The design and construction of a photoelectric spectrophotometer for analytical research

Citation preview

NOTE TO USERS

T h is re productio n is the best copy available.

UMI

®

R eproduced with perm ission o f the copyright owner. F urther reproduction prohibited w itho ut perm ission.

Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.

'/

.

THE DESIGN AND CONSTRUCTION Of I PHOTOELECTRIC SPHJTROHIOTOMETER FOR ANALYTICAL llSIISet

W

A thesis Submitted to the Graduate Faculty

fo r th e S@p*s# o f DOCTOR OF PHILOSOPHY Major Subject t Analytical. 0HMl*tsy

B

■*.». *■--■ujK imi m M m

'at'

&pp%t@w&a$

.

4 4 'a _ T ^c a .« ^ ~ I) \ © L O 3© 5H

I m

State College

1942

R eproduced with perm ission o f the copyright owner. Further reproduction prohibited w ith o u t perm ission.

U M I N u m b e r: D P 1 2 1 0 6

IN F O R M A T IO N TO U SER S

T h e quality o f th is re productio n is d e p e n d e n t upon th e q uality o f th e copy subm itted. B roken o r in distinct print, colored or p o o r q u ality illustrations and photog ra phs, print ble ed-thro ugh, su b stand ard m argins, and im proper a lig n m e n t can a d ve rsely a ffe ct reproduction. In the unlike ly e ve n t th a t the a u th o r did not send a co m p le te m anuscript and th ere are m issing pages, th e se will be noted. A lso, if unauthorized cop yrig ht m aterial had to be rem oved, a note w ill indicate th e deletion.

UMI

®

UMI M icroform D P 12106 C o pyrigh t 2005 by P roQ uest Inform ation and Learning C om pany. A ll rights reserved. T his m icroform edition is protected a g ainst u nauth orized copying u n d e r Title 17, U nited S tates Code.

P ro Q ue st Inform ation and Learning C om pany 300 North Z eeb Road P.O. Box 1346 A nn A rbor, Ml 4 8 106 -1 346

R eproduced with perm ission o f the copyright owner. F urther reproduction prohibited w itho ut perm ission.

G lD 9 5

• VUSh"5Sd

- it ~

f o i

tmmm

or

? **« ■

f, INTRODUCTIOK* ,, , i i ,

mmximTM**

. ,. ...,

. *

, „

.,.,,,,

1

,

s

* ., , ,

A* fk# Apparatus, ,,,*

**.„*

6

1* fh# optical * ? « * « • • * * . * • » • • . . . * » # * • * » • 6

Tim measuring

a.

d

e

v

l

o

#

6

fr, tea monochromat or.., , 2. fh# amplifier,*

,

8

,

,

,

*

1

8

5* til# recorder*,

24

S , Operation of tit* & 8, l III, D

If, < t,

a I

H

s

S »

C C

a U

^

S

g l

S X

» . » * , • , t

S C

mmmm.

a

X W

C S

, ,,

.

.

,

2?

,

28

*

,.,,.......

33

«

*

38

*

,

.

* , , , , , 40

m

■ ft, fit,

mfBB,

4 7 4 4 1

43

J

R eproduced with perm ission o f the copyright owner. F urther reproduction prohibited w itho ut perm ission.

t ,

a m

s s w tM

SX* aatasea «f analytical afeaa&stiv *tt#t #»!»§# its

$m- mum mqu«Kfiy than any otter tisgl# brnneii ©f ©hemietryj Im fm%t tteit# m%»wgm®trib aaaaapaftgr «»€ .men often a pife*aqp£*it» to aapaftaim In «3l tfea otter 'rnmrnm ©f **•»«>

a*op#

fstry,

For this

*a»kijrtl*& ots®»ifibry m a t taka ni*»

taatage of every app*p£«&£tr to laarsaat it® soope aft* ttts t utilise a**«y $aaail&a a$$*«aalt ta * upioiflo

pamt&m*

fins «aa ©f «*&af4«atvt» ftatXwfta ms a »•**« ©f approaafe 3a. problem* AalUag * i* k the Aa*«v«*it*tloa o f elesieitt#, te n t* raAioala,. a*4 *M$«afeA* 1® a c t ww, hat tte -tapavta&a*'aaw given these netted# in *

Sa Sumy colorimetri© »»tti®§is fear# been

$f»p*ta* In ti» l*at ta» AaaaAaa Dal' t&a

XtUmtum

la aleggtA,

with them, and not until recently has tear* teen any attaapt t©

WtMAm

tfeaaa aatltoAa fr© « the p o in t af view ©f th e ir appli**

©ability in any but the most rig o r« « s iy jrt«atA«f*isnA taafetttea* The eritioal eratafttM at eolortiaetrle W itte *! Isas been pioneered by H* $* umilmt til) «aft M # Aevaffcosw.* ■ana at ib# present time* there «*» avallalDLa reliable la ta . aaaa«nil«ig a number ©f tbs amat widely m*#t oolorlmetrle aethoA** fllanont wait mm®g%so the photo* ##11.# sat oensogitontto tto tuto whloh they nontno&loA, so that &mt®aatl# toloaoing of toe ©irooit was obtain**#

fh# olllptloOl

»ipp#pg nontlonnA n m m ©«mstr«©t#t fro® atoning* sat w#r# to® otopo of portions of. to# «ftlip«oof owth having n w n m at tho oontor of to# galvanometer alrpor

foono

«n& to# other foono

at #®«h pfeotoooll* ■ fit® to® nftswero w m m |#1»#€ .half way tostotta the too ptotooolto*

fhm» shy toon of light two* to®

taiomonetor striking to# mirror# on# ooflootoft to ©litter on#

op too other of to® ptotoo«&.to* to® paper ownrlogo on to# *o*o»4»r woo flat its tfoowlog in wsy®. pooponAiooior to to® travel litf tor*

to it m m fattenet

o vernier whito •©?** ogolaot to# wore tongfh ©©ml® nonntoA on tot reoorter from®.

to# paper oorrioge wa« Join©! to to®

R eproduced with perm ission o f the copyright owner. F urther reproduction prohibited w itho ut perm ission.

» m ** «•*** of %®mm at p**«*

optioul systeo ©I the vtoualy dssorilnA*

St# traveling oarrlagO'Myittig the ■elegiposwtgiitt «&*o ita« w w tA e» i t

iw -ll» m m m m k m resistor* ant hm&

pmmi.®lm for holding *■ tomtomIft pon of tt» stylus variety* This ante s. tsoo&itg m the *otetei»g pops? of any m m m of I M s tevf&ng* sa& #«*«§#. tep&ot' tipeetay the va#i*tldft« in. ■the positlm of the teffisgs utth the » f t length getting*

B*

«jf tint

ffes sain flisten* gwlteti of the amplifier was tew*#* e». and the M o w pom&tte# to mmm. far five aimitos* of that time, the ttosotriog

A t the end

wm get at so*** «nA the

tettoote potentiometer fop the mmmwrnm : *i#e of the amplifier wm m adjusted with the eoarse ant fine resistors that the galvanometer deflection wm zero,

S i t wag observed by turn-

tag oo the galvanometer lump «t. opeiktag. the trap ten*

of the amplifier box Kftfctag the %%&& % » » visible*

ok

tap

Sis

fpegesi pot * « P # $*te*ti«& & m m m m the eoapeasating resistor.

S e n the i»ea«ip§.iig oooiotor *** set at 100 «tt the

$roess« repeated for ffee oilier half of the amplifier, thus pttftiag « sere potemflal top' onrooo the measuring restates?* Most, with the taste sotting of the Ktasortag resistor, the light in the KOKMlnPOMttep «te turned •lit opoteA to the desired vnl®«*

o k *.

&»#. S t exit

ftsea the ooKpeftMttag

R eproduced with perm ission o f the copyright owner. F urther reproduction prohibited w itho ut perm ission.

«

m

**

sw«t«*or m m ftdjmtod ratll ufalm a© d*fl*wti*a m

tfee $•&**»

»**•% *? v » i *to«*w*d» Bit® wttfc Hit grtwiiaiiwisr I m p Iwtitd off* the fN»«rier © irem it ww© darned on, and the g rid M a t on the g rid « « iiir® il© i iwwtttfUr* so rent*

tlmi lit© tulit* €li snot quit* jars wkp»

fill* netting m % M b i t tsr noting 'th* point at- wtiiiiii:

tli© wi*l*t glow in the trimm |««t &*•«*• *&•&!&•* « i then i w * lag %h@ M m

©©nirol until ills ft©*" dti«&>*M«ft*

ftieit lit#

ga&MMMtMMr l a m we# nfsAs tw&*d # % and tie elresili «*•

ready for *p***ll«*u t e n il» lamtlaft M>dtag th® ©asplet was a$«ft*d» the gul* f» # is l» ? «m tam ad o ff tn erisr %# prevent am? tig h t t m m t m r i a g « la rg e movement of th a t instrum ent.

0, Eesult® fp i# M a p X **!*! o f t ilt ln s tra « « t;» *& * f ir s t task was ©alih*mtl©« o# tn* wart length «*«&##

Shi* w » d m * M l a g *

-• M il is e lttit glow d lM & arg* fu ie j the l l f M

• « * * * • m s sw««v«d»

■and the huiltom trim s n h s tita te t in it s $1m *«

then the f l in k e r

w larw r sad It s h m s i » g w m » m m i * flats ekposiag the « i f s l i t e f the jMSft#*fev*Mt©&*

io ftt the tttiran ee m i the e x it

s lit s were ©peaei t * 0*d as*. « € M n d t o u o f the sp ##tr«i U m i .M i* r is a A lf *

v f *t» loeatlem s

Hat wm* le n ftii# were

-read d lr# # ily ..fro* tfe* w n ltag tX i « M l* wfclefe wm attaehed to the fjN »e # f the paper **« & *£ **

W5m apparent wars Xwagffec as

re a t from the instrum ent a#* *«ag»M«& to the tom* * * ! « * • to

R eproduced with perm ission o f the copyright owner. F urther reproduction prohibited w itho ut perm ission.

m*

*m-

table 1. fatt.® 1.

or w fra® value

m u uwfii ts«ji

Apparent value

Sever

667.8 « / i*

8 6 7 . 8 mju.

0 . 0 »yu.

itf.s

§®7,§

o ,»

4 0 5 *5

4 9 8 .3

0 .1

4 7 1 .3

4 7 0 .8

-0*5

4 4 7 .1

4 4 6 .3

-O .*

fbo soxt step i» the evaluation of the instrument was the AotoYKinatloit of the aaaeuat of stray light. esergiiig f r m ftoooofavoBator*

the

B trm light Is the light of w r * lengths other

than the®# desire#. It 1# dotova&aoA W Obtaining transmitto&flgr values at vaviouo umvo length# for Materials of which

the t*oiM«lttfi&oioo are feaooii* la this cast too glass filter* which hat boon- ««&&brat*4 by tbo lurecu of Stwistri*,, Ho#*, ever, wton an attoapt to use the opootvepbotoaetor for tfeto purpose wag aafio* it was fiaunt that the erratic behavior of tb* amplifier mat# the results of no value, sine* they were

not reproducible-. The two aoot noticeable difficulties were a raaios variation in the galvaaonotor deflection, which was aoitbe? oonatoat nor irreducible, tut# a slow bat stemAy drift,

which va* always in m e 4i*o*tl«n»

the amplifier was turned

on for a. period of time of twelve hours and at the end. of that

R eproduced with perm ission o f the copyright owner. Further reproduction prohibited w ith o u t perm ission.

«*

30

*»

time the drift was as pronounced as it .had been five s i w t « * after the initial weane-up period. slips

mf

Since the symmetrical d#»

the amplifier was intended to. eliminate the tendency

to drift, various parte in the amplifier including the tubes and batteries, 'were latttrtfifcttg«6*

*hie produced

wm

correction,

however.

In order to obtain the transmittaney values for the Stereatt of i t i M l M M fiiter%, it wmm finally w t m $ m a w *®

«ee of a

Weston Type 2 barrier layer cell, wl ich was placed in the posi*

lion of. the flickering' mirror, this being directly behind the exit slit of the monochromator,

this sell was connected dl»

reotly'to the galvanometer previously described, -and the

Wm

flections of the galvanometer wire read on a scale at a Aistsno# of three meters.

For each reading of traasmittanoy, the wave

length scale was adjusted, the slit* opened i® the desired value, and the initial reading: made with an cpaspie object in front of the entrance slit.

This gave the •dark* reading:,

which wm subtracted fro® -all subsequent resting#*

the opaque

object was then removed and the incident light value obtained as a galvsastteter deflection.

Since no constant voltage device

was available from which to operate the light source, an. «*«*« eg# of three readings was taken at each setting of the wave

length seal®.

Warn this average ■value wne obtained, the

filter

ist. a suitable holder was placed in front of the entrance slit, and again an average .reading was taken*,

the second of these

average value# was divided by the first and the rati# multiplied

R eproduced with perm ission o f the copyright owner. F urther reproduction prohibited w itho ut perm ission.

*** m ** fey 100*

this gave the p « o«n% t r m m t t t m m for

1» fable g are given the observe! and tame telnet for the treaaelttaiiegr of tee glaee flit®#® obtain.#! from the Buremi ©f gtaftdarda*

fufel® ?♦

crasm® ms suit faiiis ran

or m

m s

Fanis

Wmkiilii*a # of lilt fcitte-filter .1fe« 888*48. : red filter 11©, 0631 Wave length »##*¥#! ' ■ 'rite "ISK®eeii In m;u. .m r.m m t'. » r #s*rt ner eent ©er ©eat. ;

404*? 480.0 438.8 471.3 491.6 601.6 620.0 630.0 848.1 860.0 870.0 878*0 887.6 600.0 620.0 640.0 880,0 667.0 680,0 600.0

77.6 77.8 77.0 60*7 36.8 27.6 10,7 6.4 8,6 7.9

88*06 80.80 81.90 64,40 37.70 28.10 11.00 6.09 4.77 8.80

2.9 1,1 1.3 1.6 0.7 2.2 6.4 22.8 36.0

3.96 1*38 1*80 1.59 1.21 2.40 4.70 16,00 38.00

o.oc

0.00

0*00

0,00

*38 3*70 25.80 88*80 87*80 88.30 88*00

.03 0.45 17.20 69.00 ' 83.50 90.80 91,1C

88,00

91*88

tt##® volttoo when 'plotted in the ffeniller m ore length rareue tmaalttasiey fojne an #Mwa in Figure 10* they repw* e*nt & »@«i«§a rare length tend of 10 millimicrons? actually a aeseetiat larger tend end need atnee the exit edit was opened 'to

4 -wu while the entranee slit laetrwaeet was egeal to M B

mm

f as*

Iti# tlsptwl* «f the

ws* per aillittlereit, eo that the

R eproduced with perm ission o f the copyright owner. F urther reproduction prohibited w itho ut perm ission.

total silt wi#fch was aqaiffalaiit to'.o apaatoal twit of arl&th X4*S a&ll&alaroiis. .This is baoauaa ill® total slit witth is a 2. «6-