LABORATORY AND PLANT - The Journal of Industrial and Engineering Chemistry, Vol. 5, No. 12

D E T E R M IN A T IO N OF N IT R O G E N B Y T H E N IT R O M E T E R B y C . M . Jo y c e a n d Ha r r y La To u r e t t e

R eceived O cto b er 20, 1913

T h e n itro m e te r con sists of a gas ge n e ratin g bulb fitte d a t th e to p w ith a tw o -w a y co ck lead in g to a d isso lv in g cu p an d a gas e x it tu b e , and w hich has a t th e b o tto m a co n n ectio n fo r a ru b b er tu b e lead in g to a le v e lin g tu b e , th e w h ole b ein g filled w ith m ercu ry to a le v e l ju s t b elo w th e u p p er co ck ; a cylin d rical glass m easu rin g tu b e g ra d u a te d fro m o - io o cc. con n e cte d to a le v e lin g tu b e th ro u g h a T tu b e lead in g to an eq u ilib riu m tu b e . T h e la t te r is sh aped like an in v e rte d 100 cc. p ip e tte g ra d u a te d d o w n w ard below th e b u lb fro m 10 0 -130 cc. T h e w hole sy ste m is filled w ith m ercu ry so t h a t th e m easu rin g tu b e m a y be com p le te ly d isch arge d b y raisin g th e le v e lin g tu b e.

A D J U S T IN G T H E E Q U I L I B R I U M T U B E

T h e vo lu m e of 100 cc. of d ry air a t o ° C . and 760 m m . u n der th e te m p e ra tu re an d b aro m etric conditio ns

p re v a ilin g a t th e tim e is c a lc u la te d , th ree drops of 98 per ce n t su lfu ric a cid are d raw n in to th e tu b e and th e le v e l of th e m e rcu ry fixed in a cco rd an ce w ith th e calcu latio n . T h e co ck o f th e tu b e is th e n closed an d sealed w ith m elted p araffin . T h e v o lu m e in th is tu b e m a y be confirm ed a t a n y tim e b y o p en in g th e m easu ring tu b e and a d ju stin g

th e le v e lin g tu b e so th a t th e le v e l is th e sam e in th e th ree tu b es. T h e vo lu m e o f gas in th e eq u ilib riu m tu b e is th e n rea d an d co m p ared \Vith th e ca lc u la te d v o lu m e a t th e tim e, a correction in th e su b seq u en t gas readin gs in the m easuring tu b e being m ade a cco rd in g ly .

N IT R O G E N I N P O T A S S IU M N IT R A T E

A p p ro x im a te ly 0.4 gram p o tassiu m n itra te is p la ce d in a w eigh in g tu b e , d ried tw o hours a t 110 ° C ., d esiccate d 24 hours o v er su lfu ric a cid an d wre ig h e d e x a c tly b y difference in to th e cu p of th e gas ge n e ratin g b u lb . T h is is d issolved in 9 cc. 95 per cen t su lfu ric acid ad d ed th ro u g h a siphon th istle tu b e , e n te r in g th e to p o f th e d isso lvin g cup th ro u g h a tig h t-fittin g ru b b e r sto p p er. W h en th e sa lt is d issolved i t is d raw n in to th e gas g e n e ra tin g b u lb an d fo llo w ed b y tw o w ash ings 1.5 cc. each o f 95 per cen t acid. T h e bulb is th e n sh ak en w ith a m otio n n o rm a lto its lon g dim ension un til th e vo lu m e of gas d eterm in ed b y a rou gh pap er scale p a ste d on th e le v e lin g tu b e b ecom es co n stan t, th is op eratio n ta k in g fro m 3 to 5 m inutes.

T h e gas is passed in to th e m easuring tu b e and a fte r sta n d in g 5 m inu tes th e le v e lin g and m easuring tu b e s are so a d ju ste d th a t th e le v e l in th e eq u ilib riu m tu b e reads 100 cc. an d is th e sam e as th e le v e l in th e m easuring tu b e.

T h e read in g of th e la tte r is th e n ta k e n . A s th e te m p e ra tu re and b aro m etric con d itio n s, in so far as th e y a ffect th e m easured vo lu m e of th e gas, are a u to m a tic a lly com pen sa ted b y th e eq u ilib riu m tu b e , and as th e gas is w ash ed w ith su lfu ric acid an d is, th erefo re, d ry , th e p e rcen ta ge of n itro g en m a y be ca lc u la te d d ire ctly , c o rre ctin g o n ly for th e ca lib ra tio n of th e eq u ilib riu m an d m easuring tu b es.

S ev en teen d ete rm in atio n s m ade w h en th e room te m p e ra tu re ran ged from 20-28° g a v e 13 .7 1 per cen t n itrogen , th e th e o re tic a l b ein g 13.84 per cent.

E F F E C T O F R O O M T E M P E R A T U R E

I t w as n o ted th a t th e n itrogen d ete rm in atio n s of p y ro x y lin w hen th e room te m p e ratu re w'as o ver 30° C . ap p e ared a b n o rm ally high . D ete rm in atio n s of p o tassiu m n itra te w ere a cco rd in g ly m ad e a t te m p e ra tu res of 31—3 5 ° w h en th e th e o retical p e rcen tage w as ob tain ed . T h is w ould in d ica te th a t th e s o lu b ility of n itric oxide in 95 p e r cen t su lfu ric acid dim inishes p r a c tic a lly to zero under th ese con d itio n s. N itro g e n d eterm in atio n s of a well p u lp ed sam ple of n itro ce llu lose w ere m ade a t room te m p eratu re s ran gin g from 25° to 3 5 ° C . w ith th e resu lt th a t th e a p p a re n t p e r

cen tage in creased begin n in g a t 27° C ., b ein g 0.03 h igh er a t 28°, 0.07 a t 29°, 0.10 a t 29.5 0, 0.13 a t 30°, 0.20 a t 30.5 0, and 0.23 fro m 3 1 .0 ° to 3 5.o°.

T h e resu lts on n itrocellu lose h ad b een p re v io u sly cor

rected for s o lu b ility of n itric .o x id e in su lfu ric acid , th e correction b ein g based on th e differen ce b etw e en th e fo u n d and ca lc u la te d v a lu es for p o tassiu m n itra te . T his correc

tio n a m o u n ted to a p p ro x im a te ly 0.10 per cen t and w'ould acco u n t for a b o u t h a lf th e d ifference o b served w h en n itro - cellulose w as d eterm in ed a t th e te m p eratu re s before cited .

T h e g rea te r a p p a re n t increase in n itrogen in p y ro x y lin over p o tassiu m n itra te w ith rise of te m p e ra tu re can be a cco u n ted for o n ly b y th e p a rtia l b re ak in g up of th e cellulose in to carbo n m onoxide and carbo n dioxide.

i o i S T H E J O U R N A L O F 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 V ol. 5, No. 12 T h e fo rm atio n of carb o n d ioxid e has been p a r tia lly

in v e s tig a te d , th e c o n te n ts of th e m easuring tu b e from d e te rm in atio n s m ad e w h en th e te m p e ra tu re w as over 30° C ., h a v in g been passed th ro u g h an a b so rp tio n tu b e filled w ith b ariu m h y d ra te so lu tio n . T h is m eth od

offers som e d ifficulties, o w in g to th e sm all q u a n tity of carb o n d io xid e, th e presence of w hich has b een d ete r

m ined o n ly q u a lita tiv e ly th u s fa r. T h e e x a ct m easu re

m en t of th is gas and th e fo rm atio n of carb o n m onoxide w ill be in v e s tig a te d later.

D u p lic a te K je ld a h l d ete rm in atio n s o f th e sam p le of n itro cellu lo se d eterm in ed a t v a r y in g te m p eratu re s w ere 0.09 per cen t b elow th e figu re o b ta in e d w ith th e n itro m e te r b etw e en 20° and 28°. T h is d ifference is w ith in th e lim it of erro r o f th e tw o m ethods.

L I M I T A T I O N S O F N IT R O M E T E R

T h e n itro m e te r gives resu lts reliab le w ith in 0.02 per cen t on n itra te n itrogen , using 0.4 to 0.5 gram sam ple. I t is n o t a v a ila b le fo r th e d ete rm in atio n of n itro g en in cellu lo id or o th er su b sta n ces co n tain in g carb o n rin g com p o u n d s w h ich ap p e ar to p re v e n t th e co m p le te lib e ra tio n of n itric oxide in th e presence of su lfu ric acid an d m ercu ry.

S U M M A R Y

B esid es th e co rrectio n s for ca lib ra tio n a n d s ta n d a rd iza tio n of th e n itro m e te r in a cco rd an ce w ith te m p e r

a tu re and b aro m eter, th e g a s readin gs sh o u ld be co r

re cte d fo r so lu b ility of n itric oxid e, w h ich dim inish es w hen th e te m p e ra tu re goes a b o v e 28° C ., and th e fo rm a tio n o f o th er gases b y th e b re a k in g up of th e cellulose m olecule w h ich increases.

T h e fo llo w in g ta b le g iv e s th e a lg eb ra ic sum o f th e se tw o co rrectio n s fo r te m p e ra tu re s ran gin g fro m 20°

to 3 5 ° C .:

T e m p . Cc. T em p . Cc.

2 0 .0 - 2 7 .5 + 0 . 9 0 3 0 .0 — 0 .1 4

2 8 .0 + 0 . 7 4 3 0 .3 — 0 .7 0

2 9 .0 + 0 . 3 4 3 1 .0 - 3 5 .0 — 0 .9 4

2 9 .5 + 0 . 1 0

Ar l in g t o n Co., Ar l in g t o n, N . J .

L A B O R A T O R Y C O L U M N S T IL L B y H . K . Be n s o n

R eceived S e p te m b e r 22, 1913

In th e d e sc rip tio n 1 o f th e e q u ip m e n t of th e ch em ical en gin eerin g la b o r a to ry of th e U n iv e r s ity of W a sh in g to n , F ig. 9 o f P la te r sh o w s th e lo catio n of an alcoh o l still. D u rin g th e la s t y e a r, th ro u g h th e kin d n ess of a lo cal m a n u fa ctu re r, a w o rkin g m odel of a co n tin u o u s colu m n still h as been in stalle d , w h ich h as g iv e n e x cellen t resu lts in op eratio n .

T h e still, w h ich is m ade o f copp er, con sists e sse n tially of a p reh e ater, p rim a ry colu m n and r e c tify in g colu m n . T h e general p lan of c o n stru ctio n is sh o w n in th e sec

tio n a l d raw in g , F ig . x, and p h o to of th e in s ta lla tio n ,

--- Steam Supply

i m

F

. 1

F ig . 2. I t h as a to ta l cu b ic co n te n t of 9.24 gallons, w a te r m easure, and is c ap ab le of p ro d u cin g fro m 2 to 4 p ro o f gallo n s of alcoh o l in 8 hours.

T h e liq u id to be d istilled is fed b y g r a v it y in to th e p reh e ater fro m sm all sto ra g e ta n k s . T h e h e a t is fu rn ish e d in p a rt b y th e v a p o rs fro m th e p rim a ry co l

um n an d in p a rt b y ra d ia tio n fro m w a te r w h ich h as b ecom e h o t in th e r e c tify in g condenser.

T h u s th e h o t liq u id en ters th e p rim a ry colu m n and is d isch arg e d on to th e d o u b le b o ilin g ch am b ers w here th e v o la tile p o rtio n s are v a p o riz e d w h ile th e residues' p ass d o w n w ard th ro u g h a tra p , or a u to m a tic d isch arge.

T h e v a p o rs n ex t p ass in to an en clo sed a n n u lar rin g in th e p reh e ater, th e h e a v ie r p o rtio n s condense w hile th e lig h te r pass o v e r in to th e r e c tify in g ch am b er, are su b je c te d to re p e a te d co n d e n sa tio n and v a p o riz a tio n and fin a lly c o n s titu te th e h igh p ro o f alcohol.

S te a m is d raw n fro m th e h e a tin g sy ste m , passes th ro u g h a su p erh ea ter and th e n ce in to a pressure

> Th is Jo u r n a l, 4 , 609 (1912).

D e c ., 1913 T H E J O U R N A L O F 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 I O I Ç

ADDRLSSLS

B IO C H E M IS T R Y

1

B y Ca r l L . Al s b e r g

I did n o t com e to R och ester w ith the intention of m aking a speech, b u t find— I am so rry to s a y—-that P rof. Cham bers exp ects m e to ta lk . H e m ade th e requ est— or, shall I say, dem and— as w e cam e to th is room . I find th a t I am driven to the u su al refuge of th ose w h o h a v e to sp eak when th e y w ould ra th er be silen t— th a t is, I w ill ta k e refuge in the h isto ry of m y su b ject.

T h is su b je c t has, I th in k, som e general in terest because orig

in a lly no v e r y definite d istin ction w a s m ade betw een biochem istry and a n y o th er k in d of ch em istry. One of th e first real bioch em ists w as L avoisier, w h om all m atter, w h ether livin g or dead, in terested. H e perform ed the first calorim etric experi

m ents. H e w as th e in ve n to r of th e ice calorim eter, and show ed th a t anim al h e a t w a s th e resu lt of oxidation. A ll the chem ists of t h a t gen eration , and the im m ed iately succeeding one did biochem ical w o rk . I need o n ly cite L iebig, w ho is perhaps in som e w a y s th e grea te st of all biochem ists. U n fo rtu n ately, a b o u t th e la tte r p a rt of L ie b ig ’s life chem ists lo st in terest in bioch em istry. T h is w as due v e r y la rg e ly to th e sudden and

1 C h airm a n ’s address, Biological C h em istry Section, 48th m eeting, A. C. S., R o ch ester, S e p te m b e r 8 -1 2 , 1913.

trem endous d evelo p m en t of organic chem istry, w h ich w as b rou gh t a b o u t b y th e discoveries of m en like H ofm ann and K e k u le . I t w as so easy to m ak e n ew sy n th e tic substances, and th ere b y gain a so rt of im m ortality, even th ou gh the m ain result of p u ttin g a chlorine atom here and a brom ine atom there w a s to fill u p B eilstein . In consequence, th orou gh ly train ed chem ists did n ot b u sy them selves w ith su b jects th a t w ere rea lly im p o rtan t in the elucidation of th a t m a tter w h ich is fou nd in liv in g organism s, and w h ich form s th e physiological b asis of life. T h e scientists in b io log y and m edicine needed such in

form ation. T h e chem ists did n o t g iv e it to them . C on se

q u en tly, p hysician s and p hysiologists w ho w ere ill-equipped for chem ical research w ere forced to c a rry forw ard th e w o rk of b io chem istry. T h o u g h th e n et result of th eir w o rk m ade d e

cid ed ly for progress, o n ly too often it created confusion and artificial difficulties. E v e n the best biochem ists of those d a y s m ake us w onder w h y th e y did n o t pursue th eir chem ical in ve sti

gations as far as th e chem ical m ethods of th a t d a y w ould per

m it. T h e answ er is, I th in k in m a n y cases, th a t th e y w ere n ot real chem ists b u t physiologists w ith a chem ical veneer. F o r tu n ately , this h as been ch ang ing during the past decade, la rg e ly ow ing to th e w o rk of E m il F ischer. W hile w e recognize in him a m aster of chem ical technique, w e m a y be certain th a t in a measure, a t a n y rate, th e preem inent position w h ich he occupies reg u la to r. F o r ex p erim e n ta l w o rk d ealin g w ith th e AN IM PR O V E D L A B O R A T O R Y BU RN ER p ro d u ctio n of e th y l alcoh o l fro m su lfite w aste liqu o r By Chas p Fox

R eceived S e p te m b e r 16, 1913

In lab o rato rie s w here air cu rren ts are trou b lesom e, a cylin d rica l w in d shield, in d ep en d en t of th e burner, is o ften em p lo yed . F o r use w ith a n y of th e com m on ty p e s of la b o r a to ry burners,

in th e a cco m p a n yin g p h o to grap h is m uch m ore co n ven ien t.

I t consists of an in v e rte d sheet m etal cone 5 inches long, 2 inches in d iam eter a t b o tto m , and 3 inches a t to p , and su p p o rted b y a 3-arm ed fram e a tta ch e d to th e burn er tu b e.

B y m a k in g th e su p p o rt su fficien tly rigid th e trian gle h old in g th e cru cib le in ash d ete rm in atio n s and the ga u ze w hen h e a tin g sm all b eake rs m a y b e p laced d ire ctly across th e to p of th e shield.

th e a tta ch m e n t show n

Fig. 2

an d of m e th y l alcoh o l m ixtu res su ita b le for denaturing pu rpo ses, a ste am pressure of less th a n 5 pounds was fo u n d efficient.

La b o r a t o r y o p In d u s t r ia l Ch e m is t r y

Un iv e r s it y o p Wa s h in g t o n, Se a t t l e

A n y tin sm ith can fash ion and a tta c h th e shield, usin g for th e 3-arm ed fram e an o rd in a ry ch im n ey su p p o rt (E . & A ., N o. 2613 or S arge n t, N o.

1080).

T h is t y p e of b u rn er, as im p ro ve d , has been fou n d v e r y useful in lig h t la b o ra to ry w o rk. T h e im p ro v e m ent h as been in use sev eral y e a rs and, as fa r as kn ow n , is origin al.

Ak r o n, Oh io

1020 T H E J O U R N A L O F 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 V o l. 5, N o. 12 am ong th e chem ists of his tim e is due to his clear conception

of the re a lly m ost im p o rtan t w o rk in organic ch em istry along biochem ical lines. F o rtu n a te ly , m ore and m ore organic chem ists are follow ing in his footsteps, and are d evotin g th eir a tte n tion to su bstan ces w h ich occur in liv in g things. I w ish here to m ak e a plea for more of this sort of w o rk in A m erica. I b elieve th a t the rew ard s and recognition for kn ow ledge o f chem istry ap p lied in biochem istry' are great, because th e w o rk of th e b io chem ist w ill be ap p lau ded n o t m erely b y chem ists, b u t also b y zoologists, b o tan ists and physicians. A b ioch em ist has a w id er audience because his w o rk presents a m ore general a p peal th an th e w o rk of organic chem ists upon such su b je cts as dyestu ffs and th e like. F u rth er, I w ish to point o u t th e v a lu e of in struction in allied su bjects. N o t e v e ry organic chem ist can successfu lly a tta c k all biochem ical problem s. Besides his organic chem istry, o th er experience in p hysiology, and ab o v e all, experience in dealing w ith su bstan ces w h ich do n o t cry stallize is necessary. In m a n y cases it is difficult to con d u ct biochem ical research because th e b ioch em ist m u st v e r y freq u en tly begin w ith th e sm ears, w h ich the organ ic chem ist consigns p referab ly to th e slop jar. W hile the things w h ich w ill n o t crystallize in terest th e organic chem ist less, th e y are the v e r y classes of su bstan ces w ith w h ich the biochem ist m u st deal. G re a t care, grea t patience and a know led ge of colloids are required of th e organic chem ist w h o w ishes to w o rk in bioch em istry, b u t I feel confid ent th a t th e rew ard for such m en is great, n o t m erely in pure science, b u t also in th e industries and in the arts.

T h e h isto ry of bio ch em istry in A m erica is sim ilar to th a t abroad. In A m erica it develop ed first in the seven ties and eighties in the m edical schools of th e co u n try ; and, a t t h a t tim e, it w as con trolled b y p h ysician s and physiologists abroad. T h e su b je c t w as n arrow ed to th e consid eration of bio ch em istry as a ffect

ing th e life of m an ; th a t is to say, th e chem ical side of p h ysio

lo gical processes of th e hum an b o d y togeth er w ith such con siderations of b acteriological chem istry as a ffect m an in h ealth and in disease. T h is phase of bioch em istry is cared for v e r y a d e q u a te ly and a cc ep ta b ly b y th e A m erican S o c iety of B iolo gical C hem ists, th e first biochem ical so ciety to be form ed in A m erica.

T h e phases of bioch em istry w h ich th e A m erican C hem ical S o c ie ty can v e r y n a tu ra lly e xp ect to encourage are qu ite dis

tin c t from the aim s of the A m erican S o c iety of B iolo gical C h e m ists. O u r usefulness w ill include the bio ch em istry affectin g agriculture, p h y to ch e m istry in p articular, and such in dustrial processes as are based upon biochem ical reactions. F o r ex

am ple, th e m ore e x a ct stu d y of the chem ical com position of fruits, grains, and food products. I t m u st be a d m itted th at, a t present, w e kn ow o n ly those chem ical substances occurring in considerable am ou n ts in such im p o rta n t grains as w h ea t and corn. T h e m inor con stituen ts in grain s of m uch im portan ce h a v e n ot been identified w ith exactness. I f w e consider grain s of less im portance even th is degree of kn ow led ge can n o t be claim ed.

Som e of our m ost im p o rtan t m odern industries, like those d ealing w ith starch, artificial fabrics, leath er tan nin g m aterials, glue and gelatin, m e a t p ack in g and th e flour m illin g in du stry require biochem ists, and w e are now train in g m en to deal w ith such p ractical problem s.

If ou r so ciety confines itself to the a ctiv itie s a lre ad y m en

tioned, there still rem ains a w ide field of bio ch em istry uncared for, th e b io ch em istry of th e low er anim als. T h is p a rt of the bioch em ical w o rk w ill becom e a p a rt of the w o rk in the zoological societies of th e co u n try. M y v iew is th a t three societies of biolog ical chem istry can w ell exist in A m erica w ith o u t com petin g in a n y w a y , each one carin g for a specific need. T h ese w ould

W dokumencie The Journal of Industrial and Engineering Chemistry, Vol. 5, No. 12 (Stron 53-60)