acids. As ammonia is released along with phenol, the contact of these two compounds with 2,6-dichloroquinone-4chloroimine will result in the blue coloration that is characteristic of the Gibbs reaction. Phenol alkyl ethers are known to lose their alkyl groups when warmed with concentrated hydriodic acid:
+ HI +ArOH + RI
Ar-0-R
Nascent hydriodic acid is used in the present test for this dealkylation-Le.. the phenol ethers are heated with a mixture of potassium iodide and hydrated oxalic acid. The latter releases hydrogen iodide which, as a gas, reaches the phenol ether and they enter into the above reaction. As in the saponification of phenol esters, the steam set free from the oxalic acid dihydrate aids in volatilizing the phenols. The pyrohydrolysis of phenol esters b y means of oxalic acid and the dealkylation of phenol ethers with alkali iodide and oxalic acid are readily accomplished at 150" C. These effects as well as the pyroammonolysis of triphenyl phosphate, when combined with the indophenol reaction of the liberated phenols, lead to satisfactory tests for phenol esters and ethers that can be carried out readily within the bounds of spot test analysis. DETECTION OF PHENOL ESTERS OF CARBOXYLIC ACIDS
Procedure.
T h e test is conducted
in a micro test tube. Small amounts of t h e sample or 1 drop of its solution in alcohol are mixed with a b o u t 1 cg. of oxalic acid dihydrate, after taking the mixture t o dryness if necessary. T h e test tube is then placed in a glycerol bath t h a t has been preheated t o 150' C., and the mouth of the test tube is covered with a disk of freshly prepared reagent paper. After 1 to 2 minutes, the paper is held over concentrated ammonium hydroxide. A positive response is indicated by the development of a blue stain, whose intensity is a measure of the quantity of phenol ester present. The color of the spot either quickly fades to a dirty violet or disappears entirely. Renewed exposure to ammonia will restore the blue color. Reagent Paper. T h e filter paper is bathed in a saturated benzene solution of 2,6-dichloroquinone-4-chloroimine. The test revealed 10 to 20 y of the following compounds: phenyl acetate, phenyl benzoate, phenyl anthranilate, diphenyl carbonate, phenyl salicylate, and phenyl stearate.
250" C. A positive response is indicated by the appearance of a blue stain on the paper. The limit of identification is 5 y of triphenyl phosphate. DETECTION
OF PHENOL-ALKYL ETHERS
Procedure. A little of t h e sample or a drop or two of its solution in ordinary ether is placed in a micro test tube along with about 1 cg. of t h e reagent mixture. After taking to dryness if necessary, t h e test tube is closed with a disk of reagent paper and heated in a glycerol bath t o 150" C. After several minutes' heating, the paper is exposed to ammonia vapors. A blue stain indicates a positive response. Reagent Mixture. Equal weights of pulverized potassium iodide and oxalic acid dihydrate are mixed shortly before the test The test revealed 0.5 y of veratrole, 1.0 y of phenetole, 2.0 y of isoeugenol, 25 y of anethole, 10 y of phenoxyacetic acid, 20 y of m-phenetidine, 10 y of a,b-diphenoxyethane, 10 y of ethoxyphenoxyacetic acid, 2.5 y of p-dimethoxybenzene, 5 y of o-methoxybenzoic acid, 10 y of a,rdiphenoxypropane, and 2.5 y of guiacol benzoate.
DETECTION OF TRIPHENYL PHOSPHATE
Procedure. Small amounts of the sample or a drop of its solution are mixed in a micro test tube with several centigrams of guanidine carbonate and evaporated t o dryness if necessary. T h e test tube is placed in a glycerol b a t h previously heated t o 120' C. and t h e mouth of t h e tube is covered with a disk of freshly prepared reagent paper. The temperature of the bath is then increased to
LITERATURE CITED
(1) Feid. F.. Anaew. Chem. 70.166 (1958). (2) Feigl; F:, H"aguenauer, D., JGngreis, E., Talanta 1, 80 (1958).
(3) Feigl, F., Jungreis, E., AXAL.CHEM. 31, 2099 (1959).
RECEIVED for review May 14, 1958. Accepted September 23, 1959.
Separation of Boron from Alloys and Other Materials by Pyrohydrolysis SIR: It has been found possible to separate boron from metals and alloys such as zirconium, Zircaloy, Zircaloybase uranium alloys, stainless steels, and other materials such as boron carbide by pyrohydrolysis. T h e method which follows has been a.pplied to the determination of boron in the above materials as well as to the separation of boron in a pure form from various matrices for isotopic analysis of the element. The method is adaptable t o remot,e operation and should prove useful in isolating boron from radioactive matrices whose level of activity complicates the direct application of boron color reagents or conventional methods of separation.
Pyrohydrolysis Apparatus. Nickel tube, 34 inches long, 13/16 inch in inside diameter, l l / l s inches in outside 2102
ANALYTICAL CHEMISTRY
Table
I.
Determination
of
Boron in Various Materials
(Analysis by mannitol titration or spectrophotometrically with quinalizarin) Type of Material
Boron Present, 70
Boron Found by Pyrohydrolysis, yo
76.7 P.P.RI. 303 303 168
77:i;-75.9 P.P.M. 3005 316, 3 B b 179, 169, 181, 168, 163, 175 488"
Boron-stainless steel alloy Boron carbide technical grade Boron carbide high purity Boron carbide sintered disks Zircaloy-base uranium alloy Zircaloy-base uranium alloy Boron carbideuranium dioxide mixture Boron-uranium dioxide mixture a
500
Single analysis. Samples pyrohydrolyzed a t 1300' C. for 0.5 hour.
diameter, equipped at one end with a side a r m for t h e admission of steam a n d at t h e other end with a copperjacketed condenser. Steam generator connected t o t h e nickel t u b e b y Tygon or heavy-walled rubber tubing. Resistance-type tube-furnace capable of obtaining 1400' C. The finely divided powder or machine chip sample is weighed into a small nickel or platinum boat. The boat is inserted into the tube and steam is passed over the sample for 1*/2hours a t a furnace temperature of 1100' C. The steam flow is regulated to produce 1 to 3 ml. of distillate per minute. The distillate is collected in a Teflon beaker containing 20 ml. of distilled water and sufficient base to keep the solution alkaline. The boron in the distillate may be analyzcd by a n y of the conventional methods for the element, the level determining the mode of analysis. The distillates obtained from the materials analyzed t o date have been completely free of interfering elements. EXPERIMENTAL WORK
I n most of the work reported here, a
temperature of 1100" C. has been used for the pyrohydrolytic process. Several runs made a t 1300" C. indicate that boron can be quantitatively separated in 30 minutes, but the life of the nickel tube is shortened considerably a t this higher temperature. Alloys such as Stellites and Inconel, which are more stable a t the higher proposed temperatures of operation (1300" C.), are being investigated as possible tube materials. The use of platinum or platinum-clad base metal is also being considered. The rate a t which the steam is passed over the sample (1 t o 3 ml. per minute) has little effect upon the rate of separation of boron. The effectiveness of separation of boron by pyrohydrolysis is illustrated b y the data in Table I. The method appears to be almost universally applicable t o the separation of boron from various matrices, including even very refractory materials. The dissolution of such materials, frequently by lengthy fusion methods, is not necessary if the
pyrohydrolysis method of boron separation is employed. A complete study of the parameters and mechanism of this xllethod of boron separation is being performed. A detailed paper, including all findings, mill be published later. During the course of this work, the separation of boric oxide from glasses by pyrohydrolysis was reported by Williams and coworkers (1). LITERATURE CITED
( 1 ) Williams, J. P., Campbell, D. E., Magliocca, T. S , ANAL. CHEX 31,
1560 (1959).
V. R. WIEDERKEHR G . W. GOWARD Bettis Atomic Power Laboratory Westinghouse Electric Corp. Pittsburgh, Pa. RECEIVED for review September 23, 1959. Accepted October 5, 1959. Work s u p ported by the U. S. Atomic Energy Commission under contract AT-11-1-GEN-14 with the Westinghouse Electric Corp., Bettis Atomic Power Laboratory.
Determination of a Substituted Glycol by EIe ct roIytic Oxid a ti o n SIR: Examination of the literature shows no electrolytic oxidation of glycols as a n analytical technique. Allen has only three references to the electrolytic cleavage of glycols of any kind ( I ) . The compound phenaglycodol, which has the chemical name 2-p-chlorophenyl3-methy1-2,3-butanediol, has been found to be split by electrolytic oxidation to give a product having an ultraviolet absorption spectrum with a potential use for quantitative analytical applications. The procedure is being published now because of the novel nature of the reaction. It is unlikely that any further publication on this subject will come from these laboratories. The physiological properties of phenaglycodol have been discussed ( 2 ) . The reaction taking place during electrolysis niay presumably be written as follows: OH OH Cq-$L-CHs
0
p-chloroacetophenone and of the oxidation product, indicating that the oxidation product has no other interfering ultraviolet absorption except perhaps for a slight absorption due to acetone at short wave lengths. Phenaglycodol itself shows only weak absorption to the p-chlorophenyl group. APPARATUS
WA/E .rVd-?
V
Figure 1. Ultraviolet absorption curves -Authentic pchloroacetophenone (0.0161 mg./ml.) in water Oxidation product from typical run
---
+
AH3LIIJ
P
CHs C-CHa
+ Ha0
No attempt was made to study the kinetics of the reaction or t o determine the amount of acetone formed. Figure 1 shows the correspondence of the ultraviolet absorption spectrum of known
The electrolysis cell used was a 300m1.-high side beaker closed by a rubber stopper through which passed a condenser, the anode, and the cathode compartment. The anode was a commerci:i11y available platinum gauze of the type used as a cathode in electrolytic copper determinations. 'lhc cathode coinpartmerit was simply a piece of 12-niiii. glass tubing with a tight plug of filter paper as a diaphragm a t the bottom. A spiral of copper n.ire served as the cathode and 31" sulfuric acid served as the catholyte. The direct current p o w r supply was a simple variable transformer and selenium rectifier conibinntion of the type used to power HO model trains. The combination used \vas manufactured by Scintilla Rail arid Power Works, 324 Lafayette St., Ncm York, N. Y. According to the manufacturer, the unit has a continuous rating of 1 ampere a t 12 volts. This unit provides only pulsating direct current and no VOL. 31,
NO. 12,
DECEMBER 1959
2103
