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Im p in g er Studies o f V o la tility o f FC -95 and FC -143
Intoduction and Purpose:
Thermospray mass spectrometry was used to quantitate a number of samples for FC-143 and FC-95. The overall purpose o f this experiment is to determine whether or not FC-95 and/or FC-143 has an appreciable vapor pressure at room temperature. This experiment consists of two parts. The first part of this experiment is to test whether either of these compounds are removed from a variety of solutions when air is bubbled through them. In the second part of this experiment, a solution of ammonium acetate in 1-propanol:water is used to trap any FC-95 and/or FC-143 that volatilizes at room temperature.
Parti
The solutions that were tested to see if either or both of the fluorochemicals are removed from them upon passing air through them are described below:
Label
1 2 3 4
5
6 7 8
9 100A 200A 400A 800A 2000A
Compound
Tetrabutylammonium hydroxide Ammonium acetate Laurylpyridinium chloride n-Alkyldimethylbenzylammonium chloride Cetyltrimethylammonium bromide TaUowtrimethylammonium chloride Dicocodimethylammonium chloride Water/1-propanol (50:50) Water/1-propanol (50:50) Amonium acetate in water/1-propanol (50:50) Amonium acetate in water/1-propanol (50:50) Amonium acetate in water/1-propanol (50:50) Amonium acetate in water/1-propanol (50:50) Amonium acetate in water/1-propanol (50:50)
C oncen tratio n
500 ppm 500 503 500 500 505 500
0 0 500 500 500 500 500
[FC9S]
10.0 ppm 10.0 10.0 10.0 10.0 10.0 10.0 10.0 0.00 0.10 0.20
0 .4 0
0.80 2.00
[FC143]
10.0 ppm 10.0 10.0 10.0 10.0 10.0 10.0 10.0 0.00 0.10 0.20
0 .4 0
0.80 2.00
Parti!
A 50:50 water/1-isopropanol solution containing 500 ppm ammonium acetate was used in the second part o f this experiment. In this part o f the experiment, FC-95 or FC-143 is placed in an apperatus which air is passed through. Glass wool is placed downwind of the fluorochemicals to trap any particulates. After the air passes over the fluorochemicals and through the glass wool, it is bubbled through a train of imping ers containing the ammonium acetate solution. If the first part of the experiment shows that there is no loss of fluorochemicals upon passing air through the solutions, it is expected that if there is any fluorochemicals present in the air, they will be transferred to and retained by the ammonium acetate solution.
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E xperim ental
An Extrel ELQ-400 was used with a Vestec thermospray to quanitate these samples. FC-95 is quantified by monitoring the ion current at m/z 499, FC-143 is quantified by monitoring the ion current at m/z 413. A Waters 600-MS HPLC pump with SILK was used with a Waters WISP 712 autoinjector for delivering 10 uL injections of the sample to the thermospray. The mobile phase composition was 39:60:1 acetonitrile:w aterl ppm tetrabutylammonium chloride flowed at 1.5 ml/min. The tip temp pot was set to 4.75 while the block pot was set to 5.3.
For each sample, three injections were made for both the stock solutions, which were spiked with the fluorochemicals but did not have air blown through them, and the "blow" solutions, which are identical to the stock solutions except that they had 280 liters of air passed through them. Thus, the stock solutions serve as controls for measuring loss of fluorochemicals. The stock and blow solution injections were staggered to minimize the effects of any drift in the mass spec response. The integrated areas o f the selected ion currents for the blow and stock solutions are averaged, adjusted for volume changes caused by passing the air through the impinger, and then ratioed. This adjusted ratio then reflects the amount of fluorochemical that remained in solution after passing the air through the impinger. A ratio of 1.00 indicates no loss of fluorochemicals, while a ratio of 0.00 would indicate a total loss of the fluorochemicals upon passing air through the solution.
Results
Parti
The results of Part I of this experiment are summarized below. These results indicate that there is some loss of fluorochemicals upon passing air through most of the solutions, but most of the solutions retained 85% or more of both fluorochemicals. This suggests that both FC95 and FC143 are capable of volatilizing out of most of these solutions.
S o lu tio n Tetrabutylammonium hydoxide. Ammonium acetate Laurylpyridinium chloride n-Alkyldimethylbenzylammonium chloride Cetyltrimethylammonium chloride Tallowtrimethylammonium chloride Dicocodimethylammonium chloride W ater/l-Propanol (50:50) Ammonium acetate in water/1-propanol (50:50) 100 ppb Ammonium acetate in water/l-propanol (50:50) 200 ppb Ammonium acetate in water/l-propanol (50:50) 400 ppb Ammonium acetate in water/l-propanol (50:50) 800 ppb Ammonium acetate in water/l-propanol (50:50) 2000 ppb
% Retained FC143 83 90 90 101 95 90 89 85 98 108 85 89 92
% Retained - FC95 90 71 90 100 95 93 84 89 96 101 90 95 96
P a r tii
No fluorochemicals were found to be present in either the first or second impinger. This indicates that the amounts o f FC95 and FC143 transported from the solids to air and then into the solution is below the sensitivity of the instrument, thus suggesting that both compounds are involatile or have very low vapor pressures as solids.
No fluorochcmlcal were found lo b e ptcacatia cither the firn or second impiagcr. This indicates that the amounts o f PC95 sad PC143 transported from the solids to sir and then into the sotatrioo b below the sensitivity o f the method, tbcs suggesting that both compounds sre tavolatile or have very low vapor pressures ss solids at room temperature. Estimates o f the maximum vspor pressore o f these compounds are presented below.
C on clu sion s
Almost all of the solutions tested in the first part of the experiment retained over 80% of both fluorochemicals, with an average retention of 92 % for both FC95 and FC143. This indicates that there is loss of the fluorochemicals from most of the solutions, but some of the solutions, particularly the n-aOcyldimethylbenzylammonium chloride solution, appears to retain all of the fluorochemicals.
A solution of 500 ppm ammonium acetate in a 50:50 mixture of water 1-propanol was used in the second part of this experiment The solutions of ammonium acetate in water 1-propanol had an average percent retention of 94% for FC95 and 93% for FC143.
Neither PFO nor PFOS was found in any of the impingers that were tested in the second part of this experiment The sensitivity of the method is such that the flouorocbemicals should be detected in the impingers if ibe vapor pressure of the given compound exceeds approximately l-lO-7 tore. Since neither compound was observed, the vapor pressure of both of these compounds is less than 1 -107 tore.
This experiment does not address issues related to kinetics of phase transfer, which may be important
Maximum Vapor Pressure Calculations Minimum concentration required >oquantify Bring thermnspray mass sp ec: 25 ppb
Minimnm amount of Quorochemical transferred to impinger needed to q-- u tty :
(.0 2 5 ug / m /)(25 ml) = 0 .6 2 5 u g /m l
Eq. 1
Assuming that 90% o f the fluorochemicals that are transferred to the air w ill be trapped by the first impinger, the minimum mnnt n f nnnmrtiwifi th a t n m k tn be present in the 280 b ia s o f air that is
passed over the fluorochemical and through the impinger train:
(0 .6 2 5 ug/ m l) /0 .9 = 0 .7 ug
Eq. 2
Converting this to moles of FC95 and FC143 gas molecules:
FC95
0 - 7 ' 1<r* 8 = L 3 -1 0 -9 mol 538 g / mol
FC143 0 7 10^ = 1 .6 -IQ-9
431 g ! mol
Eq. 3 Eq. 4
Assuming the air behaves as a mixture of ideal gases and the air is at standard pressure, the number of moles of air molecules in 280 liters of air at 20 *C is:
2 8 0 liters 2 73 K
= 11.4 mol
(2 2 .4 1 4 liters / mol) 293 K
Eq. 5
The following equation then gives the minimum vapor pressure the flooroJ u juici l salts must have to be measured by this experiment:
FC95
-1--.3----*--1--0-----m--o--l- 7n 6. .0. torr = 8n. m7 - 1*0a4 tjon11.4 mol
Eq. 6
FC143
L 6 10-9 mol 7 6 0 torr - L I 10'7 torr 1 L 4 mol
Eq. 7
Since no fluorochemicals were found in any of the impingers that were tested, the vapor pressures of these two compounds is less than the minimum values shown in equations 6 and 7.
1-aoc* 3503 1-Aaratod 4074
Mtock 4184 2-Aated 4026
3-Stock 2576 3-Aaratod 2614
Stock 3890 4-Aeratod 4243
5Stock 2443 5-Aarated 2516
6-Stock 5779 6-Aerated 6219
7-Stock 5436 7-Aerated 5778
8-Stock 6155 8-Aerated 6583
9Stoek 9-Aerated
0 0
100A 1008
134 140
200A 2008
175 209
400A 4008
317 391
800A 800B
563 615
2000A 20008
1303 1389
3968 4444
4361 3388
2596 2699
4120 4426
2454 2542
5778 6589
6031 5964
6338 7342
0 0
93 109
185 210
316 382
568 633
1286 1331
4421 4254
3254 3590
2583 2785
4250 4595
2427 2502
6060 6635
6175 5156
5539 5246
0 0
99 108
168 206
363 353
471 411
815 981
3964 4257
3933 oooo
2586 2699
4067 4421
2441 2520
5879 6481
5881 5633
6011 6390
109 119
183 209
332 375
534 553
1135 1234
107 93 104 108 103 110 96 106
96 101 90 95 96
90
71
90
100
95
93
84
89
/WOA 96 168 160 306 276 491 468 1044 999
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P art I D ata
PFO
Sam ple 1-Stock 1-Blow
2-Stock 2-Blow
1st In ject 2963 2989
2nd In ject 3157 3407
3rd Inject 3434 3067
A verage
3185 3154
%Blow/Stock Adjusted % 99 83
3334 3702
3247 2533
2093 2621
2891 2952
102
90
3-Stock 3-Blow
4-Stock 4-B lo w
5-Stock 5-Blow
6-Stock 6-Blow
7-Stock 7-Blow
8-Stock 8-Blow
9-Stock 9-Blow
100 A 100B
200 A 200 B
400 A 400 B
3033 3207
3197 3471
4751 " 5522
5466 5854
3884 4273
4612 4342
4052 4361
4107 4371
3811 3838
3625 3768
5076 5220
5181 5390
0 0. 00
105 81 125 89
136 164 181 163
295 274 316 326
3674 3631
5877 6294
4444 4798
4207 4540
3586 3500
5105 5008
0 0
88 90
129 181
311 292
3301 3436
5365 5890
4313 4471
4122 4424
3674 3702
5121 5206
91 101
143 175
293 311
104 90 . n o 101 104 95 107 9 0 101 89 102 85
% B/A 98 108 85
% /1 0 0 A
98
157 169
321 273
800 A 800 B
2000 A 2000 B
515 530
1201 1226
532 537
1196 1182
365 301
590 712
471 456
996 1040
89 92
515 459
1090 1002
P art II D ata
PFO
Sam ple T ill T 1 I2
T 2 I1 T 2 I2
T 2 I1 T 2 I2
1st In ject 0 0-
2nd In ject 0 0
3rd Inject 0 0
A v e ra g e 0 0
00 00 00 00
00 00 00 00
PFOS
Sam ple
T ill
T 1 I2
1st In ject 0 0
2nd In ject 0 0
3rd Inject 0 0
A verage 0 0
T 2 I1
0
0
00
T 2 I2
0
0
0
0
T 3 I1
0
0
0
0
T 3 I2
0
0
0
0
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NUMBER
COUPOUNDHAUE
CONCENTRATION H ITIA L VOLUUE FH A L VO U IU E START T H E tw w
1 Tetrabutyl ammonium hydroide
500 ppm
25
21 11:35
2 Ammonium acetate
3 Lauryi pyridinium chloride
500 ppm 503 ppm
25 25
22 11:35 21.5 11:35
4 n-Alkyldim ethybenzylam m onium chloride
500 ppm
25
23 11:35
5 Cetyhrimethyiammonium chloride
500 ppm
25
23 11:35
6 Tallow trimethytammonium chloride
505 ppm
25
21 9:35
7 Dicoco dimethyl ammonium chloride 8 H20/1-propanol (50:50) FC 95/143 9 H 20/1-propanol 1 0 .25 ml 11 .5 ml
12 1 ml 13 2 ml 14 5 ml
500 ppm 10 ppm
??? 100 ppb 200 ppb 400 ppb 800 ppb 2 ppm
25 25 25 25 25 25 25 25
22 9:35 21 9:35 22 9:35 22 8:52 22 8:52 20 8:52 23 8:52 22 8:52
15
16
EN O TH E
S A tP l P 0 *O O FLO W R ATE TOTAL AMT VOUJUE
In M M )
N nM O
16:16 16:16 16:16 16:16 16:16 Auto Auto Auto Auto Auto Auto Auto Auto Auto
280 280 280 280 280 280 280 280 280 280 280 280 280 280
1 1 1 1 1 1 1 1 1 1 1 1 1 1
280 280 280 280 280 280 280 280 280 280 280 280 280 280
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SAUPLE O eSR PTIO N
UM NQ ER SOLUTION
M T W . VOLUME P M U . VOLUME START TU IE EN O TR IE SAU PlEPER tO O FLOW RATE TOTAL A H VOLUME
fir * )
fir * )
firtn u tm )
fitm fir * )
Train 1 / Im pingar 1 Hao / 1-Propanol 500 ppm Ammonium A caule Train 1 / Im pinger 2 H20 / 1-Propano< Train 2 / Im pinger 1 H20 / 1-Propanol 500 ppm Ammonium AcaUle Train 2 / Im pinger 2 H 20/1-Propanol 500 ppm Ammonium Acetate Train 3 / Im pinger 1 H20 / 1-Propanol 500 ppm Ammonium AcaUle Train 3 /Im p in g e r 2 H 20/1-Propanol 500 ppm Ammonium Acatale
!
1
25 25 25 25 25 25
10:45 10:45 10:45 10:45 10:45 10:45
Auto Auto Auto Auto Auto Auto
280 280 280 280
See Comment See Comment
1 1 1 1 1 1
280 280 280 280
See Comment See Comment
COMMENTS: Pump on Train 3 failed at 181 minutes. There was a 25 minute span of time when no sample was being pumped. The total sample time was 255 minutes.
Mi DUO : [ 3 0 1 , 1 J D 4 7 2 1 , , 0 7 - O C T - 9 3 , 0 5 : 0 6 : 5 1
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DUO : [ 3 0 1 , 1 J D 4 7 2 2 . , 0 7 - O C T - 9 3 , 0 8 : 4 1 : 1 9
DUO : [ 3 0 1 , 1 ] D 4 7 2 2 , , 0 7 - O C T - 9 3 , 0 8 : 4 1 : 1 9 S i Ms s : 4 1 2 . 6 - 4 1 3 . 5 , S n s : 1 -1 0 0 3 2 , M a x : 9 7 9 , C Ma x : 9 7 9 , R T : 0 . 0 , 2 0 4 . 0
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DUO : [ 3 0 1 , 1 ] D 4 7 2 3 , , 0 7 - O C T - 9 3 , 1 2 : 0 7 : 5 8 S1 M s s : 4 9 8 . 6 - 4 9 9 . 5 , S n s : 1 - 1 0 0 3 3 , M a x : 7 2 2 , C Ma x : 7 2 2 , R T : 0 . 0 , 2 0 4 . 0
1 000
T T'T 2000
T-- --T 3000
T 4000
isp T
5000
DUO : [ 3 0 1 , 1 ] D 4 7 2 3 , , 0 7 - O C T - 9 3 , 1 2 : 0 7 : 5 8
S1 M s s : 4 1 2 . 6 - 4 1 3 . 5 , S n s : 1 - 1 0 0 3 3 , M a x : 3 7 8 ,
6000 C Max:
V '1 | 1 T ' I I'
7000
8000
378, RT: 0.0,
9000 204.0
7 T-r f p*
1000
,''..8^,-top;
2000
3000
4000
T r~ 5000
..y . i i -- , i r - --
6000
7000
8000
9000
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DUO : [ 3 0 1 , 1 ] D 4 7 2 4 , , 0 7 - O C T - 9 3 , 1 5 : 3 3 : 2 1 S1 M s s : 4 9 8 . 6 - 4 9 9 . 5 , S n s : 1 - 1 0 0 3 3 , M a x : 1 0 . C M a x : 1 0 . R T : 0 . 0 , 2 0 4 . 0
S1 Mss : 4 1 2 . 6 - 4 1 3 . 5 , S n s : 1 - 1 0 0 3 3 , M a x : 7 , C M a x : 7 , RT : 0 . 0 , 2 0 4 . 0
1000
"1 I 1 2000
3000
4000
' I' 5000
6000
^I' 7000
8000
1 I^ 9000
DUO : [ 3 0 1 , 1 J D 4 7 2 5 , , 0 7 - O C T - 9 3 , 2 0 : 5 5 : 5 0
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DUO : [ 3 0 1 , 1 ] D 4 7 2 5 , , 0 7 - O C T - 9 3 , 2 0 : 5 5 : 5 0 Q 1 Mss: 4 1 2 . 6 - 4 1 3 . 5 , S n s : 1 - 6 4 8 5 , Max: 1 9 9 , C Max : 199, R T : 0 . 0 , 0 . 0
' 1-- 1000
--i--|--i--r--i--j--r"
2000
''' I ' ' 3000
r " i 1 i ...... | i " 11-- r --T
4000
T - t - -j | | 1 |....1
5000
I I I | I 1" 6000
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DUO : [ 3 0 1 , 1 ] D 4 7 2 6 . . 0 8 - O C T - 9 3 , 1 1 : 3 1 : 1 3 S1 M s s : 4 9 8 . 6 - 4 9 9 . 5 . S n s : 1 - 5 7 9 5 , M a x : 1 0 0 5 , C Ma x : 1 0 0 5 , R T : 0 . 0 , 1 1 7 . 8
-T-- |"--V* , , , 1000 DUO : [ 3 0 1 , 1 ] D 4 7 2 6 , ,
r - i- i - i | i i-- 1 - i 1r 11 i i i | t i
2000
3000
08-OCT-93, 11:31:13
i
I I" !'" I I 1^ T' I
*I
4000
5000
II
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Vapor Pressure M easurem ents o f FC 95 and FC 143 E xperim ent #3
Introduction
This is a continuation of a series of experiments designed to obtain measurements of the vapor pressures of FC95 and FC143. This is the third experiment in this series. A second experiment was run prior to this experiment, but a solution was accidently used in the impingers that had been spiked with 10 ppm FC95 and 10 ppm FC143. The intent of this experiment is to measure the vapor pressure of these two compounds at 90 C. The apperatus use in this experiment was described in a report entitled Impinger Studies o f Jthe Volatility of FC95 and FC143. which is filed in the LIRN system under L3306.
Results and Discussion
During this experiment, a l-propanol:water (50:50) solution containing 500 ppm ammonium acetate was used in the impingers to catch any volatilized fluorochemicals. This solution was used to be consistant with the first experiment for measuring the vapor pressures o f FC95 and FC143 at room temperature.
FC143 was found in all three impingers o f both trains, indicating that FC143 has a measureable vapor pressure at 90 C. It also indicates that the solution used in the impinger trains is not efficient at catching fluorochemicals in the air that passes through them at the flow rates that were used in this experiment.
The vapor pressure of FC95 at 90 C measured much lower than the vapor pressure of FC143 in this experiment, but it does appear that FC95 has a measureable vapor pressure at this temperature. The amount of FC95 measured in the first impinger o f both trains was higher than any of the reagant or impinger blanks. The values measured for the amounts of FC95 in the blank impingers were subtracted from the values measured for the amounts of FC95 in the impingers after the warm air had been bubbled through them before the vapor pressure calculations were performed.
The raw data and integrated data are shown in the following pages. The results of this experiment are given below. These results are minimum vapor pressures for the two compounds at 90 C, since it appears that the impinger trains did not catch all of the fluorochemicals that had been volatilized.
FC95 FC143
1.2-10-7 torr 1.1 *10'5 torr
0~
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V apor P ressure C alculations
Total amount of fluorochemicals found in the impinger trains : FC95
Impinger train #1
(0.0 5 -1 5 + 0 .0 2 -1 8 + 0 .0 1 -7 ) = 1.2 ug C., 75'0-'}
Impinger train #2
(0 .0 2 9 + 0.02 16 + 0 .0 0 8) = 0.5 ug
Eq. 1A Eq. IB
FC143 Impinger train #1
(1.43 1 5 + 0 .9 2 -1 8 + 2 .3 4 -7 ) = 5 4 .4 ug
Average = 0.8 ug
Eq. 2A
Impinger train #2
(0 .9 5 -9 + 2 .0 0 -1 6 + 1 .9 1 -8 )= 55.8 ug
Eq. 2B
Average = 55.1 ug
Using the average values measured for the number of grams of FC95 and FC143 The number of moles of
FC95 and FC 143:
FC95
0 .8 - IQ-6 g 538 g / mol
1.5- IO'9 mol
Eq. 3
FC143
55.1-lQ-6 g = 1 .3 -IO'7 mol
431 g ! mol
Eq. 4
Assuming the air behaves as a mixture of ideal gases and the air is at standard pressure, the number of moles o f air molecules in 280 liters of air at 20 *C is:
280 liters 273 K
= 9.39 mol
(22.414 liters / mol) 363 K
Eq. 5
The following equation then gives the minimum vapor pressure the fluorochemical salts must have to be measured by this experiment:
FC95
1.5-IQ-9 mol 760 torr
9.39 mol
1.2 -10*7 torr
Eq. 6
FC143
1.3-101 mol 760 torr
9.39 mol
1.1-10'5 torr
Eq. 7
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Sw.l
December 7 , 1993
D r. Jim Wolter 3M Environmental
Dear Dr. Wolter:
With respect to our telephone conversation on 12-6-93 concerning your document "Impinger Studies o f Volatility o f FC95 and FC143" faxed to me on 1 2 -3 -9 3 ,1 am sending the following com m ents.
Part I: Volatilization o f fluorochemicals from some aqueous solutions With the vapor pressures which FC95 and FC143 are likely to have, it is difficult to believe
that these salts would be removed by air passing through aqueous solutions except by two mechanisms. The first is entrainment where micro-droplets o f water could carry material out o f solution. A second mechanism would be appropriate in cases where the fluorochem ical is dissolved in an aqueous solution containing surfactant. At surfactant concentrations near or even below the CMC (critical m icelle concentration) the passage o f air through the solution should lead to an appreciable production o f foam bubbles. A number o f processes involve foam fractionation to remove dissolved materials from solution and I believe that it is certainly possible in the present case with surfactant solutions (e .g ., 500 ppm o f CTAB, cetyltrim ethylammonium bromide) to extract FC95 and/or FC143 under the conditions o f these experiments.
Part II: Gas saturation attempt to measure vapor pressures o f solid FC95 and FC143 Based on a minimum detection level, the vapor pressure calculations seem appropriate
(except for a trivial question about molecular weights: FC143 seems to have an ammonium counterion and FC95 seems to have a potassium counterion?). The calculated vapor pressures are semi-plausible but I don't think that the experimental conditions provide firm evidence that the numbers are reasonable. A crucial point in the gas saturation method is the attainment o f vapor equilibrium with the flowing gas. W ith no detectable signal, one does not have a handle on this question. In the general sense, it would be highly desirable to have a reference substance with known vapor pressure done in a similar experiment. From die brief literature reading which I have done, it appears that the gas saturation method is not recommended for determination o f vapor pressures below a few millitorr. Knudsen effusion might be employed in the case o f very low vapor pressures. Since these fluorochemicals are very stable, a possible alternative procedure would be to repeat the gas saturation experiment at substantially higher temperatures such as 100 to 150 deg. C , for example. Finding measurable signals in such a range should enable extrapolation to a room temperature vapor pressure.
Sincerely yours,
Edwin E. Tucker, Ph. D . Chemistry Department-University o f Oklahoma Norman, OK 73019 T d . (405) 325-2054; Fax (405) 325-6111
Ub/lb/2000
t N V i K U N Mt N IAL LAfc5UKAIUHY
ARCHIVED FINAL REPORT
R A O K T O MAIM
B A C K T M A 'N
LAB REQUEST NO. L3306 REQUESTOR NAME: JDJ DEPARTMENT: 0222 PROJECT NO: 06 DATE RECEIVED: 12/13/1993 DESC: VOLATILITY OF FC95 AND FC143
CONTRACT LAB(S): EXP COMP DATE: 12/17/1993 DATE COMPLETED: 12/15/1993 PROJECT LEAD: PHONE NO: 3M FAX NO: 651-778-6176
Inpinger study I.
SAMPLE DATE
CODE
DESCRIPTION RESULT
MDL or (95% C.I.)
1 JTW-SPEC
SPECIAL STUDY - JTW
COMPLETE
