Use of Perchloryl

SIR: A preliminary study of the possible use of perchloryl fluoride as an excitation fuel in flame photometry produced encouraging results. Per- chloryl fluoride (PF), C103F, is a color- less noncorrosive gas with a charac- teristic sweet odor. It is storable as a liquid under pressure and exhibits oxidizing properties. Perchloryl fluo- ride and hydrogen, as a gas combination, burned in a modified Beckman burner and produced an easily controlled, bluish flame with sufficiently low back- ground for use as an excitation source. Less than 2% background emission was produced with a 0.2-mm. slit width.

The type spectra produced by the hydrogen-perchloryl fluoride flame with various series of solutions n-ere surveyed t o determine the effectiveness of this gas combination in flame photometric work. The various lines and bands produced by three gas combinations were compared, including acetylene- oxygen, hydrogen-fluorine, and hpdro- gen-perchloryl fluoride.

EXPERIMENTAL

A standard acetylene-oxygen burner supplied by Beckman Instruments, Inc., was modified for this work. An automatic recording spectrophotometer was used as a detecting instrument. The monochromator unit was the Beckman Model DC spectrophotom- eter with the automatic recording unit supplied by Warren Electronics, Inc. A Fischer-Porter C-clamp Flow- rator was used to measure the flow rate of the atomizing gas.

The burner was mounted in place of the light source for the automatic recording spectrophotometer. The dis- tance from the burner to the lamp housing was 8 inches. A double convex quartz lens was used to focus the light emitted by the flame upon the slit entrance of the instrument.

Fluoride in Flame Photometry

Solutions were prepared from the chlorides of lithium, sodium, barium, magnesium, strontium, calcium, iron, chromium, and copper in the concen- tration of 1000 p.p.m. of the metal ions. Water, dimethylformamide, and di- methylsulfoxide were used as solvents. Spectra were obtained for these solutions in both the acetylene-oxygen and the hydrogen-perchloryl fluoride flames. Data concerning the effect of the hydrogen-fluorine flame were obtained from Collier (1).

RESULTS

The hydrogen-perchloryl fluoride gas combination produced a satisfactory excitation source for flame photometry, which is easily controlled and has a low background. A flow rate of 4000 to 5000 cc. of perchloryl fluoride per minute and 11,000 to 12,000 cc. of hydrogen per minute provided the best flame conditions. Below this flow rate for the perchloryl fluoride, the aspira- tion is insufficient to provide proper flame intensity. Ahoye this rate, the intensity again decreases and the

flame becomes unsteadj-. The tempers- ture of this flame has not yet been determined.

The acetylene-oxygen flame produced a background of 2 to 5% emission in the visible region when a 0.05-mni. slit was used, and the reported maximum flame temperature is 3410" K. The hydrogen-fluorine flame produced about 1% background emission in the visible region with a 0.05-mm. slit, and the reported maximum flame temperature ie 4300" K.

Figures 1 and 2 illustrate the type spectra produced by the three flames under consideration. Comparison of the radiation emitted by the hydrogen- perchloryl fluoride, acetylene-oxygen , and hydrogen-fluorine flames upon in- jection of metal salt solutions, s h o w that primarily atomic line and metal oxide band radiation is produced by the acetylene-oxygen flame (Figure 1) and primarily atomic line and metal fluoridP and chloride band radiation is produced by the hydrogen-perchloryl fluoride flame (Figure 1). According to Col!ier (I), the hj-drogen-fluorine flame pro-

I .o 1000 P P M MO*IR DMF 1000 PPM MO*IN DMF

HE- PF O . l r r S L I T C.He- 0. 0 . 1 ~ ~ S L I T

( S O L I D L INE) I EROKW L I N E )

1 MECI ,

WAVE L E N G T H

Figure 1. Relation between wave length and intensity

O F

.Mo F

1000PPM Mot+ I N H e 0

He- F, 0.05Nu SLIT

Ma A

350 400 500 600 700 WAVE LENGTH

Figure 2. Relation between wave length and intensity

1 1 6 0 ANALYTICAL CHEMISTRY

CAF 1.0

500 PPM Cl"8 M t t I * O M F

HE- PF 0 .PuuSLIT - Ma CAF

>,

WAVE LENGTH

Figure 3. Relation between wave length and intensity

duced primarily atomic line and metal fluoride band radiation for the elements studied (Figure 2). Both the hydrogen- fluorine and the hydrogen-perchloryl fluoride flames are capable of producing the same type of radiation; however, the lines and bands produced by the former are generally more intense.

I n general, the solvent does not affect the type of radiation observed for a particular element when excited with the hydrogen-perchloryl fluoride flame, but the organic solvents seem t o produce higher intensity under similar condi- tions. A comparison of the spectra produced by these three flames for 1000 p.p.m. of magnesium is shown in Figures 1 and 2. The acetylene-oxygen flame produced two broad magnesium oxide bands in the region between 360 and 400 mp, while the hydrogen-perchloryl fluoride flame produced two prominent, fairly narrow bands and two less proniinent bands in this region. The two prominent bands are a magnesium fluoride band at 359.4 nip and a mag- nesium chloride band a t 377.0 mp. The two less prominent bafids are also magnesium chloride bands. These bands were identified Tvith the aid of tables compiled by Pearse and Gaydon ( 2 ) for the identification of molecular spectra.

In Figure 2, the spectrum of 1000 p.p.m. of magnesium in water shows one

very intense magnesium fluoride band at 359.4 mp and two less intense mag- nesium fluoride bands when excited by the hydrogen-fluorine flame using a 0.05-mm. slit.

A solution of 500 p.p.m. each of cal- cium and magnesium in dimethyl- formamide produced a spectrum charac- teristic of both individual elements, with no overlapping of prominent lines (Figure 3). The lines and bands pro- duced for calcium were much more intense than those for magnesium. The same type of spectrum was produced for the calcium-magnesium mixture in mater but with less intensity.

CONCLUSIONS

A modified Beckrnan burner can be used for the hydrogen-perchlory1 fluo- ride gas combination to produce a satis- factory flame with very low background, which is easily controlled and applicable to use as an excitation source in flame photometry. Primarily atomic line and metal fluoride and chloride band radia- tion was produced upon excitation of the various elements by the hydrogen- perchloryl fluoride flame. Satisfactory spectra are produced by this gas com- bination for inany metals which would be suitable for analytical purposes. Despite high oxygen content in the flame, oxide bands of refractory metal oxides

were a minor interference with the H3 + PF flame. TWO very prominent bands are ob-

served when magnesium is excited by the hydrogen-perchloryl fluoride flame and a mixture of magnesium and cal- cium provided a spectrum characteristic of both individual elements with no overlapping of prominent lines or band. which suggest possible analytical adap- tation. The type of radiation for a par- ticular element is not affected by the solvent used, although the organic solvents produced better sensitivity than the corresponding water solutions.

ACKNOWLEDGMENT

The authors wish to thank Pennsalt Chemicals Corp. for supplying the perchloryl fluoride used in this work.

LITERATURE CITED

(1) Collier, H. E., unpublished Ph.D. thesis, Lehigh University, June 1955.

(2) Peyse, R. TV., Gaydon, A. G., ‘Identification of Molecular

Spectra,” Chapman & Hall, London, 1941.

GEORQE E. SCHXkcCH EARL J. SERFASS

Chemistry Department Lehigh University Bethlehem, Pa. RECEIVED for review November 2, 1957. Accepted dpril 12, 1958.

170. Germanium Bismuthate, Ge,Bi,O,,

ANDRE DURIF Laboratoire d’Electrostatique et de Physique du MBtal, lnstitut Fourier, Grenoble, France

ERMAPI‘IUM bisniuthate n-as pre- and germanium dioxide (1). This corn- X-RAY DIFFRACTIOX DATA G pared b y heating slovJy up t o 850” C. a mixture of bismuth trioxide eulytine, Si3Bi4012, also called agricolite. cel l size. a = 10.527 0.003 -1.

pound is a n isomorph of the mineral System. Cubic,

Formula weights per cell. 4. Density. 7.049 grams per cc. (calcu-

Table I. X-Ray Powder Diffraction Data for Germanium Bisrnuthatea lated).

h1:l dobsd. dcaicd. I , . is, hkl dobad . doalcd. I\.,,. Space group. T: -143d. 211 4.24 4.30 niS 444 1.514 1.519 IT Precision measurements have been 310 3.26 3.33 S 550 1 made both with powder camera (filtered

1.436 1.489 m3 cobalt and copper radiations) and with the x-ray diffractometer (monoehro-

312 2.76 2.81 S 100 2 .59 2.63 mW

in3 552 1 inatized copper radiation K a l ) (Table 422 2.12 2.15 1.431 1.133 m

,721 1.915 1.922 IT’ 642 1.404 1.407 m 530’ 7327 43;3( 1.798 1.805 n1 A,51/ 1.335 1.337 m\J7

E; 1 1). f!:j) 2 .04 2.06 mS ;:; ,f

LITERATURE CITED

!&’; 1.704 1.708 mS . . ~

1 296 1.298 mS (1) Durif, A., Compt. rend. 244, 2815-17 554 (1957). 620‘ 1.661 1.664 mTV

541 1 G19 1.624 mS 653 1.258 1.259 TV 6:31 1 548 1 552 mS 34 more indexable lines were observed and measured with copper radiation CRYSTALLOGRAPHIC data for publication in

this section should be sent to W. C. Mc- Crone, 500 East 33rd St., Chicago 16, Ill.

VOL. 30, NO. 6, JUNE 1958 1161