
tio n s, b o th aq u eo u s a n d alcoholic, h a v e lo n g b een su g g ested as re a g e n ts fo r th is p u rp o se. I t h a s b een fo u n d t h a t 1 N alcoholic p o ta s siu m h y d ro x id e so lu tio n w hen boiled 5 m in u te s w ith th e sam p le does n o t re a c t w ith h alogen a tta c h e d to a n a ro m a tic rin g ex cep t in th e case of io d in e w here a p o sitiv e g ro u p such as a c arb o x y l o r a ld e h y d e g ro u p is in th e o rth o po sitio n . P ra c tic a lly all o th e r org an ic h alogen co m p o u n d s are a tta c k e d b y th e alcoholic p o ta s siu m h y d ro x id e so lu tio n .
Pr o c e d u r e. F rom 0.1 to 0.2 gram of th e halogen com pound or 8 cc. of m ineral oil containing a halogen compound is placed in a 15-cm. (6-inch) te s t tu b e w ith 8 cc. of 1 N alcoholic potas
sium hydroxide solution (prepared from special potassium hy
droxide containing n o t more th a n 0.002 per cent chlorine an d 95
70 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 13, No. 2
Ta b l e I I . Re a c t i v i t yo f Or g a n i c Ha l o g e n Co m p o u n d s ( W ith 1 N a lc o h o lic p o ta s s iu m h y d ro x id e a n d s a tu r a te d s ilv e r n it r a t e
s o lu tio n s) P o s itiv e R e a c tio n w ith 1 Ar A lco h o lic K O H
N e g a tiv e R e a c tio n w ith 1 N A lco h o lic K O H P o s itiv e r e a c tio n
w ith alco h o lic A gNO a Is o p ro p y l b ro m id e
» - B u ty l ch lo rid e I s o b u ty l b ro m id e n - B u ty l b ro m id e n -A m y l ch lo rid e n -A rn y l b ro m id e I s o a m y l b ro m id e I s o a m y l ch lo rid e n - H e p ty l b ro m id e T r ip h e n y l m e th y l c h lo rid e B e n z y l ch lo rid e B e n z y l b ro m id e lie x a c h lo r o e th a n e p -P h e n y lp h e n a c y l b r o
m id e C h lo ro a c e ta l D ic h lo ro p e n ta n e C h lo ro c y c lo h e x a n e p -N itr o b e n z y l b ro m id e B u ta d ie n e te tr a b r o m id e T ric h lo ro a c e tic ac id C a r b o n te tr a c h lo r id e Io d o fo rm
E th y le n e d ib ro m id e E th y lid e n e b ro m id e o -Io d o b en zo ic ac id S lig h tly p o s itiv e r e a c tio n
w ith alco h o lic AgNO » P ro p y le n e d ic h lo rid e C h lo re x
/3 -P h e n o x y -£ '-c h lo ro e th y l e th e r
M o n o c h lo ro a c e tic ac id M e th y le n e c h lo rid e C h lo ro fo rm E th y le n e d ic h lo rid e 1 ,1 ,2 -T rib ro m o e th a n e
N e g a tiv e r e a c tio n w ith alco h o lic A gN O a A c e ty le n e te tr a c h lo r id e T r ic h lo ro e th y le n e T e tr a c h lo r o e th a n c P e n ta c h lo r o e th a n e T e tr a c h lo r o e th y le n e
C h lo ro b e n z e n c T ric h lo ro b e n z e n e o -D ich lo ro b en zen e o t-C h lo ro n a p h th a le n e p -C h lo ro d iip h en y l p -B ro m o a n ilin e C h lo ro h y d ro q u in o n e B ro m o b e n zen c a - B r o m o n a p h th a le n e T e tr a c h lo r o n a p h th a le n e p -D ib ro m o b c n z e n e p -D ic h lo ro b e n z e n e Io d o b e n z e n e
per cent ethyl alcohol). T he test tube is placed in a steam b ath for exactly 5 m inutes; then 5 cc. of distilled water are added and the contents are filtered through W hatm an No. 42 filter paper.
T he filtrate is acidified w ith dilute nitric acid; if turbid it is filtered through sufficient filter paper to give a clear solution.
T o this solution is added 0.5 cc. of 0.05 N silver n itrate solution and it is examined for turbidity due to silver halide. Blank tests on the reagents are carried out in the same m anner. Any excess of turbidity over th a t given by a blank test on the reagents used indicates the presence of organic halogen not attached to an arom atic ring (except w ith a few iodine compounds as stated above).
T h e resu lts o b tain ed w ith a n u m b er of organic halogen com pounds are show n in T ab le I I . F o r purposes of com
parison, resu lts o b tain ed b y h eatin g th e halogen com pound w ith a sa tu ra te d solution of silver n itra te in absolute alcohol a re also included.
T h e sen sitiv ity of th e te s t for th e d eterm in atio n of organic halogen com pounds in m ineral oil is show n in T ab le I I I .
I n case th e tw o ty p es of organic halogen com pounds are p resen t in th e sam e sam ple of m ineral oil, th e halogen n o t a t tach ed to a n aro m atic ring m ay u su ally be rem oved from th e oil b y continued refluxing w ith 1 N alcoholic potassium hy
droxide u n til th e halogen c o n te n t of th e m ineral oil decreases to a c o n sta n t value, th is la tte r value in d icatin g th e a m o u n t of halogen a tta c h e d d irectly to a n aro m atic ring.
I d e n t i f ic a t i o n o f H a lo g e n C o m p o u n d P r e s e n t M in eral oils co ntaining halogen com pounds m a y be dis
tilled in vacuo, th e halogen com pounds u su ally being con
c e n tra te d in one or m ore of th e fractions o b tain ed . U pon exam ining th e results o b tain ed b y th e m ethods m entioned above an d th e physical c o n stan ts of th e fractions, th e halo
gen com pound p resen t u su ally is readily identified an d a d eriv ativ e m a y be p rep ared if desired. T h is exam ination of th e fractions is tim e-consum ing a n d m ay be replaced in m an y instances b y a sim ple procedure by w hich th e halogen com pound m ay be ex tra c te d from th e m ineral oil as a th iu ro n iu m s a lt an d identified b y m eans of th e corresponding th iu ro n iu m p icrate.
Pr o c e d u r e. One hundred gram s of mineral oil and 50 cc. of c. p. benzene are refluxed for 2 hours w ith 10 cc. of 95 per cent ethyl alcohol containing 1 gram of thiourea. The alcohol layer is separated and the oil extracted w ith 25 cc. of hot 95 per cent alcohol, after which the two alcohol solutions are combined and evaporated to dryness on a steam bath. T he resulting thiuro
nium salt is washed w ith cold hexane to remove traces of oil, then dissolved in 10 cc. of 95 per cent alcohol, and 1 gram of picric acid is added. T he m ixture is heated on th e steam b ath until complete solution is attained, then allowed to cool slowly. T he thiuronium picrate is filtered oil, washed w ith 5 cc. of cold 95 per cent alcohol, then repeatedly recrystallized from 95 per cent alcohol until the m elting jx>int becomes constant. Usually two recrystallizations are sufficient.
T ab le IV shows th e m elting p o in ts of th e th iu ro n iu m picrates ob tain ed b y th is procedure from several portio n s of lu b ricatin g oil to w hich h a d been a d d ed th e com pounds listed.
Ta b l e IV . Me l t i n g Po i n t s o f Th i u r o n i u m Pi c r a t e s De r i v e d f r o m Ha l o g e n Co m p o u n d s i n Lu b r i c a t i n g Oi l
H alo g e n C o m p o u n d A d d ed to L u b r i
c a tin g O il (1 % in E a c h C ase)
F o u n d (p ic ra te d e riv e d fro m
h alo g e n co m L i te r a tu r e p o u n d in oil) v a lu e ( / )
° C . ° C.
151 154
138 142
170
259 260
188 188
n -A m y l ch lo rid e n - H e p ty l b ro m id e T r ip n e n y lm e th y l ch lo rid e E th y le n e d ic h lo rid e B e n z y l ch lo rid e
Since no value for th e m elting p o in t of s-trip h en y lm eth y l th iu ro n iu m p ic ra te w as av ailab le in th e lite ra tu re , th is com
p ound w as prep ared b y refluxing trip h en y lm eth y lch lo rid e w ith th io u rea in alcoholic solution, followed b y ad d itio n of picric acid a n d recry stallizatio n from alcohol. T h e m elting p o in t w as 172° C. an d analysis of th e com pound in d icated 5.4 p er cen t of su lfu r (theoretical, 5.85 per cent).
L it e r a t u r e C ite d
(1) Levy, W. J., and Campbell, Neil, J . Chem. Soc., 1939, 1442.
Pr e s e n t e d b e fo re th e D iv isio n o f P e tr o le u m C h e m is tr y a t th e 1 0 0 th M e e tin g of th e A m e ric a n C h e m ic a l S o c ie ty , D e tr o it, M ich .
N o te on D eterm in a tio n o f S ilica in C alcin ed A lu m in a
Ta b l e I I I . Se n s i t i v i t y o f Te s t f o r Ha l o g e n i n Lu b r i c a t i n g Oi l
D e te c te d b y T e s t
%
( W h e re h a lo g e n is n o t a t ta c h e d t o a n a r o m a tic rin g )
C o m p o u n d M in im u m H a lo g e n C o m p o u n d M in im u m H a lo g e n P r e s e n t D e te c te d by T e s t P r e s e n t
%
H e x a c h lo ro e th a n e T ric h lo ro e th y le n e P e n ta c h lo r o e th a n e E th y le n e d ic h lo rid e M o n o c h lo ro a c e tic a c id T ric h lo ro a c e tic a c id C h lo re x
n -A m y l ch lo rid e n - H e p ty l b ro m id e B e n z y l ch lo rid e C h lo ro fo rm C a r b o n te tr a c h lo r id e T r ip h e n y lm e th y l
cn lo rid e
0.002 0.002
0.001
0 .0 0 5 0 .0 0 5
0.001
0 .0 0 5 0 .0 0 4 0 .0 0 4 0 .0 0 4 0 .0 0 2 0 .0 0 3 0 .0 0 3
J . E . E D W A R D S
154, I l i l l c r o f t C r e s c e n t, O x h e y , W a t f o r d , H e r t s , E n g la n d
T
H E d eterm in atio n of traces of silica in calcined alu m in a required for th e m a n u fa c tu re of alu m in u m p resen ts a n u m b er of difficulties. T h e a u th o r has found t h a t silica m ay be determ ined in calcined alu m in a colorim etrically as silico- m o ly b d ate in acid solution a n d th a t th is m eth o d is quicker a n d m ore accu rate th a n th e g rav im etric m eth o d . I t m a y also be a d a p te d to m a n y estim atio n s of sm all am o u n ts of silica o r silicon.A Rapid Method for Determining Ferric and Ferrous Iron
JO H N O. PE R C IV A L, M e r rin ia c D ivision o f M o n s a n to C h c m ic a l C o., E v e re tt, .Mass.
U s in g p r e c ip it a te d co p p e r a s a r e d u c in g a g e n t , d e t e r m in a t io n s o f fe r r o u s a n d fc r r ic ir o n a re c a r r ie d o u t in le s s t h a n 10 m in u t e s , w it h a m i n i m u m o f e q u ip m e n t a n d s k ill, w it h c o m m o n s t a b le r e a g e n t s , in t h e p r e s e n c e o f la r g e a m o u n t s o f c u p r ic , fe r r o u s, m a n g a n o u s , z in c , n ic k e l, a n d c h r o m ic io n s , a n d w it h a p r e c is io n a n d a c c u r a c y o f a r o u n d 3 p a r t s p e r t h o u s a n d .
W
IT H m an y m ills tu rn in g to th e use of ferric sulfate for pickling b rass an d o th er copper alloys, th e need for a sim ple rap id m eth o d for th e determ in atio n of ferric ion in th e b a th s h as arisen. (M etals are pickled a fte r high-tem pera- tu re annealing to rem ove th e oxide film and to produce a b rig h t uniform appearance.)S ta n d a rd m eth o d s are u n satisfacto ry for th is purpose be
cause m ills d em and a m ethod so simple an d rapid th a t it can be carried o u t beside th e b a th b y regular w orkm en w ith o u t special tra in in g an d w ith o u t tak in g m uch tim e from th eir o th er duties. T h u s, all m ethods are elim inated w hich ta k e m ore th a n 10 m inutes, w hich require lab o rato ry skill, special a p p a ra tu s, an d u n u su al o r u nstable reagents, and w hich are expensive or in acc u rate in th e presence of large am o u n ts of cupric ion.
T h e m eth o d developed to m eet th ese requirem ents com
prises reduction b y finely divided copper, rem oval of th e ex
cess, a n d titr a tio n w ith sta n d a rd perm anganate.
M etallic copper has been used before for reducing ferric salts [1, 3 -5 , 7 -9 ), b u t in all cases copper w ith a relatively sm all surface are a per u n it of w eight, such as gauze, turnings, o r foil, has been used. T h is m akes th e procedures several tim es longer th a n th e present one and necessitates reduction in a boiling solution, w hich is an undesirable com plication in itself. F o r exam ple, H endel (5), who m ade a s tu d y of the tim e required to reduce various am o u n ts of iron, found 30 m in u te s’ boiling w ith 32 sq. cm. of copper gauze was required to reduce 125 m g. of iron. T h is q u a n tity , an d m ore, is re
duced in 2 m in u tes a t room tem p eratu re b y th e m ethod de
scribed.
N o one has previously poin ted o u t th a t th is m ethod is capable of d e term in in g th e ferric-ferrous ion ratio in th e pres
ence of large am o u n ts of cupric ion.
M a t e r ia ls
A glass-stoppered 250-cc. flask is preferable. Filtration fa
cilities are desirable b u t not essential.
Potassium perm anganate, 0.1 AT. Commercial anhydrous fer
ric sulfate (Ferrisul).
Copper m etal precipitated powder (a reagent electrolytic prod
u ct was purchased, 98 per cent, of which passed through a 325- mesh certified T yler sieve and 84 per cent of which is in the range 10 to 35 microns as determined by a W agner turbidim eter).
O ther reagents used in tests were of ordinary laboratory c . p.
grade.
M e t h o d
Add 50 cc. of water, 15 cc. of 20 per cent sulfuric acid, and a 4-cc. sample of filtered pickle b ath to the 250-cc. flask. T itrate w ith 0.1 Ar potassium perm anganate, add a slight excess of cop
per m etal precipitated powder (0.1 to 0.2 gram), shake violently
2 minutes, filter, and titra te again. One half the n et tite r gives per cent of ferric sulfate present. For convenience in titration the size of sample m ay be adjusted to give a tite r of 15 to 25 cc.
There m ust be an excess of copper present a t the end of the shaking, b u t an extremely large excess is not recommended in accurate work. F or cases where an error of 1 per cent is not serious, the filtration m ay be eliminated by shaking 30 seconds w ith 2 cc. of mercury and titratin g rapidly.
Ca l c u l a t i o n s.
1 cc. of 0.1 N KMnO, = 0.019993 grain of Ke2(SO(),
= 0.02 gram of Fea(SOi)s with error of only 0.035%
= 0.01519 gram of FeSOi
= 0.0152 gram of FeSO( with error of only 0.066%
% salt = grams of salt in 100 cc. of solution
Cc. of K M n 0 4 for 4 cc. of sample X 25 = cc. of KM nOi for 100 cc. of solution
N et cc. of 0.1 iV KM nOi X 25 X 0.02 = cc. of 0.1 N KMnO< X 0.5 = % of Fe2(SO,)3
(Cc. of 0.1 N K M nO (, 1st titer, - Blank) X 25 X 0.0152 = cc. of 0.1 N K M nO, X 0.38 = % of FeSO*
T h e th ree different F errisu l solutions used in testin g th e m ethod arc designated as I, I I , an d I I I . E la b o ra te precau tions or u nusual care are n o t required an d w ere n o t ta k e n in th is w ork except w here necessary in th e tw o sta n d a rd procedures used. D u p licate analyses w ere m ad e in all cases. T h e g r e a t
e st d ev iatio n of th e d u p licate analyses from th e ir average w as
± 0 .5 p er cent. T h e average d ev iatio n w as 0.3 per cent.
(T hese are percentages of a c tu a l value fo u n d ; in term s of per cen t ferric su lfate th ey are, for solutions I an d I I , 0.03 and 0.04 per cent, respectively.) Since th is precision is en
tirely satisfacto ry for th e purp o se a t hand, no a tte m p t w as m ade to d eterm in e th e lim its of precision a tta in a b le b y th is m eth o d . All p er c e n t co n cen tratio n s given are eq u iv alen t to g ram s of sa lt per 100 cc. of solution a t room tem p eratu re.
Ta b l e I. Co m p a r i s o n w i t h St a n d a r d Me t h o d s Fci(SO«)a F o u n d S o lu tio n I S o lu tio n I I
SO* m e th o d C u m e th o d SnCLt m e th o d
%
8 . 7 3
8 .7 2 1 2 .7 4
1 2 .7 1
Co m p a r i s o n w i t h St a n d a r d M e t h o d s ( Ta b l e I ) . T h e su lfu r dioxide reduction w as carried o u t according to a sta n d ardized procedure used here for p la n t co n tro l w ork.
Add the sample containing about 0.75 gram of ferric sulfate to 200 cc. of distilled w ater in a 500-ce. flask; raise the pH to point of precipitation and pass in a rapid stream of sulfur dioxide for 15 seconds. Bring to boil over 5-minute period (m ust be color
less) and add 10 cc. of 1 to 1 sulfuric acid. Boil rapidly until there is no odor of sulfur dioxide, or a t least 10 minutes. Cool and titra te w ith 0.1 N potassium perm anganate. M ake blank correction. About 30 m inutes are required.
T h e stan n o u s chloride red u ctio n a n d titr a tio n using th e Z im m erm an -R ein h ard t p rev en tiv e solution followed th e directions of S w ift (10). T h e ag reem en t of th e p resen t m ethod w ith in a b o u t 2 p a rts p e r th o u san d w ith th ese sta n d a rd m eth o d s is th u s less th a n experim ental error, an d shows th a t th e new m ethod is accu rate.
Ef f e c to f Ot h e r Io n s. T ab le I I shows th a t large am o u n ts of ferrous, cupric, m anganous, zinc, nickel, a n d chrom ic ions.
71
72 I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y Vol. 13, No. 2
Ta b l e I I . Ef f e c t o f Ot h e rI o n s ( F e rris u l S o lu tio n I I I )
A d d ed S a lt---. F ej(S O *h F o u n d
% %
8 .8 3
F eS O « .7 H iO 25 S.SG
C uSO «. 511tO 25 8 .8 1
M n S O * .2 H sO 62 S .7 S
Z n S 0 * .7 H 20 100 8 .8 7
N iS O ł.G lh O 4 2 .5 8 .8 7
Crj(SO <)i N a C l
3
25 8 .8 1
1 3 .1
do n o t affect th e m eth o d ou tsid e of experim ental error. Chlo
ride, a s w ould be expected, caused interference.
D is c u s s io n
A side from the sim plicity of a copper reduction m ethod, it h a s th e a ll-im p o rtan t a d v a n ta g e here of being applicable d i
rectly to b rass pickling b a th s containing large am o u n ts of cupric ions, w hich w ould n o t be th e case w ith a zinc or s ta n nous chloride reduction. T h e fa c t t h a t chloride is n o t re
quired as in a m ercu ry (2, 6) or silver (11) reduction m akes it possible to use a sim ple p erm an g an ate titra tio n . T h e a b sence of special a p p a ra tu s, such as a red u cto r tu b e or colori
m etric stan d ard s, m akes th e m ethod p a rtic u la rly suited to m illw ork w here such eq u ip m en t could be subjected to careless han d lin g an d breakage. T h e sim ple eq u ip m en t used in th is m eth o d is easily replaced w ith o u t th e a tte n tio n of a trained chem ist.
T he m eth o d requires no special skill an d th e accu racy and precision of th e resu lts show t h a t interference b y cuprous com pounds an d air oxidation is negligible. T h e use of pre
c ip itated copper pow der so accelerates th e red u ctio n t h a t th e m ethod becom es one of th e fa s te st an d sim plest of an aly tical m ethods, w hich should recom m end its use in o th e r applica
tions. T h e precision of th e resu lts is co n sisten t w ith th e technique used a n d no resu lts were o btained w hich w ould indicate t h a t th e m eth o d could n o t be m ade even m ore pre
cise th a n 3 p a rts per th o u san d , if desired, b y in tro d u cin g re
finem ents.
A c k n o w le d g m e n t
T he a u th o r wishes to acknow ledge th e assistance of D ennis J . K elley, w ho perform ed m o st of th e analyses.
L it e r a t u r e C ite d (1) Birch, Chem. News, 99, 273 (1909).
(2) Campbell and Hook, Soc. Chem. In d . Victoria Proc., 31, 544 (1931).
(3) Carnegie, J . Chem. Soc., 53, 471 (1888).
(4) Fontes and Thivolle, Bull. soc. chim., 33, 844 (1923).
(5) Hendel, In d. En g. Ch e m., 16, 951 (1924).
(6) M cCay and Anderson, J . A m . Chem. Soc., 43, 2372 (1921).
(7) Pickles, Chem. News, 124, 93 (1922).
(8) Scagliarini and Pratesi, A nn. chim. ajyplicata, 19, 85 (1929).
(9) Storch, Ber. Osterr. Ges. Forder. chem. Ind., 15, 9 (1893).
(10) Swift, E. H., “System of Chemical Analysis” , p. 303, New York, Prentice-IIall, 1939.
(11) W alden, H am m ett, and Edmonds, J . A m . Chem. Soc., 56, 350 (1934).
Volumetric Determination of Iron and
Aluminum in Cement with 8-Hydroxyquinoline
L E O K A M P F , D iv is io n o f A n a ly z in g u n d T e s t i n g , P r e s i d e n t o f t h e B o r o u g h o f Q u e e n s , L o n g I s l a n d C ity , N . Y.
I
N T H E usual procedure (3 -1 0 ,1 1 ,1 4 ) f°>' th e d eterm in atio n of iron an d alum inum w ith 8-hydroxyquinoline, th e acid ity is generally se t w ith acetic acid an d am m onium a c e ta te a t a pH close to 7, a n d a n acetic acid solution of th e 8-hydroxyquinoline is added to p re c ip ita te th e m etals.
R esu lts o b tain ed b y th is procedure are erratic. W hile th e g rav im etric resu lts are satisfacto ry , th e volum etric resu lts are co n sisten tly low ; alth o u g h th e m etals are com pletely precipi
ta te d , th e y do n o t come dow n com pletely as th e oxine. T h is is due to th e fa c t t h a t th e p H for p recip itatio n as th e oxine is th e sam e as for p recip itatio n of th ese elem ents as th e basic acetates. M o y er an d R em ington (12) h av e shown th a t iron is p recip itated com pletely w ith oxine a t a p H of 3.45 to 4.00 and a lu m in u m a t a p H of 5.0. A t b o th these p o in ts th e basic ace
ta te p recip itates. W hen th e m etals a re ignited to th e oxides th e resu lts are satisfacto ry , b u t w hen th e oxine p recip itate is w eighed, th e resu lts are a little low because th e basic acetates are lig h ter th a n th e oxines. I n th e volum etric d eterm in atio n th e m e ta l w hich comes dow n as th e basic a c e ta te is n o t d eterm in ed . T h e a m o u n t of e rro r w hich th is procedure can cause w ill depend on th e d ilu tio n , th e tem p e ra tu re , an d the tim e of heating, a ll of w hich fav o r th e fo rm atio n of th e basic a c e ta te .
T o p recip itate b o th iron a n d alum inum , th e p H m u s t be above 5.0. T h e ad d itio n of ta r ta r ic acid p rev en ts th e form a
tion of th e basic a c e ta te a t th is p H , an d th e m e ta ls can th e n be p recip itated com pletely as th e oxine.
Since d iv a le n t iron reacts w ith only 2 in ste a d of 3 m oles of
th e oxine, it is necessary to boil th e solution w ith brom ine w ater before a d d in g th e oxine.
Tw o m eth o d s fo r th e titr a tio n of th e oxine p re c ip ita te are used. T h e first— to titr a te th e oxine d irectly w ith a b ro m ate solution before using neocarm ine, m e th y l red, or o th e r dy e as th e in d icato r— is n o t generally used because th e color of th e dye fades g rad u ally and th e end p o in t is n o t sh arp (7, 13).
T h e second m ethod— to a d d a n excess of th e b ro m ate a n d b a c k -titra te w ith potassium iodide an d thiosulfate— can n o t be used in th e titr a tio n of th e iro n oxine because th e po tassiu m iodide also reacts w ith th e ferric ion.
T h e poor en d p o in t w ith th e first m eth o d w as therefore stu d ied . I t w as found th a t th e color produced in th is t itr a tio n w as n o t reversible. A v ery sm all a m o u n t of th e bro
m ate solution is able to decolorize a large a m o u n t of th e indi
cato r. T h u s, d u rin g th e titra tio n , th e in d icato r is being used up b y th e b ro m ate. T o elim inate th is i t is only necessary to ad d m ore in d icato r w hen th e so lu tio n s ta r ts to becom e de
colorized. A n o th er reason for th e poor en d p o in t is t h a t w hen m eth y l red, for exam ple, is used in a w eak acid solution, th e color change is from red to orange to green to yellow. T h e final tra n sitio n from green to yellow is v ery in d istin c t an d i t is easy to o v erru n th e end p o in t b y as m uch as 1 cc. If, how
ever, th e acid co n cen tratio n is above 15 p er cent, th e green color is elim inated an d a sh arp tra n sitio n from orange to yellow w ill be observed, th e red changing to orange ju s t before th e en d p o in t is reached. A satisfacto ry end p o in t can th en be o b tain ed b y d irect titr a tio n w ith th e b ro m ate solution.
