under the conditions of the present work, the effective radius of hydrogen ion is apparently affected more than that of potassium, as should be the case to agree with the results of the work cited above. Accordingly, values of D for 16% DVB smaller than those for 12% DVB resin indicate that both hydrogen and ammonium show an increased affinity relative to magnesium. This would be caused b y a larger relative decrease in effective ionic radius, due to stripping
the hydration Of the ion as compared with the divalent ion. Of
(4) Iirau>, I
Ion Exchanger Cellulose citrate CMC-30 Cellulose powder Phosphorylated cellulose CMS-cellulose Oxidized cellulose
-I,
47
45
114
112 48
50
220
200
220
220 200
220
commercial cation eschangers were used. These experiments showed that QAC cations \yere exchanged so strongly that they could not be removed by eluting acids such as hydrochloric, nitric, or sulfuric acid in n-ater, ethyl alcohol, or acetone. The interacting forces of the ion exchanger n-ith the QXC long carbon chain and with the highly basic ammonium group apparently n’ere too strong to be disrupted by an ordinary ion exchange technique. KOreports on this observation, hon-ever, could be found in the literature. Cellulosic materials have been described by several authors as neak cation exchangers (1-3). Several cellulosic ion exchangers were available in this laboratory and u ere investigated. Cellulose powder, cellulose citrate, carboxymethylcellulose, phosphorylated cellulose, oxidized cellulose, and partially carboxymethylated cellulose (CPI IS-cellulose) will exchange QAC cations from aqueous and nonaqueous solutions, either neutral or alkaline. The QAC was quantitatively recovered from the cellulose columns with alcoholic hydrochloric acid. The partially carboxymethylated cellulose (CIlScellulose) was the most effective ion exchanger. An analytical procedure was developed using the ChIS-cellulose colunin for removing and concentrating QXC from solvent estracts and other solutions. The extract or solution is passcd through the column, removed lyith alcoholic acid, and measured colorimetrically by a method similar to that of Wlson (8). EXPERIMENTAL
Apparatus and Reagents. SPECTRO-
Coleliiali Junior, Model 6A, Coleman Instiumrwts, Inc., Maywood, Ill.
~~~
PHOTOULTER,
PARTIALLY
C.4RBOXI METHYLATED
CELLULOSE, obtainable as Cellex C b i from the Brown Co., Berlin, K. H. It m a y also be made a s described b y Peterson and Sober (7)) rrho called i t CLIX-cellulose. Ioix EXCI~AXGE C o ~ u a ~ macle s, by packing a 2.5 X 40 cni. glass column to a height of 8 em. IT it li CMS-cellulose, washing 11 ith 5 nil. of 1-1- hydrochloric ncid, aiid then n ashiug with distilled TI ater until the n ashings are neutral. 1-Y‘ILCOHOLIC HIDROCHLORIC ACID, nxide by adding Sr5nil of concentrated h\tlrochloiic acid t o 1 liter of formula 3-4 e t h j 1 alcohol. I ~ D I C A T0.1% O R , brornoplieriol blue in formula 3A ethyl alcohol. Analytical Procedure. SAMPLE PREPARATIOS. Solutions containing Q=lC niay he placed directly on t h e r.olunin. Solid samples containing QAC, such a s nnimnl feeds, must first bp extracted TI itli chloroform, using a continuous extractor. ;1 1hour extraction period is usually sufficient. IJSE OF CLIS-CCLLLLOBC COLUMK, -111 aliquot containing 0.1 to 0.5 mg. of Q-AC is added to the CLIS-cellulose column. The column is then washed u i t h 25 ml. of ethyl rilcohol, followed by 25 ml. of distilled nater. These n ashings arc discarded. From this point on in the procedure, extreme care m i s t be taken to clean soap and anionic detergents from glassn are, because these materials n ill react n ith QAC to give low results. -4 test tube or small beaker is placed under the column aiid 5 nil. of 114’ alcoholic hydrochloric acid are added to the column. The column is then nashed with 30 nil. of distilled water. Color Development. T h e alcoholic acid a n d aqueous washings are collected a n d placed in a 250-ml. separatory funnel. Fifty milliliters of chloroform are pipetted into t h e funnel, followed b y 1 ml. of bromophenolblue indicator. T h e funnel is shaken for 1 minute a n d the layers a r e allowed t o separate. T h e Ion-er chloroform layer is transferred t o a second separatory funnel which contains 10 nil. of 1% sodium carbonate solution. This funnel is shaken for 15 seconds and the layers are allowed to separate. If QAC is present, the Ion-er chloroform layer nil1 be blue. The layer is transferred to a glass-stoppered flask containing 0.5 gram of anhydrous granulated sodium sulfate and alloned to stand for 30 minutes. Finally, the absorbance of the solution is read a t 603 mp using chloroform as a blank. The concentration is determined by reference to a previously prepared absorbance 25s. concentration curve niade from known amounts of QAC. The method is readily scaled down b y using smaller amounts of chloroform. For 50 t o 100 y of QAC, 25 ml. of chloroform are sufficient; for 10- to 50-7 amounts, 10 ml. of chloroform are enough.
Table II. Recovery of Trimethyloctadecylammonium Stearate from a CMSCellulose Column
Added, 10
Found,
-j
yo
8 . 4 dz 1
1 8 . 7 S= 3
20
60 100
57.6 f 5 96.6 f 5
200 400
199
i4
404 i 5 a Average of 4 determinations. Table 111. Determination of Trimethyloctadecylammonium Stearate in Various Samples Using CMS-Cellulose Columns
QAC Added, Sample Ground corn Grouiid corn -4lfalfa 307; corn Alfalfa 45% corn
+ +
Commercial lion feed Corn feed Dried dog food
QAC in -kliquot, Y P.P.M. Bdded Found 55 132 134 220 242 244 110
114
120
220
134
134
110
115
115
Y
ANli
0 1200
0 0 0.0 240 230 100 06 447 413
4
Eggs (liquid)
45
Table V. Use of Cellulose Columns to Exchange the Anion of Quaternary Ammonium Compounds Ke-
Starting Eluting QAC Acid Anion Usedn 1Oyoacetic Chloride Chloride 10% citric Chloride 1X sulfuric Chloride 114’ nitric Stearate 1X hydrochloric Laurate 1B hydrochloric Palmitate lhl hydrochloric Pelargonate 1N hydrochloric Citrate 1N hydrochloric In ethyl alcohol.
covered &.IC .hion
.tee t :t t e Citrate Sulfat e
Zit r:i te
Chloride Ch!oride Chloride Chloride Chloride
0
Table VI. Determination of Trimethyloctadecylammonium Chloride in Dilute Aqueous Solutions Using a CMSCellulose Column
QAC Added *//500 P.p.m. ml. 50 100
0.1
200
0.4
300 400 500
0.G 0.8
0.2 1 .o
QAC Found, P.P.1I.a 0.11 i: 0.01 0.10 S= 0.01 0.40 S= 0 . 0 1
0 59 f 0.02 0.79 f 0.02 0.99 i- 0 01
Average of 3 determinations. Table IV. Determination of Various Quaternary Ammonium Compounds Using a CMS-Cellulose Column
Compounds Trimethyloctadecylammonium pelargonate Trimethyloctadecylammonium laurate Trimet hyloct adecylammonium citrate I rimetliyloctadecylammonium palmitate Trimet hj-lhesadecylammonium laurate Trimet hyl-“coco’ ’ammonium tartrate 7 1 ,
Added,
Found,
Y
Y
1so
177
425
420
400
500
200
190
320
324
205
200
Regeneration of Column. The column can be regenerated b y washing with distilled water until t h e washings are no longer acidic a n d by then washing with 10 ml. of ethyl alcohol. One column niay t h u s be used repeatedly. DISCUSSION
The cellulosic exchangers tried and some recovery values for QAC are listed in Table I. CRIS-cellulose swelled the least, retained its exchange capacity the longest, and was insoluble in both aqueous acid and aqueous base. It was finally settled upon for subsequent work. Detailed study showed that cellulose po\vder had too small a capacity because it had relatively few carboxyl groups.
The carboxymethylcellulose m-as partly soluble in water and sv-elled to plug the columns; the cellulose citrate and phosphorylated cellulose, being esters, hydrolyzed after a time to lose their acid groups and, thus, their capacity. Table I1 shon s the quantitative recovery of QAC from CLIS-cellulose a t several levels of concentration. The stearate \?-as deliberately chosen for analysis because of the difficulty n i t h which i t has been determined by methods other than those of column eschange. Greater sensitivity TI-ould be expected with a halide in n-hich the cation Lvould represent a larger proportion of the molecule. I n the extremely low ranges (10 y of stearate or less), the loss of QAC due to surface effects causes a relatively large error. A number of typical samples, mostly animal feeds, were made by adding knon n amounts of trimethyloctadecylammonium stearate. These samples were then extracted ith chloroform and the extract was analyzed by the procedure described (Table 111). The application of the cellulosic column technique to QAC nhich have various other cations and anions is shown in Table IT‘. This indicates a n-ide range of QAC to which the technique can be applied. T o show whether the QAC mere simply being molecularly adsorbed or whether ion exchange was taking place, several QAC n ith different anions were VOL. 32, NO. 1, JANUARY 1960
71
placed on columns. They were then removed with different acids and recovered from solution. The results of these experiments are shown in Table Y. I n each case, the recovered anion n a s found to be that of the eluting acid, not that of the original QAC salt. Table VI demonstrates the use of the ChIS-cellulose column for concentrating water-soluble QAC from very dilute solutions. Known weights of triniethyloctadecylammonium chloride were added to 500 ml. of distilled water to bring the concentration to 0.1 to 1.0 p.p.m. The entire 500 ml. n-ere passed over the column and the concentrated QAC was determined as described. The recoveries on the average were slightly low. The weight loss, however, appeared to be fairly constant, suggesting
that it was due to the surface activity of the quaternary salt. The ease with which the QAC anions are exchanged on cellulosic columns suggests that the method could be used to Obtain Or prepared &hC. The eluting acids are all relatively strong acids. They must also be soluble in ethyl alcohol or some similar solvent, because aqueous acids produce practically no recover)' from the columns. The choice of anions is therefore limited, but the technique is nevertheless useful.
( 2 ) Elvidge, L). A., Proctor, K. A.7 Baines, C. B., Analyst 82, 367-72 (1957). (3) F ~ F, hf,, ~ J , pham, ~ and ~ Pharmacol. 8, 42-5 (1956). (4) Furlong, T. E., Elliker, p. R.,J. Dairy Sci. 36, 225 (1953). ( 5 ) Harris, T. H., J . A4ssoc, Ofic. Agr. Chemists 29, 310-11 (1946). (6) Miller, D. D., Elliker, P. R., J . Dairy Sei. 34, 279-86 (1951). ,;:# 7 ~ ~ ~ ~J . ~ (8) \\-&on, J. B., J . Assoc. Ofic. Agr. Chemists 29, 311-27 11946). (9) Ibid., 31, 480-4 (1948). (10) Ibid., 33, 666-70 (1950). (11) Ibid., pp. 670-4. (12) Ibid., 37, 374-9 (1954).
(TiFg:OI'j &;
LITERATURE CITED
(1) Calman, C., Kressman, T. R. E.,
"Ion Exchangers in Organic and Biochemistry," p. 555, Interscience, Sew Pork, 1957.
RECEIVED for review July 8, 1959. Accepted October 19, 1959. Division of iinalytical Chemistry, 135th Meeting, ACS, Boston, Mass., April 1959.
Standard Titanium-Hydrogen Samples M. J. TRZECIAK' Battelle Memorial Institute, 505 King Ave., Columbus 7, Ohio
b A method is described for making individual titanium-hydrogen standards to b e used in comparing results of analysis by a given laboratory with the amount of hydrogen added to the standard samples. A total of 67 standard samples were analyzed separately by five laboratories. There was agreement between the result of a given laboratory and the amount of hydrogen added to within 3% on 41 samples and to within 6% on 19 samples. Agreement on seven samples was outside these limits.
I
Diffusion pump
dm; r
s view of the growing recognition of
the importance of gas concentrations in metals, there is a need for standard samples to standardize and evaluate techniques for the analysis of gases in metals. A program is described &-hose objective was the preparation of standard tiThe tanium-hydrogen samples (6). preparation technique was checked by analysis in the Battelle Laboratory, and standards were then supplied to other labora4ories to use as guides in appraising the performance of recently constructed analytical apparatus. A frequent difficulty in many roundrobin programs is that samples are taken from heterogeneous materials and submitted to various laboratories. Also, the presumed standard samples are not 1 Present address, Glendale Laboratory, International Business Machines, Inc., Endicott, N. Y.
72
ANALYTICAL CHEMISTRY
furmce
Open-end,
Fore-Pump
11 Exhouri
Figure 1 .
Apparatus for preparing titanium-hydrogen standards
truly standards but rather samples of unknown gas content. The concentration levels of these samples are determined by the analytical methods whose reliability they seek to establish. It is that the method presented here for standard sample preparation overcomes these difficulties.
technique a t 1300" C. (4). The rods retained from
