Industrial and Engineering Chemistry : analytical edition, Vol. 18, No. 3

INDUSTRIAL ^{a n d} ENGINEERING CHEMISTRY

A N A L Y T IC A L E D IT IO N

V O L U M E 18, N U M B ER 3 ISSU ED M ARCH 29, 1946 C O N S E C U T IV E N U M B ER 6

Assistant to Ed ito r: N . A . P A R K I N S O N

M anuscript E d itin s: G . G L A D Y S ^ G O R D O N

R. P. C H A P M A N J . R. C H U R C H IL L B . L . C L A R K E

E D IT O R : W A L T E R J. M U R P H Y A sso ciate Ed ito r: LAWRENCE T . HALLETT

Assistant Editors

M anuscript R eview in g : STELLA ANDERSON Advisory Board

T. R. CUNNINGHAM G. E. F. LUNDELL M. G. MELLON

C ontributing Ed ito r: R. H . MULLER

M ake-up: CHARLOTTE C . SAYRE

R. H . M U L L E R B. L . O S E R H . H . W IL L A R D

Boiling Range of Chlorinated H y d ro ca rb o n s...

D w ig ht W illiam s 15 7

Am perom etric Titration of Mercaptans with Silver Nitrate I. M . Kolthoff and W . E. H a rris 161

Determination of Tungsten in Silicate Rocks . E. B. Sandell 16 3

Equations of Thixotropic Breakdown for Rotational Viscom eter . . . H e n ry G re e n and Ruth N . Weltmann 16 7

Measurement of Sm all-A ngle X -Ray Scattering . . . . M . H . J e llin e k , Ernest Solom on, and I. Fankuchen 1 7 2

Polarographie Determination of A c e t a ld e h y d e ...

P h ilip J . Elving and Emile Rutner 1 7 6

Determination of Beryllium in O re s . . . M ary H . Fletcher, C h arles E . W h ite , and M ilto n S. Sheftel 1 7 9

Determination of Inorganic Phosphorus in Plant Materials . . W . A . Pons, J r ., and Jo h n D. G u th rie 1 8 4

Quantitative Determination of Ergosterol, Cholesterol, and 7 -D e h y d ro ch o Ie ste ro l...Frances W . Lamb,

A le x a n d e r M u e lle r, and G eo rg e W . Beach 18 7

New M ethod for Determination of M a n g a n e s e ...

^ James J . Lingane and Robert Karplus 191

Fractional Separation of Hafnium and Zirconium by Means of Triethylphosphate . H . H . W illa rd and H a rry Freund 19 5

Determination of Tocopherol in Plant T i s s u e ...

M o n ro e E. W a ll and E d w a rd G . K e lle y 19 8 Method of Evaluating M etal C l e a n e r s ...

Samuel Sp ring , H o w a rd I. Forman, and Louise F. Peale 201 Fluorometric Attachment for Beckman Spectrophotometer

M a ry H . Fletcher, C harles E. W h ite , and M ilto n S. Sheftel 2 0 4

M IC R O C H E M IS T R Y

Spectrophotometric Determination of Traces of N ickel . . O . R. A le x a n d e r, Edith M . G o d a r, and N . J . Lin d e 2 0 6 Amperometric Microtitration of V e ry Dilute Chromate

S o lu t io n s ... I. M . Kolthoff and D. R. M a y 2 0 8 Rapid Estimation of Rubber in G uayu le Latex Disper­

sions R. T. W hittenb erg er and B. A . B rice 2 0 9 M odified A ll-D ithizo n e Method for Determination of

Traces of Copper . S. L . M o rriso n and H a rrie t L . Paige 211

N O T E S O N A N A L Y T I C A L P R O C E D U R E S

Simple Automatic Control for Vacuum Systems . . . . J . J . Sp adaro, H . L. E. V i x , and E. A . G astro ck 2 1 4 Absorption Spectrum of Antim ony Trichloride-Ergosterol

Reaction P ro d u ct... A le x a n d e r M u e lle r 2 1 4 Large-Size Laboratory Soxhlet E x t r a c t o r ...

Ralph Salkin and Irving A lla n Kaye 21 5

B O O K R E V IE W S 2 1 6

Instrumentation in A n alysis . . R. H . M iille r (A d v t. Se ct.) 2 9

I h e Am erican Chemical Society assumes no responsibility for the statements and opinions advanced b y contributors to its publications. V ie w s expressed in the editorials are those of the editors and d o not necessarily represent the official position of the Am erican Chem ical Society.

W e acknow ledge w ith thanks the action of J. T. Baker Chem ical C o . in releasing the front cover of this issue for editorial purposes.

C o p yrig h t 1 9 4 6 b y Am erican Chem ical So cie ty.

3 7 ,2 0 0 cop ies o f this issue p rinte d.

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J..«

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

e Analysis Chart.

14 5

.

s through the use

•y Chemicals.

T H E Merck line of Reagents and C. P. Chemi­

cals, as well as those chemicals suitable for industrial research, educational, and routine plant laboratory uses, is comprehensive. C .P . and Reagent mineral acids and Ammonia Water are of highest purity, and are indicated wherever those acids are used.

The use of Reagent grade chemicals in plant operations is constantly increasing. If, ip your ex­

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ities are well adapted to the production of such custom-made chemicals.

MERCK & CO ., In c ., RAHW AY, N. J.

Please send me th e following ch arts:

R evised Q ualitative A nalysis C h a rt Periodic C h a rt o f th e E lem ents S ensitivity C h art

N a m e ...

C o m p an y ...

P o sitio n ...

C ity ...S ta t e ...

I N D . E N G .- 3 - 4 G

8 ? ‘V

■

M arch, 1946 A N A L Y T I C A L E D I T I O N 5

C O N S O L I D A T E D E N G I N E E R I N G C O R P O R A T I O N

\ 6 2 0 N O R T H L A K E A V E N U E • P A S A D E N A 4 , C A L IF O R N IA

M a n u f a c t u r e r s o f M a s s S p e c t r o m e t e r s , V i b r a t i o n a n d S t r a i n A n a l y s i s a n d R e c o r d i n g e q u i p m e n t

Q UICKER ANSW ERS

Com p utation time 1 / 5 to 1 / 1 0 that required b y m echanical calculators.

E A S Y TO OPERATE

Short operation training period.

E A S Y TO IN STA LL AND MAINTAIN O p e ra te s from lighting circuit.

W rite fo r n e w d e sc rip tiv e b u lletin .

6 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

u p o n w k ic k o u r liv es k a v e k e e n k u ilt, o n ly a fe w k a v e k e e n left u n c k a n g 'e d k y tk e w a r. A m o n g ' tk e s e is tk e u n ifo rm d e p e n d a k le p u r ity of M a llin c k r o d t A n a ly tic a l R e a g e n ts . S e n d for tk e M a llin c k r o d t A n a ly tic a l R e a g e n t c a ta lo g tog’e tk e r w itk a n y sp ecific in fo r m a tio n d e s ire d o n M a l ­ lin c k ro d t c k e m ic a ls to fit y o u r s p e c ia liz e d o p e ra tio n s.

, -

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Always Specify Reagents In Manufacturer’s Original Packages

D e p e n d a b le

^*

P u rity

C H E M I C A L W O R K S

M allinckrodt Street, St. Louis 7 , Mo.

7 2 G o ld Street, N ew York 8, N . Y .

C h ica go • Philadelphia • Los A ngeles • M ontreal

O F T H E E ST A B L ISH E D STA N D A R D S . . .

M arch, 1946 A N A L Y T I C A L E D I T I O N

O F L A B O R A T O R Y F U R N A C E S

H e re a r e fu rn ace s, the like o f w hich la b o r a t o r y technicians h a v e n e v e r s e e n — v a s t ly im p ro v e d in both function a n d a p p e a r a n c e . E n g in e e re d a n d built b y the le a d e r s in d e v e lo p in g a n d m a n u ­ facturin g industrial h e a t-tre a tin g equipm ent, they a r e the last w o rd in efficient a n d p ractical la b o r a t o r y fu rn ace s.

The Lindb erg B o x Furnace d e s ig n e d fo r fa st a n d a c c u ra te m e ta llu rg ic a l tests a n d chem ical a n a ly s e s h e a ts up to 2 0 0 0 ° F. H a s built-in tra n s­

fo rm e r; " S t e p le s s " Input C o n tro lle r a n d Indicating P y ro m e te r a r e c o n ta in e d in a s e p a r a t e m etal case.

The Lin db erg P ot-C rucible Furnace d o e s salt o r le a d b a th im m ersion te m p e rin g, h a rd e n in g a n d a n n e a lin g , c y a n id in g a n d alum inum h e at- tre atin g . O n the o th e r h a n d , a s a crucible fu r­

nace, it is u se d fo r d e te rm in in g critical points o f steel, m elting b a s e m etals, th erm ocoup le c a li­

b ra tio n s a n d o th e r n e c e s s a ry la b o r a t o r y o p e r a ­ tions f o r h e a ts u p to 2 0 0 0 ° F.

The Lindberg Com bustion Tube Furnace is d e ­ s ig n e d fo r fa st c a r b o n a n d su lp h u r d e t e rm in a ­ tions using the volum etric m ethod o f a n a ly s is a n d fo r g ra v im e tric t y p e a n a ly s e s fo r c a r b o n d e ­ te rm inations o f all a llo y steels inclu d ing stain le ss a n d h e a t-re sistin g steels. H e a ts u p to 2 5 0 0 ° F.

The Lindberg H ot Plates a re fo r precise, c o n ­ trolled a ll-ro u n d la b o r a t o r y use fo r t e m p e r a ­ tures up to 9 5 0 ° F. Built-in input control p r o v id e s e x a c t te m p e ra tu re selection.

The se fu rn a c e s ca n b e se c u re d fro m y o u r la b o r a t o r y e q u ip m e n t d e a le r. S e e him t o d a y f o r full inform ation.

L I N D B E R G E N G I N E E R I N G C O M P A N Y

2 4 5 0 W EST H U B B A R D S T R EET • C H IC A G O 12, ILLIN O IS

W E L L K N O W N T H R O U G H O U T T H E W O R L D A S L E A D E R S I N D E V E L O P I N G A N D M A N U F A C T U R I N G

I N D U S T R I A L H E A T T R E A T I N G E Q U I P M E N T

B 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

DU PONT

Another Forw ard D evelopm ent in Insecticides

H EXA CH LO RO CY CLO H EX A N E is a new an d o u tsta n d in g insecticid e. In th e a n n u a l H u rte r M em orial L ec tu re, d elivered on M arch 8, 1945, by D r.

R. E . Slade, R esearch C o n tro lle r of Im p erial C hem ical In d u s trie s, he stated , " T h e re h as now com e to ligh t w h a t p rom ises to be one o f scien ce’s im p o rta n t c o n trib u tio n s to the w elfare o f m a n .” D r. S lade re ferred to H exach lo ro cy clo h ex an e w hich was developed as an in secticide by Im perial C hem ical In d u s trie s u n d e r th e follow ing ad d itio n al nam es: benzene hexa- chloride, 666, a n d G am m exane.

D u P o n t has confirm ed the B ritish re co rd s of efficiency o f this re m a rk ­ able in secticid e in its ow n lab o ra to ries, an d is privileged to a n n o u n c e it will have H e x ach lo ro cy clo h ex an e available th is season in m o d era te q u a n ­ tities fo r ex p e rim en tal use. In q u irie s from researcli in s titu tio n s and q u ali­

fied in v estig ato rs are in v ite d , an d on re q u e s t a copy o f D r. S lad e’s le c tu re will be m ailed as so o n as it is available fo r d is trib u tio n . G rasselli C hem icals D e p artm en t, E. I. du P o n t de N e m o u rs & C om pany. (In c.), W ilm ington 98, D elaw are.

R E 6 . U . S . P A T .Off-

B E T T E R T H I N G S F O R B E T T E R L I V I N G .. . T H R O U G H C H E M I S T R Y

IR O N

REFERENCE VANADIUM TUN G STEN

ALUMINUM

within 45 SECONDS after Your Sample is placed in the Quantometer

5 ' 6 n 7 8

( i n ‘‘J - -.v ;\i- 'p .- f.

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MOLYBDENUM COLUM BIUM 1

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CO PPER TITANIUM

Chemical Analysis at a GLANCE

M arch, 1946 A N A L Y T I C A L E D I T I O N

"it T h e Q u a n to m e te r c o n sists o f a sp e c tro m e te r an d a re c o r d in g c o n so le . T h e sp e c tro ­ m e te r m easu res p h o to -e le c tric a lly the sp ectral en erg y o f th e v ario u s m etallic elem en ts in an e le c tric a lly ex cited sam p le.

T h e Q u a n to m e te r w ill analyze eleven elem en ts in forty-five seco n d s. T h e actual ch em ical c o m p o s itio n , e le m e n t by elem en t, is sh o w n o n visual re c o rd e rs . T h u s, p re lim in a ry o r final analyses are im m ed iately available.

T h e costly " w a it-p e rio d s ” fo r an aly tical re tu rn s are e lim in ated an d "o ff-sp ecificatio n ” re je c tio n s a re m in im iz e d .

A Q u a n to m e te r-e q u ip p e d la b o ra to ry m ay be staffed w ith o n ly o n e o r tw o o p e ra to rs . T h e Q u a n to m e te r w ill save m an h o u rs an d m aterials. D etails o f th is re m a rk a b le d e ­ v e lo p m en t in th e field o f an aly tical in s tru m e n ts are n o w available. R e c o m m e n d a tio n s as to specific a p p lic a tio n s c a n be m ade.

Y o u r in q u iry is invited.

SILICO N M AN G AN ESE -,

CHROMIUM NICKEL

A P P L I E D R E S E A R C H L A B O R A T O R I E S 4 3 3 6 S A N FE R N A N D O R D „ G L E N D A L E 4 , C A L IF .

H A R R Y W . D I E T E R T C O . 9 3 3 0 R O S EL A W N A V E ., D ET R O IT 4 , M ICH .

P y R t X

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t £ S '

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... c » j « ! * = -

S q u a n t i t i e s 3 ^ 5 3 » C 4 » 5 - ^ N % C 5 H

• i - i n in h e n v l A m in e • Appr°x,rna,e'* ,,

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t

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A N A L Y T I C A L E D I T I O N

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-A-

T h e V i s i b l e G uarantee o f I n v i s i b l e Q u a lity

A N A L Y T I C A L E D I T I O N M arch, 1946

T o m e e t t h e varied a n d e x a c tin g r e q u ir e m e n ts o f R e s e a r c h , A n a ly s is a n d C o n tr o l in S c ie n c e a n d I n d u s tr y .

E X A X

T.M. REG. U.S.A.

Consult Leading Laboratory Supply Houses Through

>. out the United States and Canada for Kimble A Laboratory Classware to Meet YOUR Needs.

14 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

For Viscosity Measurements b y the Falling Ball Method

U navailable for the past several years, th e H oeppler Falling Ball Viscosimeter is now obtainable of domes­

tic m anufacture in the precision m odel as illustrated.

W ith th is instrum ent, absolute viscosities of gases and liquids can be determ ined w ith a greater degree of accuracy (0.1% to 0.5% ) and over a wider range (0.01 to 1,000,000 centipoises) th a n w ith o ther types of viscosimeters. Applications cover a range from gases to viscous liquids which will hard ly pour through a 16 m m . opening. M easurem ents are free from m an ip ulativ e variables. A ccurate results m ay be obtained even b y unskilled operator and m easurem ents repeated as often as desired w ith ou t replacing or transferring sam ple, m aking it particularly well suited for ro utine an d industrial use as well as for precise scientific research. A sam ple of 30 ml. only is required.

T h e absolute viscosity is determ ined b y m easuring th e tim e of fall of an accurately m ade ball of glass or steel through th e accurately calibrated distance betw een tw o m arks on th e glass tube. T h e balls an d glass tu b e are of optical pre­

cision, being accurate to w ithin 0.0005 mm . and th e center of g rav ity of each ball coincides w ith its geom etrical center.

T he replaceable glass tu b e has a coefficient of expansion identical w ith th a t of th e glass balls and is of non-corrosive heat-resistan t glass w ith heavy walls.

T h e glass tu b e is m ounted in a w ater jack e t a t an angle of 10° from th e vertical, th e m inim um inclination w hich insures a stra ig h t p a th of fall w ith o u t lateral oscillations and re- sultingly co n stan t a re a for fluid passage th ro u g h o u t th e period of descent. T h e tu b e is filled w ith th e sam ple an d closed w ith th e appropriately calibrated ball subm erged in

th e sam ple by m eans of a special capillary plug w hich per­

m its inversion w ith o u t introduction of a ir in to th e column, so t h a t as m any determ inations can be m ade as desired.

M easurem ents are th e n m ade b y accurately tim in g th e fall of th e ball th ro u g h th e distan ce betw een th e tw o m arks on th e glass tube, th e tim e in terv al being m ultiplied b y a factor, th u s obtaining absolute viscosity d irectly in centi­

poises.

T he in stru m en t is equipped w ith a special levelling stand, allowing free inversion of th e tu b e and ja c k e t u n it while m ain tain in g a 10° tu b e angle. Provision is m ade for th e m aintenance of a co n stan t tem p eratu re b y in let an d o u tlet w ater connections b u t for all o rdinary sam ples accurate determ inations m ay be m ade w ith o u t heating, a tem p eratu re higher th a n 20 °C. seldom being required.

17350—H O E P P L E R V IS C O S IM E T E R . Supplied w ith a set of six balls, consisting of two glass balls an d four balls of corrosion-resistant steel alloy in velvet-lined case; ball gage; therm om eter reading from 19° to 21°C. in 0.02° divisions; one ball tweezer; tw o gold-plated stoppers; one camel h air brush;

one cleaning piston; one glass rod; one cleaning brush; one chamois skin; an d one calibration certificate.

In polished wood instru m en t case w ith lo c k . ... $

^275.00

W I L L C O R P O R A T I O N

ROCHESTER 3 , N . Y . NEW YORK 12, N . Y .

BU FFALO A P P A R A T U S C O R P., BUFFALO 5 , N . Y .

A G A IN AVAILABLE!

THE HOEPPLER VISCOSIMETER

L A B O R A T O R Y A P P A R A T U S A N D C H E M I C A L S

C a n M e e t Y o u r

M o re than ^25,000 items are carried in stock by Harshaw Scientific Division of The Harshaw Chemical Co. • Y our requirements can be filled, w hether you need chem icals and ap p aratu s for a single experiment, or to furnish a complete laboratory. • Branch offices and stocks are maintained in con­

venient locations to help you obtain your requirements within a short time. • Send your order, with con­

fidence, to the Harshaw Scientific office nearest to you — Cleveland, Cincinnati, Detroit, or Philadelphia.

HARSHAW SCIENTIFIC

D I V I S I O N O F THE H A R S H A W C H E M IC A L C O . C L E V E L A ND 6, OHIO

M arch, 1946 A N A L Y T I C A L E D I T I O N I S

When you need LABORATORY CHEMICALS OR APPARATUS

H A R S H A W S C I E N T I F I C

16 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

4 S The MOISTURIMETER

^ (for u se w ith th e K a r l F is c h e r R e a g e n t)

li b y S cien tific G lass

D E V E L O P E D by Louis S attle r of B rooklyn College an d W illiam G eyer of Scientific : Jj ; G lass A pparatus C om pany, th is new ap p a ratu s has a num ber of exclusive fea­

tures which m ake it the m ost desirable instru m en t for m oisture analysis using th e K arl

Fischer R eagent. 1

T his reagent is widely used for th e q u a n tita tiv e determ ination of w ater in a variety of products. I t consists of a solution of iodine and sulfur dioxide in a m ixture of anhydrous m ethanol and pyridine. I t is extremely sensitive to atmospheric moisture,

and consequently it is imperative that titrations with it should be carried out in a ~

r

completely closed system, especially in those cases where m inute q u an tities

j» \\ 1» S of w ater are being determ ined. F urtherm ore, in view of th e fa ct th a t

/ the reaction mixture m ust be stirred during the titration, an ex tra difficulty is

J ⁽

thereby introduced into th e design of a suitable ap p aratu s.

)--- a

T h e S attler-G eyer M oisturim eter overcomes th e problem s of exclusion

r-Ci Sld l l

[ of atm ospheric m oisture and m echanical stirring in a closed system . I t I | / V consists of two 50-ml. autom atic burets which are so modified th a t th e | h

lower ends of th e barrels of th e Fresenius stopcocks are enlarged and

I } & /

formed into th e outer p arts of semiball joints. T h e titra tio n vessel is a / /

kv

/

w

flat-bottom extraction flask of 250-ml. capacity provided w ith a m outh, \ Vs ^ which is a m ale semiball joint, and a sidetube through which go th e m u- P - '- i i L g

tually insulated platinum electrodes sealed into a tu b e w ith a m ale jo in t ^ L % and connected to th e electro titra tio n ap paratus. T h e flask is covered V.____ _ w ith a bell-shaped dome, th e lower p a r t of which is a female semiball

joint. F rom th e top of the dome p roject tw o m ale semiball joints set

a t sufficiently differing heights to perm it free rotatio n of th e b u re t stop-

J-710

cocks. In addition, th e dome is provided w ith a checkvalve to perm it

( p a t e n t p e n d i n g )

venting of the ap p aratu s whenever liquid is being ad m itte d into th e flask from the burets. T h e male joints fit into th e burets which are provided

w ith stopcock plugs w ith tips extending into th e reaction flask. ^

S tirring is accom plished b y m eans of our M agnetic S tirrer, J-711.

--- F o r operating procedure, see Zerban,

I F . W ., and S attler, Louis, I & E C t a f

Anal. Ed., 18, 138-9 (1946), or

w rite for our B ulletin, 710. ^

J-713 S a ttle r W eight Pipet, consisting of a 15 ml. Erlenm eyer flask w ith T 1 9 /1 0 outside grind, provid-

^— — I ed w ith a cover i ' f : >" through w hich is sealed a medicine / \ dropper fitted w ith a / <§> \ sm all rubber b u lb ..

/ V \ S1-S0

/ \ J-711 M agnetic S tirre r $32.35 (Close up of T itra tio n Vessel)

\ __________ ) J-712 K arl F ischer R eag en t. C om plete4se t sufficient to prepare one q t. Fischer R eag en t _________________________________________ and one q t. w ater in M ethanol S ta n d a rd ... per se t $10.00

J-710 S attler-G e y er M o istu rim eter com­

plete b u t w ithout m agnetic s t i r r e r . . $65.00

BPPBRBTUS COMPANY.

M arch, 1946 A N A L Y T I C A L E D I T I O N 17

HIGH VACUUM with WATER

TODD SCIENTIFIC SPECIFICATIONS

A v a c u u m o f 0.008 m m . o f m e r c u r y (99.9989% e v a c u a tio n ) is r a p id ly p r o d u c e d w it h t h e c a li­

b r a te d T O D D H Y D R O -V A C P U M P ,* a s p e c ia lly d e s ig n e d a ll g la ss m e r c u r y d iff u s io n p u m p , w h e n u s e d i n s e r ie s w it h a n o r d in a r y w a te r a s p ir a to r p u m p c a p a b le o f p r o d u c in g 25 m m . o f v a c u u m o r b e t t e r . N o s u p p o r t in g m e c h a n ic a l p u m p is n e c e s s a r y .

T h e T O D D IIY D R O -V A C P U M P is designed to elim inate serious d isad ­ vantages inh eren t in th e o rd in ary piston ty p e vacuum pum p, such as is gen- nerally used by chem ical laboratories for th e evacuation o f distilling ap p aratu s.

Since th is highly efficient m ercury diffusion p u m p operates on th e diffusion principle, i t is n o t dam aged by th e presence of non-condensable vapors, w ater, or o th e r corrosive vapors w hich are frequently evolved during distillatio n proc­

esses. In ad d itio n , th is pum p is a m uch less expensive piece of a p p a ra tu s, is more po rtab le, an d occupies less tab le space th a n a m echanical pum p.

FEATURES:

V a c u u m o f 0.008 m m . o f H g re a d ily o b ta i n a b le .

N o t d a m a g e d b y n o il - c o n d e n s a b le v a p o rs , w a te r , o r o t h e r c o rro s iv e v a p o rs .

R a p id e v a c u a tio n o f a p p a r a t u s e s . E n ti r e ly a u t o m a ti c o p e r a t io n . C a lib r a te d fo r m a x i m u m v a c u u m .

H ig h ly e ff ic ie n t d u e to s p e c ia l t a p e r e d j e t c o n s t r u c t i o n .

C o m p a c t a n d s t u r d y s in g le p ie c e c o n s t r u c t i o n w i t h P y rc x b r a n d g la s s .

R e a d ily c le a n e d w i t h n i t r i c a c id . In e x p e n s iv e .

N e v e r w e a rs o u t .

1.

2

.

3.

4.

5.

6

.

7.

8. 9.

10

.

RECOMMENDED FOR

V acuum d istillatio n s V acuum fractio n atio n s V acuum ex tractio n s V acuum sublim ations V acuum pyrolyses

D rying app aratu ses of th e A bderhalden ty p e

M olecular still distillations D rying high boiling liquids in bulk A nd m any o th e r vacuum operations in

chem ical, physical a n d biological lab­

oratories.

TODD HYDRO-VAC PUMP

a s s h o w n a b o v e , c a li b r a t e d b u t w i t h o u t i n s u l a t i o n a n d m e r c u r y . C o m p le te o p e r a t i n g in s t r u c t i o n s

i n c lu d e d . H e ig h t , 13 in c h e s . . .$25 P R E S S U R E IN M I L L IM E T E R S

» T h e n a m e “ I I Y D R O - V A C ” i s r e g i s t e r e d i n t h e U n i t e d S l a t e s P a t e n t O f f i c e , a n d d e s i g n a t e s a p r o d u c t m a n u f a c t u r e d a n d d i s t r i b u t e d s o l e l y b y t h e

TODD S C IE N T IF IC CO M PA N Y

D esigners an d m anufacturers of special scientific lab o rato ry a p p a ra tu s.

S P R IN G F IE L D , PA.

1 c o m p l e t e s e t o f A U U U T i W T P a p e r s , c o m p r i s i n g 2 3 v i a l s (3 w i d e r a n g e s a n d 2 0 f r a c t i o n a l r a n g e s ) a n d a n A C C U T I N T M a s t e r C h a r t , $ 1 8 .2 0 .

A N A C H E M I A N E W Y O R K — 70 East 45th Street, N ew York 1 7, N . Y . MUrray H ill 6-0753

A N A C H E M IA 70 E.45 St., NEW YORK 17, N.Y.

S i m p l e

^—

N o I n s t r u m e n t R e q u i r e d Can B e E m p l o y e d A n y w h e r e C o l o r S c a l e o n E a c h V i a l

M a s t e r C o l o r Chart G r a p h i c C or r el at i on

ACCUTINT Test P a p e rs a re sim ple, ra p id a n d a c c u ra te m ean s of m aking h y d ro g e n ion d eterm inations. M erely p la c e a d ro p of th e solution b e in g ex ­ am in ed on a strip of th e test p a p e r, o b serv e th e color c h a n g e w h ich occurs, th e n m ake a com p arison w ith th e p rin te d color sta n d a rd on the vial. Each strip re a c ts to p ro d u c e a distinctive color re a c tio n at stated pH values w ithin its ra n g e o r in d ic a te s th a t an a d ja c e n t ra n g e m u st b e u se d for furth er determ ination.

ACCUTINT W id e R ange Test P ap ers p erm it q u ick d eterm in a tio n to establish th e p H v alu e w ithin 0.5 u n it in th e ra n g e 0 to 14 pH w hile F raction al R ange ACCUTINT Test P ap ers e n a b le closer app rox im atio ns to w ith in 0.1 a n d 0.3 of 1 pH unit. W h e re a pH v alu e ca n n o t b e closely estim ated, th e use of w ide ra n g e ' p a p e rs is re c o m m en d ed to localize th e pH v alu e suffi­

ciently for quick, effective u se of fractio n al ra n g e p ap e rs.

ACCUTINT P ap ers a re as sim ple to use as Litmus P a p e r b u t a re m any tim es m ore inform ative: the 23 different ra n g e s p ro v id e 144 se p a ra te color reactions. ACCUTINT P ap ers a re fu rn ish e d in p a d s of 20 strips ea ch , five p a d s to a vial.

DISTRIBUTORS

E . H . S A R G E N T & C O . — 1 55-16 5 E. Superior Street, Chicago 11, 111.

Michigan Div., 195 9 E. Jefferson, Detroit 7, M ich.

Serves M idd leW est, G ulf States and Mountain States o f West G E N E R A L L A B O R A T O R Y S U P P L Y C O . — Paterson 3, N . J. — SHerwood 2-1123

Serves the N ew Jersey Territory T H E E M IL G R E IN E R C O . — 161 Sixth A ven u e, N ew York, N . Y . PH IPPS A N D BIRD — Sixth and Byrd Streets, Richmond, Virginia

Serves Virginia, North Carolina, South Carolina

S T A N D A R D S C IEN TIFIC S U P P L Y C O R P . — 34 W . Fourth Street, N ew York, N . Y.

W IL L C O R P . — Rochester, N ew York

W ide R a n g e A C C U T IN T T e s t P a p e r s

(65c p e r V ial)

A co v e rs r a n g e 0 t h r o u g h 5 p H B c o v e rs r a n g e 1 t h r o u g h 12 p H C c o v e rs r a n g e 9 t h r o u g h 14 p H P a c k e d i n v ia l, 5 p a d s , ‘100 s t r i p s

(P le a s e sp e c ify r a n g e s d e s ire d ) F r a c t i o n a l R a n g e A C C U T IN T T e s t

P a p e rs (65c p e r V ial)

N o . F r a c t i o n a l R a n g «

1 0 ... 0 . 0 t h r o u g h 1 .2 2 0 ... 0 . 8 t h r o u g h 2 .4 3 0 ... 1 .3 t h r o u g h 3 .3 4 0 ... 1 .4 t h r o u g h 3 .0 5 0 ... 1 .7 t h r o u g h 3 .3 6 0 ... 2 .7 t h r o u g h 4 .7 7 0 ... 3 . 9 t h r o u g h 5 . 4 8 0 ... 5 . 0 t h r o u g h 6 . 6 9 0 ... 5 . 2 t h r o u g h 6 .9

1 0 0 5 . 3 t h r o u g h 7 .0

1 1 0 6 .1 t h r o u g h 7 .4

1 2 0 6 .9 t h r o u g h 8 ,4

1 3 0 7 . 2 t h r o u g h 8 .8

1 4 0 . . 7 . 3 t h r o u g h 8 .8

1 5 0 8 .4 t h r o u g h 9 .4

1 6 0 8 . 9 t h r o u g h 1 0 ,0

1 7 0 9 .1 t h r o u g h 1 0 .4

1 8 0 1 0 .1 t h r o u g h 1 2 .0

1 9 0 ... 1 0 .7 t h r o u g h 1 4 .0 2 0 0 . ...1 2 .4 t h r o u g h 1 4 .0

P a c k e d i n v i a l , 5 p a d s , 1 0 0 s t r i p s ( P l e a s e o r d e r b y R a n g e N u m b e r s ) M a s t e r A C C U T I N T C o l o r C h a r t , 21 . 1 0 % c o r r e l a t e s b y v a l u e a n d g r a p h i c a l l y a l l 1 4 4 p H v a l u e s , p e r c h a r t $ 3 .2 5 .

Hydrogen Ion Concentrations ^{c a n n o w}

BE M EA SU R ED W ITH IN 0.1 pH

W ITH ACCUTINT TEST P A P E R S

M arch, 1946 A N A L Y T I C A L E D I T I O N 19

If it has ^{to do} with DDT,

work it out with DU PONT!

M ANUFACTURERS

who have been thinking

of using DDT in their products are invited to come to Du Pont for technical service.

Experience gained as a major supplier of DDT to the armed forces may be of con­

siderable value to you.

That experience plus Du Pont’s continu­

ing laboratory and field studies make it possible to supply you with DDT Tech­

nical that always measures up to rigid requirements.

Because of the method by which it is manufactured, Du Pont DDT Technical is uniformly dependable. It works well in dry preparations and dissolves quickly, forming clear solutions.

To help you formulate DDT preparations that have a sound basis for commercial use, our complete facilities are available.

E. I. du Pont de Nemours & Co. (Inc.), Grasselli Chemicals Department, W il­

mington 98, Delaware.

B E T T E R T H I N G S F O R B E T T E R I J V I N G . . . T H R O U G H C H I M l S n Y

DDT Technical

20 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

A . H. T . C O . S P E C IF IC A T IO N

Q U A L I T A T I V E F I L T E R P A P E R

S u ita b le for a n a ly tical purposes other th a n those requiring th e use of an acid washed paper

5 1 6 0 . F i g . 2 . Show ing m e th o d of p a ck a g in g .

QUALITATIVE F IL T E R P A P E R , A. H . T. Co. Specification. A w hite p ap e r w ith em bhssed surface, m ade of carefully controlled 100% ra g sto ck of uniform texture.

S uitable for an aly tical purposes o th er th a n those requ irin g th e use of an acid w ashed paper, or one which com pletely re tain s fine p recip itates such as B ariu m S ulfate. W eight of ash is exceptionally low for unw ashed filter paper, i.e. ap pro x im ately 0.0006 gram s per 110 m m circle, as d eterm in ed b y im proved tests recen tly developed b y th e U. S. B ureau of S tan d ard s. See Research Paper R P1653, Journal of

Research of the N ational ( U. S .) Bureau of Standards, Vol. 34, N o. 5 (May, 1945), pp. 453 to 458.

W et burstin g stren g th , surface hardness an d filtering speed all have been considered carefully in th e m anufactu re to provide a p aper which is useful b o th in ed ucational an d in in d u strial laboratories.

5160. F ilter P ap er, Q ualitative, A. H . T. Co. Specification, as above described. Sizes up to an d including 380 m m d iam eter are packed in convenient cardboard carto n containing 100 sheets.

D iam eter, m m... 75___________ 90________ 100_________ 110_________125________ DIO________ 180 P e r pack of 10 0... .1 4 .1 8 .1 0 .2 0 .2 3 .2 0 .3 8 Code W o rd ... Foxau Foxcq Foxdo Foxem Foxgi Foxie Foxka D iam eter, m m... ' 200________ 250________ 330________ 3S0_________450_________500_________ 600 P e r pack of 1 0 0 ... .4 5 .7 5 1.17 1.68 2.11 2 .4 7 3.25 C o d e W o rd ... Foxnt Foxrl Foxih Foxyx Foybr Foycp Foyel

10% discount in lots of 100 packs j or more, 20% “ “ “ “ BOO “ ) one size or assorted

A R T H U R H. T H O M A S C O M P A N Y

R E T A I L — W H O L E S A L E — E X P O R T

LA B O R A TO R Y A PPA R A TU S AND R E A G E N T S

W E S T W A SH IN G TO N S Q U A R E, P H IL A D E L P H IA 5, PA ., U .S.A .

Cable Address “ B alance” Philadelphia

1 ____________

INDUSTRIAL ^{a n d} ENGINEERING CHEMISTRY

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 W A L T E R J. M U R P H Y , E D I T O R

Determination of the Boiling Range of Chlorinated H ydrocarbons

D W IG H T W I L L I A M S , Research Department, Westvaco Chlorine Products Corporation, South Charleston, W , V a .

A study of the factors that affect precision In the determination of distillation temperatures of chlorinated hydrocarbons showed that thermometer calibration errors cause some variation. The effect of variations in atmospheric conditions, such as the ambient temperature and drafts, is appreciable. The rate of distillation is important in some cases. The most important single factor is superheating of vapor. Because, over limited ranges, distillation temperatures are linear functions of the composition, it is possible to determine the composition of most binary mixtures and some ternary mixtures by this method.

S

E V E R A L y ears ago this corporation in itiated a stu d y of the d eterm in atio n of boiling ranges of relatively pure commercial solvents such as carbon tetrachloride and trichloroethylene. A stu d y of th e effect of num erous im purities on th e boiling range of pure solvents showed th a t, over lim ited ranges, distillation tem ­ p eratures were linear functions of th e composition. T hus, it is possible to determ ine the com position of m ost binary m ixtures and some te rn a ry m ixtures very sim ply from distillation tem ­ peratures.

A stu d y of th e precision of th e determ ination of distillation tem peratures showed th a t it was possible to estim ate relatively small concentrations of im purities from such d a ta . However, th e precision was far poorer th a n th e precision w ith which a m ercury-in-glass therm om eter m ay be rend. T h is led to a stu d y of th e factors which affect precision. T herm om eter calibration errors caused som e variation. A relatively sim ple piece of equip­

m ent was built for calibrating boiling range therm om eters. T he effect of variations in atm ospheric conditions, such as th e am bient tem p eratu re an d d rafts, was studied and w as shown to be ap­

preciable, a t least under extrem e conditions. T he ra te of dis­

tillation was show n to be im p o rta n t in th e case of some solvents, b u t not others.

T he m ost im p o rta n t single facto r contributing to lack of pre­

cision is probably superheating of the vapor. W hile no satis­

factory solution to th is problem lias been found, it is still under investigation an d it is planned to m ake this th e subject of a sub­

sequent paper. I t is believed th a t th e present paper will prove of some interest, since m ethods of th is ty p e are in general use for testing the p u rity of fluids.

A P P A R A T U S

T he shield, condenser, distilling fiask, and g rad u ate are those specified in A .S.T.M . D esignation D 86-38 for the determ ination of the boiling range of gasoline. T h e following ap p aratu s differs from thutspecified in th e A .S.T.M . m ethod:

. He a t e r. T h e h eate r sold under th e tra d e nam e Ful-K ontrol is used. T h e upper refractory is 1.9 cm. (0.75 inch) thick and has a 2.5-ein. (1-inch) hole in th e center. T he refractory is used plane side up.

Th e r m o m e t e r. Precision grade, length 40 cm. (16 inches), scale 23.8 cm. (9.5 inches), im mersion 10 cm. (4 inches) including bulb 1.9 cm. (0.75 inch) in length. Scale s ta rts 2.5 cm. (1 inch)

above line of im m ersion, expansion cham ber above bulb and above column, distance from b o tto m of bulb to top of lower expansion cham ber not over 3.8 cm. (1.5 inches), scale 40° C. in 0.1 ° C. divi­

sions. T herm om eters conform ing to these specifications and covering an y desired range m ay be purchased from T a y lo r In s tru ­ m en t Companies on special order. T he therm om eters are cali­

b rated a t th e boiling po in t of each fluid w ith which th e y are used, according to th e procedure described below.

Th e r m o m e t e r Re a d e r. C en tral Scientific C om pany C atalog 19,520 o r its equivalent.

PRO CED U RE

T h e h eate r is clam ped in to th e position in w hich it is to be used during th e distillation. A tig h t connection is m ade by m eans of a cork betw een th e vapor tu b e of th e flask an d th e condenser tu b e. T h e flask is ad ju sted so th a t its o u tlet extends into the condenser tu b e 2.5 to 5 cm. (1 to 2 inches). T h e therm om eter, provided w ith a cork, is tig h tly fitted into th e flask, so th a t it is in th e middle of th e neck of th e flask an d the to p of th e expansion cham ber is level w ith th e inside of th e b o tto m of th e o u tlet tu b e a t its junction w ith th e neck of th e flask. T h e im m ersion m ark should be close to th e b o tto m of the cork. W ate r a t approxi­

m ately room tem p eratu re is allowed to circulate th ro u g n the b a th .

T he h eate r is tu rn e d on long enough before sta rtin g th e dis­

tillation to m aintain a co n stan t ra te of distillation. T h e heater m ust be tu rn e d on a t th e volt age a t which it is to be used for a t least an hour, o r for a sh o rter tim e a t a higher voltage, before sta rtin g th e distillation. T h e voltage required to give a constant ra te of distillation of 5 to 6 ml. per m inute is determ ined em piri­

cally for each fluid.

A 100-ml. sam ple, w hich is approxim ately a t room tem p era­

ture, is m easured in a dry, 100-ml. g rad u ated cylinder and tra n s ­ ferred to the dry distillation flask. T h e therm om eter is placed in th e charged flask and th e flask is fitted to th e condenser. T he flask m u st be carefully fitted on to th e hole in th e refractory of th e heater. T he g rad u ated cylinder is placed w ith o u t drying u nder th e o u tle t of th e condenser.

T h e tem p eratu re is read and th e tim e recorded when th e first drop falls into th e g raduated receiver. T h e receiver is th en m oved so th a t th e tip of th e condenser touches the side of th e receiver. T h e tem p eratu re is read when the volum e in th e grad u ­ a te reaches 5 ml. an d 95 ml., and when th e distilling flask ju s t goes dry. All tem p eratu re readings are m ade by m eans of th e therm om eter reader and are recorded to th e nearest 0 .0 1 ° C. T he tim e is recorded a t th e dry point. T h e tim e betw een th e first drop and the d ry p o in t should be between 17 and 20 m inutes.

T h e barom eter and th e tem p eratu re alongside are read during th e course of th e distil!ati6n. T h e pressure is corrected for brass scale as follows:

Po = Pi - (f X P i X 0.000160)

where Po is th e b arom etric pressure in m illim eters of m ercury a t 0° C. an d P t is th e pressure a t te m p e ra tu re t. T he distillation tem p eratu res are corrected to 760-mm. pressure as follows:

T m = Poi,.. + d T /d P (760 - Po)

where Tiea and T oil. are th e corrected and observed distillation tem peratures, respectively.

T hese form ulas m ay be simplified in a given lab o rato ry in the 157