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METHOD FOR THE DETERMINATION OF FATTY MATTER IN SOAPS I. R. WISHNICK ARMOUR INSTITUTE OF TECHNOLOGY 19 14 668. 1 W76

METHOD FOR THE DETERMINATION

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Page 1: METHOD FOR THE DETERMINATION

METHOD FOR THE DETERMINATION OF

FATTY MATTER IN SOAPS

I. R. WISHNICK

ARMOUR INSTITUTE OF TECHNOLOGY

19 14

668. 1

W76

Page 2: METHOD FOR THE DETERMINATION

Illinois Institute

of Technoiogy

UNIVERSITY LIBRARIES

Page 3: METHOD FOR THE DETERMINATION

AT 355Wishnick, I. R.A new method for thedetermination of total

For Use in Library Only

Page 4: METHOD FOR THE DETERMINATION
Page 5: METHOD FOR THE DETERMINATION
Page 6: METHOD FOR THE DETERMINATION
Page 7: METHOD FOR THE DETERMINATION

A NEW METHOD FOR THE DEtEBMINATION

OF TOTAL FAxiy ivIATT^E liJ SO/PS.

A THESIS

PKESEivTED BY

I.BOBEET WISHKICK

TO THE

PP.ESIDSUT AKD FACULTY

OF

APidOUE IKSTITUIE OF TECmJOLOGY

FOE THE DEGREE OF

BACHT^LOP OF SCIEiJCE IK CHEniCAL EKGIwEEFawG.

HAVIiNG COMPLETED TH^ ^E^CRIB^D CCfiJESi^

OF STTTDY IN

CHEJnCAL ^NGIKE^EIKGi

MAY -1914. PAUL V. GAlVffJ LIBRARY35 WEST 33RD STREET

^„„„^„^ 'HICAGO. IL 6061^

^:^<^ "-^--t^^r^-.^^cjt^

r"

c

Page 8: METHOD FOR THE DETERMINATION

.i»'

A

i^ - W-' ~" A'i '•!

«J

.A

• -«<>

.H**!At It

Page 9: METHOD FOR THE DETERMINATION

.1.

INTEODIICTION.

Soaps ar? eir.ply mixtur-*" o^ the alkali

salts of the fatty acids. Th» process of

effecting combination of the -^atty acids with

the alkalies to farm the alVaii salts is ter-

med Baponification or soap boiling. It is

often necessary to know the amonnt of fatty

acids TThich were used in making the soap.

The pres'^nt method employed to determine the

fatty acids is a very teiious one and require «5

an experienced analyst to ob+"in check results.

It therefore, seemed practical to find a method

which was shorter ani simrjler, and accordingly,

the following work was undertaken.

EXPERII^NTAL.

The presi^nt recognized method of det-rmin-

ing total fatt3^ m.at^er in soaps consists essen-

tially of the following: a 10 grami saapi* of the

aoap ig transferred to a 500 cc. beaker, and dis-

solved in hot wat*r. Anv in-'oluble residue is

filtered off. Sulphuric acid is added to liberate

the fatty acids and the mat-rial is heated on the

Page 10: METHOD FOR THE DETERMINATION

• if* *0

.i'»c Ti f-»«" •It** .«f'"^l^ •tx'<

.J

flt*"^- *? 'c

"<? *!:o •* 1^' 'i . t»-o£; ' *o r:A';l*

on

*.

* "'^nti. ' Xo?

Page 11: METHOD FOR THE DETERMINATION

.2.

water bath until th« fatty acids separate in a

clsan laysT at th? top. At this point it is

advisable to add 5 grams of paraffin© so th^t

a firm cak« of the fats Trill b? -^orTned. Th#

weight of paraffin* is lat-r d«duct«d froTn th«

total w«iffht to ffiv« tfe« weight of fatty acids.

After th» paraffin* has mtlted, the beaker is

removed fror. the water >>ath and the fats allowed

to solidify. Remove the cake of paraf-^ine, and

fatty acids, wash it free of any ^ulphtiric acid,

and place it into a weighed b3aVer. The washings

contain sone •''ats.. ^^^hich are removed by a double

extraction with petroleTLTi ether. The ether extract

is pla:;ed in the beaker containing the cake of

f?tt7 ira-^ter, anf. the ^ther is evaporated off

over the water bath. The beaker is then placed

into a dr'^ing oven and dried at 100°0 to remove

any moisture. The drying must be done carefully

because if heated too high, the fats will decom-

pose, wheraas if too low a temperature is used

the moisture will not be roroved. Obtain the

weight of the whole and subti^.ct the weight of

the beaker and paraffine tc get the weight of

fatty acids in the soap.

Page 12: METHOD FOR THE DETERMINATION

^« •* • »• OffJ

Page 13: METHOD FOR THE DETERMINATION

.3.

The abovs method for toal fatty matter in

soaps has its drawbacks, viz,.l- The tir:e reouired

to complete the detarmination is V'^ry long be-

cause of the necessary- delay's 'T'hile drying the

fats to constant weight. (2) It is very difficult

to tell jnst how long the fats must be dried

be'^ore the fiaal weighing, and unless, one has

had some experieace with this he is liable to

male© an error here.

In order to overcome the objDction? to the

regular method Mr. John J. Schor^rrer suggested

that the Babcook method for the determiuat ion of

fats in milk might be successfully applied to

determine fats in soaps, and following his suggest-

ion the following work was undertaken:

Various samples of liquid and solid soaps

were analyzed by the present amd also by the pro-

posed method. The present method used has already

been described. The proposed method tried is very

similar to the ordinary Babcock method for fats

iH milk. It is as follows:

Use 18 gram samples for liquid soaps and 4.5

gram, samples for the solid soaps. This is ione so

that the fats liberated can be read easily on the

Page 14: METHOD FOR THE DETERMINATION

fli

1^ ' ^ l^jK /< ^ J?**" r**** <u,(#' n rtf. r <mr^ 4->» ' ; ' i t ' ^ i^ -?

»

• fTj c

'0 ...-

t-f^OP t -/

•11 Cot «i »*«'^ f-a

' if" !. .ff ^' 'Tcr • :ix-^"oi -'i^*''* * ^'*' not

Page 15: METHOD FOR THE DETERMINATION

.4.

necks of Babcock bottles. The readimg obtained

with liquid soaps gives the per cent, of fats

directly while V7ith the soaps wh^re 4.5 gram

samples were used, the reading must be multi-

plied by four to give the per cent. Transfer

the liquid soaps directly to the bottles Tvhile

the solid soaps are first dissolved in hot

water and theji transferred. Sulphuric acid is

BOW added ia sufficient quantity to liberate

the fatty acids, warm the bottles in hot water

for a w'^-ile and centrif^i.ge thex for ^our mintites

Add hot water to bring the fats o« the neck and

centrifuge again -^or one minute. Remove the

bottles '•lid read the per cent, of f?ts on the

neck while the fat is still "^arm.

The following table shows the results ob-

tained by the two methods, using 18 gram ox-

fractions of 18 gram samples in the proposed

method:

Page 16: METHOD FOR THE DETERMINATION

-^ '^ n %i» ••» riK

^ k. *.,

*rf» «>-^ wf* to .

> *

'"J I. i ' " n J

fft «i •«! •*» *f ft t

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Page 17: METHOD FOR THE DETERMINATION

.5.

ho

cot)Ooin-<4«ooocoicco<D ca<!;• so LO to « u: lo 00 o c '-' <>2 «-* CQ k: ifl tofa: •• •

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r.^ iH rH rH «-» si' CO J- >- t~~ ^ If <C tt: t£) t •

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+'OrHrH,H-l-»«:}IC0t-t>-t^CDir'tD'©'X) "^+>p.« or ^^ CO C3 50 <M -J* <X) ^ Oi Cvl C^ ^ * CO C IN CO& •••.

>. * ca ID "^ a. 00 CO 'i' i>- tc r-i o 00 fv- ^ r-«

+i r-lrHrHrH.H-sJIC0t~C-J>-tDU3'^"X>«; tJ»

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l-l Vt>-«oci'5ioacvjC'-ttoir!-^c-<ooc »j«

tJ -t-- in 00 c; o c lo o- CI a> oi 00 'X) '-' t^ c~ ch3 «OO a, T' -^ r-( r^t -J< 00 CO <D »0 to f r-t fH r-t O- O UTJ

•< t O rH «H ^ .H -i ^ C-- C- C>- t^ <f Lf J>- tC !^ -^

0) p c^ o "O cr. K. CO c to «> CO o c- o o f. isPhS f>a <0 IN 00 00 C\ C-- CO to ID to >H Cj •^ c '^

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ti!. D- C5 X) IC lO t^ O O O <X) O K tr <M is<D f-t .^3 L( } C- 00 O ^ CJ> 03 If rj" If C Oa >-l K)((;.•••••.•.•...«• «

•^fM-^JOC-QOOlC^-^tOr-lr-ICO^C •«*

»Hr-l,-<rHr-lTjil>.C^.l>.>.<Omj>-tOt- T^1

r-i i^ to -^ la 4^ «-lM

pH to 43 E

o rt ^ +3 ^ fe f^n: o« c = s: ^-1 > ^ +3 (D

^ pi b^HJ X m 1 ^^ -H o oT( pSse£S430M<D) oHfJn •r^Bo* V E O <D V bDtH cr /. c br43•H n-i OM>^-H-Ha>-PEEOMt^H -3 :q < n CO >J « ix, (0 «t < trj ©

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•Hw»CTrHio«ot-oO(J>0'-'ca»Cr}'m<o05 rH l-H 1-H (—•<—( r-< r-<

Page 18: METHOD FOR THE DETERMINATION

I;

C^ 4k 40 4^ flft V M t

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» -! t a t' » 0'

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Page 19: METHOD FOR THE DETERMINATION

.b.

From the results im xable I it Ib seea

that the erroTB involved are alto?e-cher too

great and that uo defi»ite 3o«stamt cam be

applied ?irhich would irake the resiilts obtaime-'.

by the -proposed method sheclr with those of the

regular niethod. It appears thereforej that the

proposed method is a failure. However upon a

further study of the subject ^»i a critical in-

spection of the results so-iethinp- '^^as discovered

which led to a succeesfu.! solution o-^ the rrob-

len. It was noted tbat the Babcock bottles are

graduated to read the per cent, o-^ Butter fats

only; and since the -^at? found in soaps have a

different specific gravity than the butter fat,

it is natural that th-^ readings -"ot'ld be wrong.

To overcome this difference in specific oryavi-

tles it is necessary to know the specific era-

vities o-^ the fats in the soa-^s so that allow-

ance can be made -^or it. Acor'^ia^ly . the spe-

cific gravities o-'' the varior-.s fatty acids in

the soaps was determined as follows:

Pine? into a beaker a sufficient quantity

of soap to gi.¥e enoi-'^h fatty acids to •''ili the

tube for the float used with the West-^h^i balance.

Page 20: METHOD FOR THE DETERMINATION

~J.Ai - <'

"t

ftt i

• • *' -.-« - -+<

t^^f •:

•*x'

.< JC •' u '

t^ *t'^ Ot : O'- "

•'*

Page 21: METHOD FOR THE DETERMINATION

. I

,

Dissolve the soap im hot water, and add sul-

phuric acid to liberate the fatty acids. Waxin

the beaker until the fata separate i» a clean

layar at the top. Pun the material into a warm

separatinp' funnel, run of* th'=' heavier liquid

and finally allow the fate to run into the West-

phal tube. It is necessary '^hile t^kinp; the spe-

cific gravity to ^eep the fats perfentlv fluid.

This is done by having the tube imnersed in hbt

water. Keep a record o:'' the temperature at which

the specific gravity is d^+errined.

Kavin? deterr.ined all the specific gravi-

ties of the fatty acids in th^ soaps, proceed

to calculate the weicrhts of sample?! which ought

to give the correct per cent of fat? direct Iv

with the use of the Babcock bottle. These weights

are calculated as follows:

We know that th»» speci-^ic volume is invers-

ley proportional to the specific gravity. There-

fore, if the fatty acid has a greater specific

gx'avity than Bu'-ter fat, the volum-- occupied

by an equil w«i?ht of fatty acid will be less

than that occupied by btitter fat. In order to

allow for this a lar?rer size sample must be u-ed.

Page 22: METHOD FOR THE DETERMINATION

•rr • 'fl^J

'• r A

"J.

Page 23: METHOD FOR THE DETERMINATION

.8.

The 8iae of sampl© is obtained by Tmiltiplying

the ratio of the sT^ecl-^i'? ffravitie* of the

fatty acid to Butter fat by 16 or the norrnal

weight of sample tised in Butter fat deterrrina-

tions. ThiTS, if a certain fattv acid hao a

specific ftravifv of ,9"^ at 4<^°C . i^rhile BTitter

fat has r. specific ?:ravitv of ,9'"6 -^t 40°C!,

the calculated wei-rht of sample is jQSxlS'-

.90618.4768 ?ranii?.

If the speci-^ic gravity of the P^?.tty acid

is less th:in Butter fat a corre^pondinp: de-

crease in th* siz^e of snmple will bo necessary.

The ^ollowinp' t?ble showf=? the various spe-

cific gravities of the fatty acids, '^nd ?ives

the calculated wei^h+ of sami les to be used in

each case. It was asgun:ed that the specific

gravity of Bntt-^r fat was .906 at 40°C and

that a correction of .000617 be allow-d for

each 1°C for the sp*cific gravity of Butter fat.

Page 24: METHOD FOR THE DETERMINATION

»f«t

. *?«

'n n

f* ?.

~if-» -,

f* ^(n »

;-.'^ ' ~t'(\ f;

, 3f*T 'i•j riTj i:? ' u 4 ff"

Page 25: METHOD FOR THE DETERMINATION

.s.

T?

Page 26: METHOD FOR THE DETERMINATION

.J s» <

a J)

1 m

s 0-4

o

!•»

*f « < •><:; ^i 1 J.«* • •

.; *> (,i >\£ III

It

Page 27: METHOD FOR THE DETERMINATION

.iO,

On a comparison o"^ the per cent error in

table I with the sin:e of sanples calculated in

Table II, it i% evident why those errors appear

thus. We note that there is no de-^inite variation

in the error an": al?^ no de-^init'=' variation in

the sise of sar^'-les to '^^e "se % This is due "-o

the vari^'tions in the speci:^ic gravities of the

fatty acids in th^ so^ps. It is therefore, im-

possible to obt'^in =1 definite oainple which cau

be Tised ''or ail so^^s to -^i^-e correct resT^lts,

but the weight to be tised must be 'let ermine-^, for

each separat-^lv. Another point that can be not-

iced from the two tables is that th-s soaps which

rtj-n hi?h by the proiiosed ^etiiod are composed of

fatty acids w">^ose specific gravities ?-re lower

than that of b'jtter fats. This is '•^hct is to be

expected because the fatty acids havin?, a lower

specific gravity willhave ?. greater specific

volume ?.nd will there-Por^^ ?ive too hi»h a reaiing»

In order to correct 'or -f^his it v'ili be seen that

the calculated weight of sam.plcs in s'-'Ch cases is

less the.n 18 grms. which is the norm^.l weight to

bo ueed for butter fats. In tho«e instance* where

Page 28: METHOD FOR THE DETERMINATION

t->n ^ rf , <- .» -r 1 + -. •*•* /•\ .•• 4 ."j * •"'r <-'^- f. « *?' **

^0 •»••<» ''"»«?'•• • •>,«*"' ' rf* ""f*^^* f S* tt'lt

«*ff n* mt 1 ' ?«'^»

. "o n-.^s -{'"*t

-, ,-,j. - • » *r ***-t' f"-f-», "iff

Page 29: METHOD FOR THE DETERMINATION

.11.

the specific gravities are greater than bTitter

fat, th° re^'ult" in the Table I, show th-Jt the

proposed method gives low results, and the cal-

culated w?in:ht of samples to be used are all

more than 18 ?rms,

iJow, proceeded to fini out 'Whether the

above calculated weifrhts o-^ samples scttially

e-ive the correct ^;.er cent, o-'' ^its. Accordingly

repeated the analysis of each soap for toal

•'^atty Tr.dtter by the proposed method using tha

calculated weights of samples ep'-h time. The

'ollowlng reaults were obtained this ti:;e:

Page 30: METHOD FOR THE DETERMINATION
Page 31: METHOD FOR THE DETERMINATION

Ofit)u^n.\2o o o lo to C oo c om o c <# oV ri r-i -• to c ca o •-• ca c (.\j to oo m th o•H

O C3 C> O O O O O o o o oo oo oh,o oooooooocoooo ooC JO o cQ o 00 <\i cv3 lo 00 00 ro CO ca ca 00 toH in CO CO 'i) If? to if^ 'i* -^ y3 lo rH jn in <^ CD

c• a;

to+^at

43 _^

MO© „M oec x>p>-^coooooootoooc\j'30ooca'*M O

^1 Pt-^ rH i:jt ro r- 00 O"; cvj 'i* to r-l t-« r-t CO c -^t! *) o —• '-• rH 'H 'H * js ^- i>- IN CD in j>- vO r- •^

< cEH tUJ

* 03 C O O lir: fO c c> c c c ir O O X) O•-I W C^ CO Ol 00 <.NJ CO Oi C3 <D CD li' C »'J O '*:i

b itJ« tH r}l 10 ^ iX) 0» n rjl to rH .-I r-« 0^ C ^C M -H rH r-« r^ «;}< Pi {^ £^ J> CO XI i> CD t»- ^

p4i-< i.-vJtC-^int0c^000iOrH,-\J«O-5flCCDof lHr-<rH-lf-l«-tr-«o

Page 32: METHOD FOR THE DETERMINATION

<*•'. a i» D*. <tI .'3

u «*> -<

Page 33: METHOD FOR THE DETERMINATION

.13.

Discussion OF EEPULi'S with PE^O/.UtlOI^P?.

It is evident from an examination of the

above results that the proposed method is suc-

cossfii.l provided the correct wei~hts of samples

be calculated 'rom the deterr.in2.t10n of the spe-

cific p-ravities of th^ various fatty acids. The

results from soaps #12, 15 « 14 are somewhat of"'',

but, I believe that this is not ?. -^ault of the

method but that it is iue to th" character of the

soaps. Numbers 12, IS 6c 14 repref»»nt the laundiy

soaps; Fels-wSLptha, St^r, & Amber, which '"ontslned

a lot of resinous '""terisl end qvinn which hindered

the clean liberation of the •^'atty acid on the ad-

dition of sulphuric acid.

Some tro^ible wae had with most of th* laund-

ry soaps du* to the lar^e s^-^^unt of insoluble

material in the- and also to the presence of frums

which prevented the ^stisfactory liberation of the

fatty acids. This difficultv is overcom* by usiner

the alcohol extracts *'or fat determination. By

this mean*! the insoluble mat*ricl -^nd f^rms are

removed from th* sphere of action end the result

is a clean separation of the fatty acids. The use

of the al'^ohol e^tr^ct does not increase the time

appreciably, nor does it increase to s.ny extent

Page 34: METHOD FOR THE DETERMINATION

"^o ' f\ .'

,»^ ,, .. „ -f > '¥ '-f £.1 -> Ti r •

.':. "rf.'«!f -rff ^o fnoc ?•'

,c *r

f ^f ^

. i-

:* /t,x i i. I

**/> •^

•T "•O'" '^ "TT"

Page 35: METHOD FOR THE DETERMINATION

.14.

the Ipv.or needed for this determination as the

soi^ is usually evtracted with alcohol whf=>n an

analysis is rade on it for it* insoluble materi-

als and «o we can utilise thi«i extract "or the

fat deter'^inat ion. For very accurate work it

would b© necessary to take the readings on the

Babcock bottles r't the S3™9 tenr'er!=iture r?s that

at which the specific gravity was taVen, becanae

it was on that te=»sis that thw samples was calcu-

lated. However, for the ordinary analysis for

which this "^ethod is pro""osed the error involved

is sm?,ll ^-nou^h to bP noglectei as shown by the

following calculations:

Take ''or insfn^e soap ^ -^hose fatty acid

has a specific a-ravitv of .87^ at 50°C and i^hich

gave a per cent, o^ 72.8 at 5S°^. allowing .000 61

per 1°C for variation in sp. gr, w^ hrv? th9.t th?

sp. ?;r. of the fattv ^cid at B2°C s .8758.

Now "incc the specific volumes are inversely

proportional to the specific <?r9vities f'^e volume

or per cent, of fatty acid at ?>C°C, or the tem.per-

ature at -whi^h the s^^. gr. reading '"as taken is

expressed by X in the followino' equation:

Page 36: METHOD FOR THE DETERMINATION

ni •*! -<j"» ;r4 ,>*o ©re- at f.tV"-

f?'^'* 10' t*" - i[ tfa 1- "- r^ •rr- «!i'-

^ t-iff no *. *t

1- •»#>'•» vjt _TO^ ^^'

?-* Vl'-^VH'

!»«f

ff —mr f

rr-

f'l-r w ^ . fc -.'

.

'1.1*wo ^

* -^ « r .*^ r.'f*.

j'^rF ^0 ~V"=i« ^e ^ii-r'"j.'f '*'^i'

'?> t

Vf •T-'^flf

rtM5 ^« .^ ^^

'n " •i^i' •I"* • *^nm->-

Page 37: METHOD FOR THE DETERMINATION

.15.

.8738 s X

Solving for X w© have X - 72,,7io,

The above calculation "hows that for small

differences in the temperature at ^hich the two

readings "^re tiken, the error involved san be

neglected, but for lar?e differences the error

might be:^ome apprecioble. It is therefore, safer

to read the per cent at approx irately the same

teraperatiire that th? specific gravity is taken.

This I att?-.pted to do as closely as possible.

COKCLU^IOK.

The proposed r^ethod of determining total

fatty ratter in sor'."s is '"ithout "".oubt one that

can be depended upon to give results which are

accurate enough -^or ordinar'- cor.r.(»r4ial wor^'.

In cases where analysis must be turned out in

short order this rethod is -"^-r superior. It

ouo^ht to prove very useful in Ro?p fr'ctories

where the maxiufacturer already knowing the kind

of fat«> he uses know; his specific grravity and

therefore th-e weight of sampler to US'*, ani he

Page 38: METHOD FOR THE DETERMINATION
Page 39: METHOD FOR THE DETERMINATION

. xb<

can, thcr«, omit that part of the determination.

In cases where the sample supplied to be

analyzed is too small to yield s-u-P-^'icient fatty

acid to give enough r.aterial on which a specific

gravity determiniition can be ran, this n;ethod

could not be tised unless some idea be given as

to whether the *oap is made of ^ep'etable or

animal fats, when axi averag* weight mig?it be

used with fair accuracy although it is not ad-

visable to do so.

Page 40: METHOD FOR THE DETERMINATION

1 f " t. ~ - 4 £ ^r, ^ .

. am •'* ««" ooi f n

.Oft r y

Page 41: METHOD FOR THE DETERMINATION
Page 42: METHOD FOR THE DETERMINATION
Page 43: METHOD FOR THE DETERMINATION
Page 44: METHOD FOR THE DETERMINATION
Page 45: METHOD FOR THE DETERMINATION
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tm'Kii^vSi;

m'JMm

Imik

mmi

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