Document 2J0apx8Xdnz8nvbmX69waQ6e7
- **fLv*y>'
Centra.! Hesearch Department Dayton 7, Ohio
October 12, 1948
_- An- niasto n
\jiy4El Sio^pHBjSiT^
.
W, +*1 v t
5,^Tf
5'g. 4);&v
ANALYSIS OF CRUDE BIPHENYL
y-h* * * * -Su ,v i & y
*> ~
,-ri
abMffiftP* ^f'%lo.n mi Afiaean* for analysing bVua* blp! n_ylaixture.i : ', for biphenyl, ortho-, meta-, and para- diphenylbensen* ;;
. *, *.
&>> 1 ! t*_ <%
. ,v has boon thoroughly Investigated. . 01 these two lines ,'
' - of investigation, only the ultraviolet proved auecesi*:;:^^,A^^
' ful. The results of each are described below* . ' . > '
<
*,, i ' * v '
' , 1 s`. / ^
i a infrared Absorption * ,
- 't/, "
*\ * * '
1
"
>-
% H- ^
. * J *' "
,' f, * *
*y 1
'r
; .-. The major difficulty ehconhterda- meino of 8/6/48 -
was finding a solvent in which all components would be \f 'MMff
Aolu&le to; the extent o& 2CW|0$. jittempts to usethickSr
absorption cells in conjunction with CCI4 and CSo as sol- '
vents proved unsuccessful! the interference of the solvent
became more pronounced as the cell thickness was increased*
Since there was no apparent solution to this problem, the
use of infrared was abandoned.
Ultraviolet Absorption
<
'll
* , ^r-1 S-*
1 Biphenyl, ortho-, meta-, and para-diphenylben-
senes have absorption bands in the ultraviolet with maxima >
at25Q mu, 230 mu, 250 mu, And 280 mu, respectively. (Fig. 1)*
These spectra, aS well as all subsequent measurements, were v
measured on the Beckman Quarts Spectrophotometer, Biphenyl
and meta-diphenylbenzene each have their absorption bands
at 250 mu. Because of this interference an analysis was
developed for only the diphenylbenzene isomers. In those
cases where the suspected biphenyl concentration Is greater
than 2$, some means of separation, Such as distillation or
chromatographic separation, must be resorted to.
-
\
,, ....... ...... The method of siiixultaneous equations was adopted v,-?,
1*
for The
this analysis sihCe two>qr more components are present* steps involved in the development of, this method are'\
v
folio*.|
Iv *^ J i
(1) . Determination of the optimum cbneentratlon for each
component which would give an optical density (D)
between 0.3 and 0,7 at each components key absorption band. This concentration was 0,0004$ for all components,
*- '
`
'
(2) . Preparation of 0.0004$ C2H5OH solutions of each component from 0.1$ CCI4 solutions. A 0.4$ solu
tion of CGI4 ln CgHgOH serves as a blank.
oSV\, 330822
STLCOPCB4077466
.V
Dayton, Chib
October 12, 1948
R, J* Slocombe
Anniston
Page -2-
; <'*%- ?
.Mc..o.ue..m.<a.:.>.sp..u*o--r"nekerm'net nert*t*0*8#3it0-h'w,eSjou5*u.0pf\t*i,,cmv adT lr^^\irsd-2-i*'--'a8-ee,*".r,0v***n.*j'-_'sm.T*vtitu<i e,'.futss*`*fl\ongr
*
* * * - *&*"'*' eaoh t?S\
i0..wu
t*' * 4 *'
Vy.:'
**
(4). Calculation of the following Extinction coeffi-
cients using the equation !DEx, where B is the
extinction coefficient, D the optical density* and
the concentration in railTi grams/100 mil , -
.v ~ ;,-:'/ . \.j
v-'- *-y- . . . v. >.,:. . .y, .-- i--^ - - - - , . v -.*.
- y ;:vy-
Bi* the extinction coefficient Of ortho- at 30 wu
m
&,. the extinction coefficient of meta- at 830 mu E, the extinction coefficient of pard- at .230 mu
iv^r
:j
' ,' ' t_ ;
y.
B,, the extinction coefficient of ortho- at 250 isu
Eg, the extinction coefficient Of meta- at 250 mu , y
Eg the extinction coefficient pf ;para-' at 250 uni
Ey, the extinction coefficient of ortho- at 280 mu
Eg, the extinction coefficient of meta- at 280 mu
=9* the extinction coefficient of para- at 280 mu.,
y :y 'y^y.yyy Vyy yy . y yyv -yy, yyyy;y- - ' * y . y--yv yy.Vyy y ^yyy'y'yy.?^
(5), In a mixture the optical density at any one wave-. ^
length Is equal to the sum of the optical densl* # /
ties of each component at that, wavelength. This state- H
ment is the basis of the method and JLs responsible for ij
the following set of simultaneous equations!
.
Da Hi x 4 Bgy %* Db * B4x 4 Egy 4 Sgs
i> * 7* 4 s8y 4 e9*
4,.-*
where
M&?' u
y yWyyy yyy.y- ' y
- <' .'-.y--V:' K-''' ; %*
'tv1..,-,.'- .-...-s'-
. 5$&ys'. Dfi a`optical density of mixture at 230 mu SfclL s optiEdl denaitf, 0f' mixture j&t 250 mu" :
................ I>0 optical density 'of mlxturs St 280 tttt ' ; r x * jag,/100 1V of ortho-dlphenylbensaiie
y a mg,/l00 ml, of meta-diphenylben*one
s mg,/l00 ml, of para-diphenylbenzene
Substituting the E values calculated In step (4)., and solving the equations for x, y, and 2,
DSW 330823
5-
f STLCOPCB4077467
Dayton, Ohio
B, J. Sloooidac Anniston
October 12* 1048 Page -3-
The analysis of a mixture Involves the follow-
Ing steps*
A-^`
(1)# 'Weigha 0.1 gm. sample ( 1 mg.) into a lOb ail* > volumetric flask and dilute to the mark with CCl^.
(8)i Prepare a 0.0004JC CgHgOH solution from the O.ljt
solution*
"% ' j-V" *V
\/
V*
1
'
(3). Measure the optical 'density at 830, 850, and 880
y mu in 10 mm. quarts absorption cells using a 0.'
CGI4 solution in OgHgOH in the reference cell* : `
(4). Substitute these values in equations '(d)., (e), and (f) and solve for x, y, and 2.
............. ,.
100 x/0.4 % concentration of *:----- " , ' ,
ortho-* etc# '
''
" The results obtained for four synthetic mix-t,
'i
tures are shown in the/ table below*- ]
|?
*
Sample
Component a Present
jt Found
% Error
#1 ortho- . 85.0
meta--
50*0
para-
85.0
84.8
47.3 84*8
*0.8 -5.4
-3.8
ortho-
25.0
mta-
,/>. 435*0 &?**'**
'^para^^ljl5 450*0^
86.7 24*3
48.1
46.8 , *8-84
3 8 4.-;
} ^ - V v44v: <K/}^ #4
orthometaV para- .
orthometa para-
,
85.0 75.0
84.3 76.3
s' l VJ
-2.8 fl,7
Averaging the percent errors for each com ponent, an expected accuracy (based on amount present) of 43.2# ortho-, - 3.7^ meta, and fl.8j para- is obtained.
DSW 330824
STLCOPCB4077468
-. v `.
Dayton, Ohio
H* j, Slo combe Anniston
October 12, 1948 Page -4-
ortho*. ' v . '..
3.0#
?''v erneta-, '.. ;:" ;
60.8
para-
.; * 21.5
biphenyl
ttoHigher boiler
12.9
.
Total
... ' >0.0,0.
/\
1
o Includes biphenyl
X
a* Obtained by difference of total from 100#
11.9# 53.7 83.9
1.0 9.5
100*0
' A Single analysis can be convicted in less than 30 minutes*
V VA -
v **
IV-
..-.. ......__ ..Although, .the -method. 1*. based on - the assump-----*.
tlon that the higher boilers will not interfere. It '
might be wise to check this point In view of the dif-
ferencea in the analysis of Santowax B obtained by the
two methods above* If you have some of the higher boiler
material available, we shall* be glad to measure its ul-
travioiet absorption spectrum*
X
suggestions as to possible methods of separating biphenyl from meta- diphenylbenzene would be most welcome* However, if the biphenyl concentration
is not to be too high, we need not worry ourselves about this problem* ' ;'
.
rV r`V We sincerely kopesthat! this method of anaf.r'
.r }*bU '4u.^v
40 .#M. niiiik &Mk
X. v -'' *
A~ '
*
o\
* f'-f <-?$ .
V ... - V ^ t H t
')$%;&' 'S:'v*AS '?<#*?
i ' " " ' '
.,
*-'4 '. . ,: -
-S'
Donald E. Beasecker Pn
0SXN 330825
STLCOPCB4077469
DSW 330826