commercial DEB’S are shown in Table I. No attempt was made to identify the materials that emerged just before and after the D E B peaks. CONCLUSIONS
Because this column gare good resolution of the D E B isomers it was
possible to correlate the stability of commercial DEB’S toward attack by nitric acid with their compositions. The stability of TBP-DEB mixtures, as measured by fission product extraction, increased with increased meta and decreased para concentrations and verified the results of tests with the pure isomers.
LITERATURE CITED
( I ‘ lfortimer, J. V., Gent, P. L., S a t w e 197, 789-90 (1963). ( z ~ $ ~ ~ $ ~ ; . S a m u e lF., *‘saL. 35,
CHARLES 4.B L ~ K EJR. ,
Oak Ridge xational LaboratorS-l
Oak Ridge, Tenn. I Operated by ~~i~~ Carbide carp. for the U.S. Atoniic Energy Commission.
Spectrophotometric Determination of Fatty Amines in Aqueous Solution SIR: Spectrometric analysis of aqueous solutions of fatty amines has recently been reported (9). This method was extended by this laboratory to field use for samples containing 0 to 1.0 p.p,m. amine. We found that by combining the buffer and dye reagents, a combination-single reagent could be used. The procedure requires less sample and shows increased sensitivity over field methods previously reported which use bromophenol blue as the dye and chloroform as the extraction solvent (1). EXPERIMENTAL
Combination Reagent. Dissolve 0.1 gram of methyl orange in deionized water. Dissolve 29.6 grams of sodium acetate trihydrate and 50 grams of potassium chloride in deionized water. Combine t h e t w o solutions, add 100 ml. of glacial acetic acid, and dilute to 500 ml. with deionized water.
Table 1.
Data for Standard Curve
ODA, p.p.m. Blank (0) 0.10 0.20 0.33
0.50
0.54 0.76 1.oo 1.09
Methyl orange procedure 96 86 r-
Previous procedure 1L 00
i l
TO
53 50 40 34 30
Transmittance at 420 n u , R.
1760
ANALYTICAL CHEMISTRY
94 Stj -( I
63 65
55 47 43
Procedure. T o a 250-ml. separatory funnel add 100 ml. of the sample t o be tested. Add 5 ml. of the cornbined reagent and set aside for 10 minutes. Add 20 ml. of ethylene dichloride and shake for 5 minuter. Allow t h e layers t o separate for approximately 5 minutes. Drain off t h e lower layer and measure transmittance immediately at 420 m,u, RESULTS AND DISCUSSION
Data for a typical standard curve are shown in Table I. The curve is linear over the range of 0 to 1 p.p.m. Table I also shows the sensitivity of previously used procedures and of this method. the latter being approximately 50% more sensitive. A single reagent system presents an advantage for field use. The buffer and dye reagents were combined in proportion so that 5 ml. of the single reagent was essentially equivalent to 4 ml. of buffer and 2 ml. of dye solution. This reagent is stable for a t least 1 month without refrigeration. Silverstein (2) reports the reaction of \-arious amines to this procedure. Since this modification is similar in its reaction with octadecylamine (ODA), interferences are the same. Sample handling and sampling techniques should be the same. Silverstein showed that morphoIine and cyclohexylamine gave slightly positive results. Table I1 shows this effect to be negligible except where a relative error of better than =klOyois required. There ib only a slight variation between choloroform and ethylene dichloride, the latter
Table (I. Effect of Neutralizing Amines on ODA Determination
Amount Cj-clo- Amount Morpho- hexylODh OD.4, line, amine, recovered, p.p.m. p.p.m. p.p.m. p.p.ni. 0.0 0.0 0.54 CI 54
0.0 0.02 0.54 0.55
10
500
10
50
0 54 0 54 Ethylene
500
dichloride extraction 0 ,54 Ethylene dichloride extraction 0 54 Chloroform extraction I 09 Chloroform evtraction
0.61 0 5S
0.57 0 50 0 95
being more sensitive. Ethylene dichloride is preferred also because of its higher boiling point, LITERATURE CITED
(1) Bednar, G., Dugo, R. J., Abstracts,
Division of Water, Sewage, and Sanitation Chemistry, 134th meeting .4CS, Chicago, Ill., September 1958. ( 2 ) Silverstein, It. M., ANAL.CHEX 3 5 , 154 (1963). R. A. LARRICK
Anal>-ticalLaboratory Dearhorn Chemical Co. Chicago 9, Ill.
